Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sun, 02/18/2018 - 10:03
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1001 AM CST Sun Feb 18 2018 Valid 181700Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN COLORADO...NORTHEASTERN NEW MEXICO...WESTERN KANSAS...AND PORTIONS OF THE OKLAHOMA AND TEXAS PANHANDLES... Areal expansions were made to the elevated and critical areas for this update. Portions of east-central Colorado were included in critical (near and north of the Pueblo area) where wind speeds around 20 mph (with higher gusts) will exist for a few hours amidst critically low RH values (around 5-15%). Additionally, more of north-central and central Colorado were added to the ongoing elevated area. Here, RH values will fall below 15% during the afternoon although winds are expected to be somewhat lighter (5-15 mph) compared to areas farther south. The elevated area was also expanded eastward to include more of central Kansas and northwestern Oklahoma. Here, the fire weather risk is driven mostly by strong south-southwesterly winds (25-35 mph with a few higher gusts) as RH values should only fall to around the 25-35% range. See the previous discussion below for more information. ..Cook.. 02/18/2018 .PREV DISCUSSION... /ISSUED 0206 AM CST Sun Feb 18 2018/ ...Synopsis... The upper-level pattern will amplify on Sunday as a trough deepens over the West. In response, midlevel southwesterly flow will increase over the central/southern High Plains. At the surface, a low pressure system is forecast to strengthen over northeastern Colorado during the afternoon while a high pressure system moves toward the Mid-Atlantic Coast. ...Portions of the Southern/Central High Plains... A strong surface pressure gradient combined with downward vertical mixing of enhanced flow aloft will result in windy conditions across the region. Sustained afternoon southwesterly surface winds of 15-30 mph are forecast with the strongest winds expected across northeastern New Mexico and the Oklahoma/Texas panhandles. Downslope flow will support critical RH values across much of eastern Colorado, but northward moisture advection will tend to limit the southward and eastward extent of critical RH values. Despite a spatial offset of the strongest winds (i.e., to the south) and lowest RH values (i.e., to the north), there will be sufficient overlap of strong winds/low RH from northeastern New Mexico into western Kansas to result in critical fire weather conditions for a few hours in the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sun, 02/18/2018 - 10:03
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1001 AM CST Sun Feb 18 2018 Valid 181700Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN COLORADO...NORTHEASTERN NEW MEXICO...WESTERN KANSAS...AND PORTIONS OF THE OKLAHOMA AND TEXAS PANHANDLES... Areal expansions were made to the elevated and critical areas for this update. Portions of east-central Colorado were included in critical (near and north of the Pueblo area) where wind speeds around 20 mph (with higher gusts) will exist for a few hours amidst critically low RH values (around 5-15%). Additionally, more of north-central and central Colorado were added to the ongoing elevated area. Here, RH values will fall below 15% during the afternoon although winds are expected to be somewhat lighter (5-15 mph) compared to areas farther south. The elevated area was also expanded eastward to include more of central Kansas and northwestern Oklahoma. Here, the fire weather risk is driven mostly by strong south-southwesterly winds (25-35 mph with a few higher gusts) as RH values should only fall to around the 25-35% range. See the previous discussion below for more information. ..Cook.. 02/18/2018 .PREV DISCUSSION... /ISSUED 0206 AM CST Sun Feb 18 2018/ ...Synopsis... The upper-level pattern will amplify on Sunday as a trough deepens over the West. In response, midlevel southwesterly flow will increase over the central/southern High Plains. At the surface, a low pressure system is forecast to strengthen over northeastern Colorado during the afternoon while a high pressure system moves toward the Mid-Atlantic Coast. ...Portions of the Southern/Central High Plains... A strong surface pressure gradient combined with downward vertical mixing of enhanced flow aloft will result in windy conditions across the region. Sustained afternoon southwesterly surface winds of 15-30 mph are forecast with the strongest winds expected across northeastern New Mexico and the Oklahoma/Texas panhandles. Downslope flow will support critical RH values across much of eastern Colorado, but northward moisture advection will tend to limit the southward and eastward extent of critical RH values. Despite a spatial offset of the strongest winds (i.e., to the south) and lowest RH values (i.e., to the north), there will be sufficient overlap of strong winds/low RH from northeastern New Mexico into western Kansas to result in critical fire weather conditions for a few hours in the afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 02/18/2018 - 05:50

000
AXNT20 KNHC 181149
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
649 AM EST Sun Feb 18 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1145 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
continues between a surface high pressure in the western Atlantic
and lower surface pressure in northern sections of South America.
This pattern supports winds pulsing to minimal gale force near
the coast of Colombia through early next week. The resultant wave
heights with the gale-force winds will range between 12-16 ft. Please
read the latest NHC High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the southern coastal
sections of Liberia near 05N08W southwestward dipping to below
the Equator at 18W as the ITCZ axis to 03S27W and to the coast
of Brazil near 04S38W. Scattered moderate isolated convection is
within 60 nm S of the ITCZ axis between 24W and 28W. Similar
convection is just to the N of the Equator within 30 nm of line
from 01N27W to 02N31W to 02N34W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from an Atlantic Ocean 1026 mb high
pressure center located near 28N64W, to across central Florida,
to a 1023 mb nearly stationary high centered at 27N83W and
continues west-northwestward to the NW Gulf near 28N94W. A weak
surface trough is analyzed over the NE Gulf from near
Apalachicola to 28N87W to 27N89W. Isolated weak showers are
possible along the trough. Similar showers are over the extreme
southeastern gulf near NW Cuba. The ridge will continue to
maintain mainly gentle to moderate southeast winds in the western
Gulf, and light to gentle east to southeast elsewhere through
Sun night with the exception of moderate winds over the SE
waters and the Straits of Florida. Areas of dense fog producing
reduced visibility to below 1 nm are again expected through this
morning mainly N of 27N, persisting into this afternoon over
some locations. Isolated showers are over some portions of the
eastern gulf and far SE waters near the Straits of Florida.
Expect increasing winds and building seas by early next week as
high pressure strengthens in the western Atlantic Ocean. A
thermal trough will develop over the western Yucatan Peninsula
during each afternoon. The trough will drift westward across the
eastern Bay of Campeche during the overnight hours, and then
dissipate in the SW Gulf waters by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Patches of broken to at times overcast low clouds with isolated
showers are quickly moving westward across the western and central
Caribbean N of about 14N, including waters adjacent to the
southwest tip of Haiti and waters just east and west of Jamaica.
Similar clouds with brief passing isolated showers are noted
over portions of the eastern Caribbean. Over the eastern
Caribbean, the moisture coverage has decreased since yesterday as
very dry air aloft has moved into that portion of the sea.

A tight pressure gradient between a high pressure system that is
in the western Atlantic Ocean, and lower pressure in northern
sections of South America, will continue to support pulsing winds
of minimal gale force near the coast of Colombia through early
next week. Fresh to locally strong trade winds are expected
elsewhere across the Caribbean Sea. The high pressure will be
reinforced by a stronger high pressure system on Mon. The stronger
system will bring increasing winds and building seas across the
eastern and central Caribbean Sea, and the Tropical N Atlantic
waters possibly into the middle of next week.

ATLANTIC OCEAN...

A central Atlantic upper level trough enters the area through
32N25W, and stretches southwestward to an elongated cyclonic
circulation that is dropping southward near 24N43W, and continues
southwestward to 15N51W where it becomes a cyclonic shear axis
westward to 14N58W and to the eastern Caribbean Sea near 14N66W.
A surface trough extends from 31N50W to 26N58W, and another one
extends from near 29N43W to 24N44W to 19N44W. Isolated showers and
thunderstorms are noted within 240 nm to the E of the second
trough, and within 60 nm W of the same trough from 20N to 23N.
Isolated showers are near the first trough. Other than these
troughs, the Atlantic is dominated by high pressure as a nearly
1026 mb high center is near 28N64.5W, and another 1026 mb high
center is over the eastern Atlantic near 29N38W. A ridge extends
from the 1026 mb high at 28N64.5W westward to across central
Florida. In the upper levels, an anticyclone is near 22N66W, with
its broad anticyclonic flow covering just about the entire western
half of the area. An upper level trough has entered the far NW
corner of the area. Subsidence and dry air aloft associated with
the upper anticyclone is suppressing any deep convection from
developing. The upper trough is void of any shower activity as it
nudges into a very stable atmospheric environment. Isolated
showers are seen over the waters between Andros Island and the
Straits of Florida. The aforementioned high pressure ridge will
retreat eastward today allowing for a weak cold front to move off
the southeastern United States coast. The front will quickly
become stationary and dissipate across the northwest portion on
Mon. Gentle to moderate south to southwest winds will prevail to
the north of the ridge, with moderate to fresh winds expected
generally to the south of 25N, except becoming strong along the
north coast of Hispaniola and the northern approach to the
Windward Passage each evening. The ridge will be reinforced by a
stronger high pressure system on Mon through Tue.

Over the eastern portion of the Atlantic, extensive mid and upper
level moisture in the form of overcast to broken mid and high
level clouds are observed streaming northeastward from
northeastern S America to within 300 nm either side of a line
from 05N51W to 13N37W to 17N28W to 18N23W where the moisture thins
out allowing for the clouds to transition to mainly scattered high
clouds to inland the coast of Africa at 19N16W. This area of
moisture and clouds are driven by a rather strong jet stream
branch that is along the southeast sector of the upper level
trough described above. Scattered moderate convection is along
and just inland the coast of S America between 43W-47W. Isolated
showers are possible elsewhere from 02N-11N between 41W-51W, and
also from 10N-19N between 30W-41W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
JA/ERA

Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 02/18/2018 - 03:27

000
AXNT20 KNHC 180927 AAA
TWDAT

Tropical Weather Discussion...Updated
NWS National Hurricane Center Miami FL
427 AM EST Sun Feb 18 2018

Updated Monsoon Trough/ITCZ Section

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0530 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient,
that exists between surface high pressure in the western Atlantic
Ocean, and lower surface pressure in northern sections of South
America, should continue to support winds pulsing to minimal
gale force near the coast of Colombia through early next week.
The resultant wave heights with the gale force NE to E winds are
forecast to range from 12 to 16 feet, except building to 12 to 18
ft Mon. Please read the latest NHC High Seas Forecast under
AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...Updated

The monsoon trough axis extends from the southern coastal
sections of Liberia near 05N08W southwestward dipping to below
the Equator at 18W as the ITCZ axis to 03S27W and to the coast
of Brazil near 04S38W. Scattered moderate isolated convection is
within 60 nm S of the ITCZ axis between 24W and 28W. Similar
convection is just to the N of the Equator within 30 nm of line
from 01N27W to 02N31W to 02N34W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from an Atlantic Ocean 1026 mb high
pressure center located near 28N64W, to across central Florida,
to a 1023 mb nearly stationary high centered at 27N83W and
continues west-northwestward to the NW Gulf near 28N94W. A weak
surface trough is analyzed over the NE Gulf from near
Apalachicola to 28N87W to 27N89W. Isolated weak showers are
possible along the trough. Similar showers are over the extreme
southeastern gulf near NW Cuba. The ridge will continue to
maintain mainly gentle to moderate southeast winds in the western
Gulf, and light to gentle east to southeast elsewhere through
Sun night with the exception of moderate winds over the SE
waters and the Straits of Florida. Areas of dense fog producing
reduced visibility to below 1 nm are again expected through this
morning mainly N of 27N, persisting into this afternoon over
some locations. Isolated showers are over some portions of the
eastern gulf and far SE waters near the Straits of Florida.
Expect increasing winds and building seas by early next week as
high pressure strengthens in the western Atlantic Ocean. A
thermal trough will develop over the western Yucatan Peninsula
during each afternoon. The trough will drift westward across the
eastern Bay of Campeche during the overnight hours, and then
dissipate in the SW Gulf waters by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Patches of broken to at times overcast low clouds with isolated
showers are quickly moving westward across the western and central
Caribbean N of about 14N, including waters adjacent to the
southwest tip of Haiti and waters just east and west of Jamaica.
Similar clouds with brief passing isolated showers are noted
over portions of the eastern Caribbean. Over the eastern
Caribbean, the moisture coverage has decreased since yesterday as
very dry air aloft has moved into that portion of the sea.

A tight pressure gradient between a high pressure system that is
in the western Atlantic Ocean, and lower pressure in northern
sections of South America, will continue to support pulsing winds
of minimal gale force near the coast of Colombia through early
next week. Fresh to locally strong trade winds are expected
elsewhere across the Caribbean Sea. The high pressure will be
reinforced by a stronger high pressure system on Mon. The stronger
system will bring increasing winds and building seas across the
eastern and central Caribbean Sea, and the Tropical N Atlantic
waters possibly into the middle of next week.

ATLANTIC OCEAN...

A central Atlantic upper level trough enters the area through
32N25W, and stretches southwestward to an elongated cyclonic
circulation that is dropping southward near 24N43W, and continues
southwestward to 15N51W where it becomes a cyclonic shear axis
westward to 14N58W and to the eastern Caribbean Sea near 14N66W.
A surface trough extends from 31N50W to 26N58W, and another one
extends from near 29N43W to 24N44W to 19N44W. Isolated showers and
thunderstorms are noted within 240 nm to the E of the second
trough, and within 60 nm W of the same trough from 20N to 23N.
Isolated showers are near the first trough. Other than these
troughs, the Atlantic is dominated by high pressure as a nearly
1026 mb high center is near 28N64.5W, and another 1026 mb high
center is over the eastern Atlantic near 29N38W. A ridge extends
from the 1026 mb high at 28N64.5W westward to across central
Florida. In the upper levels, an anticyclone is near 22N66W, with
its broad anticyclonic flow covering just about the entire western
half of the area. An upper level trough has entered the far NW
corner of the area. Subsidence and dry air aloft associated with
the upper anticyclone is suppressing any deep convection from
developing. The upper trough is void of any shower activity as it
nudges into a very stable atmospheric environment. Isolated
showers are seen over the waters between Andros Island and the
Straits of Florida. The aforementioned high pressure ridge will
retreat eastward today allowing for a weak cold front to move off
the southeastern United States coast. The front will quickly
become stationary and dissipate across the northwest portion on
Mon. Gentle to moderate south to southwest winds will prevail to
the north of the ridge, with moderate to fresh winds expected
generally to the south of 25N, except becoming strong along the
north coast of Hispaniola and the northern approach to the
Windward Passage each evening. The ridge will be reinforced by a
stronger high pressure system on Mon through Tue.

Over the eastern portion of the Atlantic, extensive mid and upper
level moisture in the form of overcast to broken mid and high
level clouds are observed streaming northeastward from
northeastern S America to within 300 nm either side of a line
from 05N51W to 13N37W to 17N28W to 18N23W where the moisture thins
out allowing for the clouds to transition to mainly scattered high
clouds to inland the coast of Africa at 19N16W. This area of
moisture and clouds are driven by a rather strong jet stream
branch that is along the southeast sector of the upper level
trough described above. Scattered moderate convection is along
and just inland the coast of S America between 43W-47W. Isolated
showers are possible elsewhere from 02N-11N between 41W-51W, and
also from 10N-19N between 30W-41W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Aguirre
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sun, 02/18/2018 - 02:11
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0207 AM CST Sun Feb 18 2018 Valid 191200Z - 201200Z ...Synopsis... A deep trough over the West is forecast to advance eastward toward the Rockies on Monday as a midlevel speed max rotates through the base of the trough. This upper-level pattern will support continued strong southwesterly midlevel flow across much of the central/southern High Plains. At the surface, a low pressure system will lift off to the northeast toward the Upper Mississippi River Valley with a trailing cold front connecting back to a developing low pressure system over Colorado during the afternoon. ...Portions of the Southern High Plains... Given the presence of a rapidly strengthening low pressure system over Colorado and enhanced flow aloft, surface conditions will be windy (sustained southwesterly winds of 25-30 mph) across the southern High Plains during the afternoon hours. The limiting factor to widespread critical fire weather conditions will be marginal RH values, which are forecast to remain at or above 25% even for the models with the most aggressive mixing schemes in the PBL. Consequently, only elevated conditions are highlighted in this outlook, where RH values are mostly likely to approach critical thresholds. An expansion of the elevated area and the addition of a critical area may be needed if confidence increases in critical RH potential. ..Jirak.. 02/18/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sun, 02/18/2018 - 02:09
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0206 AM CST Sun Feb 18 2018 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN NEW MEXICO EXTENDING NORTHEASTWARD TO WESTERN KANSAS... ...Synopsis... The upper-level pattern will amplify on Sunday as a trough deepens over the West. In response, midlevel southwesterly flow will increase over the central/southern High Plains. At the surface, a low pressure system is forecast to strengthen over northeastern Colorado during the afternoon while a high pressure system moves toward the Mid-Atlantic Coast. ...Portions of the Southern/Central High Plains... A strong surface pressure gradient combined with downward vertical mixing of enhanced flow aloft will result in windy conditions across the region. Sustained afternoon southwesterly surface winds of 15-30 mph are forecast with the strongest winds expected across northeastern New Mexico and the Oklahoma/Texas panhandles. Downslope flow will support critical RH values across much of eastern Colorado, but northward moisture advection will tend to limit the southward and eastward extent of critical RH values. Despite a spatial offset of the strongest winds (i.e., to the south) and lowest RH values (i.e., to the north), there will be sufficient overlap of strong winds/low RH from northeastern New Mexico into western Kansas to result in critical fire weather conditions for a few hours in the afternoon. ..Jirak.. 02/18/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 02/17/2018 - 23:51

000
AXNT20 KNHC 180550
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1250 AM EST Sun Feb 18 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0530 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient,
that exists between surface high pressure in the western Atlantic
Ocean, and lower surface pressure in northern sections of South
America, should continue to support winds pulsing to minimal
gale force near the coast of Colombia through early next week.
The resultant wave heights with the gale force NE to E winds are
forecast to range from 12 to 16 feet, except building to 12 to 18
ft Mon. Please read the latest NHC High Seas Forecast under
AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the southern coastal
sections of Liberia near 05N08W southwestward dipping to below
the Equator at 18W as the ITCZ axis to 03S27W and to the coast of
Brazil near 04S38W. Scattered moderate convection is within 60 nm
S of the ITCZ axis between 24W and 28W. Similar convection is
just to the N of the Equator within 30 nm of line from 01N27W to
02N31W to 02N34W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from an Atlantic Ocean 1026 mb high
pressure center located near 28N64W, to across central Florida,
to a 1023 mb nearly stationary high centered at 27N83W and
continues west-northwestward to the NW Gulf near 28N94W. A weak
surface trough is analyzed over the NE Gulf from near
Apalachicola to 28N87W to 27N89W. Isolated weak showers are
possible along the trough. Similar showers are over the extreme
southeastern gulf near NW Cuba. The ridge will continue to
maintain mainly gentle to moderate southeast winds in the western
Gulf, and light to gentle east to southeast elsewhere through Sun
night with the exception of moderate winds in the SE waters and
the Straits of Florida. Areas of dense fog producing reduced
visibility to below 1 nm are again expected through this morning
mainly N of 27N, persisting into this afternoon over some
locations. Isolated showers are over some portions of the eastern
gulf and far SE waters near the Straits of Florida. Expect
increasing winds and building seas by early next week as high
pressure strengthens in the western Atlantic Ocean. A thermal
trough will develop in the western Yucatan Peninsula during each
afternoon. The trough will drift westward across the eastern Bay
of Campeche during the overnight hours, and then dissipate in the
SW Gulf waters by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Patches of broken to at times overcast low clouds with isolated
showers are quickly moving westward across the western and central
Caribbean N of about 14N, including waters adjacent to the
southwest tip of Haiti and waters just east and west of Jamaica.
Similar clouds with brief passing isolated showers are noted
over portions of the eastern Caribbean. Over the eastern
Caribbean, the moisture coverage has decreased since yesterday as
very dry aloft has moved into that portion of the sea.

A tight pressure gradient between a high pressure system that is
in the western Atlantic Ocean, and lower pressure in northern
sections of South America, will continue to support pulsing winds
of minimal gale force near the coast of Colombia through early
next week. Fresh to locally strong trade winds are expected
elsewhere across the Caribbean Sea. The high pressure will be
reinforced by a stronger high pressure system on Mon. The stronger
system will bring increasing winds and building seas across the
eastern and central Caribbean Sea, and the Tropical N Atlantic
waters possibly into the middle of next week.

ATLANTIC OCEAN...

A central Atlantic upper level trough enters the area through
32N25W, and stretches southwestward to an elongated cyclonic
circulation that is dropping southward near 24N43W, and continues
southwestward to 15N51W where it becomes a cyclonic shear axis
westward to 14N58W and to the eastern Caribbean Sea near 14N66W.
A surface trough extends from 31N50W to 26N58W, and another one
extends from near 29N43W to 24N44W to 19N44W. Isolated showers and
thunderstorms are noted within 240 nm to the E of the second
trough, and within 60 nm W of the same trough from 20N to 23N.
Isolated showers are near the first trough. Other than these
troughs, the Atlantic is dominated by high pressure as a nearly
1026 mb high center is near 28N64.5W, and another 1026 mb high
center is over the eastern Atlantic near 29N38W. A ridge extends
from the 1026 mb high at 28N64.5W westward to across central
Florida. In the upper levels, an anticyclone is near 22N66W, with
its broad anticyclonic flow covering just about the entire western
half of the area. An upper level trough has entered the far NW
corner of the area. Subsidence and dry air aloft associated with
the upper anticyclone is suppressing any deep convection from
developing. The upper trough is void of any shower activity as it
nudges into a very stable atmospheric environment. Isolated
showers are seen over the waters between Andros Island and the
Straits of Florida. The aforementioned high pressure ridge will
retreat eastward today allowing for a weak cold front to move off
the southeastern United States coast. The front will quickly
become stationary and dissipate across the northwest portion on
Mon. Gentle to moderate south to southwest winds will prevail to
the north of the ridge, with moderate to fresh winds expected
generally to the south of 25N, except becoming strong along the
north coast of Hispaniola and the northern approach to the
Windward Passage each evening. The ridge will be reinforced by a
stronger high pressure system on Mon through Tue.

Over the eastern portion of the Atlantic, extensive mid and upper
level moisture in the form of overcast to broken mid and high
level clouds are observed streaming northeastward from
northeastern S America to within 300 nm either side of a line
from 05N51W to 13N37W to 17N28W to 18N23W where the moisture thins
out allowing for the clouds to transition to mainly scattered high
clouds to inland the coast of Africa at 19N16W. This area of
moisture and clouds are driven by a rather jet stream branch that
is along the southeast sector of the upper level trough described
above. Scattered moderate convection is along and just inland the
coast of S America between 43W-47W. Isolated showers are possible
elsewhere from 02N-11N between 41W-51W, and also from 10N-19N
between 30W-41W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 02/17/2018 - 18:03

000
AXNT20 KNHC 180003
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
703 PM EST Sat Feb 17 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient,
that exists between surface high pressure in the western Atlantic
Ocean, and lower surface pressure in northern sections of South
America, should continue to support winds pulsing to minimal
gale-force near the coast of Colombia through early next week.
The resultant wave heights with the gale force NE to E winds are
forecast to range from 12 to 16 feet, building to 12 to 18 ft Mon.
Please read the latest NHC High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the southern coastal
sections of Liberia near 05N08W southwestward to 03N14W and
dips to 01N18W, where it dips to below the Equator as the ITCZ
axis to 02S28W and to the coast of Brazil near 04S38W. Numerous
strong convection is well S of the coast of Africa and monsoon
trough from 01S to 04N between the prime meridian and 05W.
Scattered moderate convection is within 30 nm of line from 01N27W
to 01N31W to 02N35W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from an Atlantic Ocean 1026 mb high
pressure center located near 27N66W, to central Florida, to
26N90W in the Gulf of Mexico, to the western gulf near 25N95W.
The ridge will continue to maintain mainly gentle to moderate
southeast winds in the western Gulf, and light to gentle east to
southeast elsewhere through Sun night with the exception of
moderate winds in the SE waters and the Straits of Florida. Areas
of dense fog producing reduced visibility to below 1 nm are again
expected to form tonight mainly N of 27N and persist into Sun
afternoon in some locations. Isolated showers are over some
portions of the eastern gulf and far SE waters near the Straits of
Florida. Expect increasing winds and building seas by early next
week as high pressure strengthens in the western Atlantic Ocean. A
thermal trough will develop in the western Yucatan Peninsula
during each afternoon. The trough will drift westward across the
eastern Bay of Campeche during the overnight hours, and then
dissipate in the SW Gulf waters by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Patches of broken to at times overcast low clouds with isolated
showers are quickly moving westward across the western and central
Caribbean N of about 14N, and also over portions of the eastern
Caribbean.

A tight pressure gradient between a high pressure system that is
in the western Atlantic Ocean, and lower pressure in northern
sections of South America, will continue to support pulsing winds
of minimal gale force near the coast of Colombia through early
next week. Fresh to locally strong trade winds are expected
elsewhere across the Caribbean Sea. The high pressure will be
reinforced by a stronger high pressure system on Mon. The stronger
system will bring increasing winds and building seas across the
eastern and central Caribbean Sea, and the Tropical N Atlantic
waters possibly into the middle of next week.

ATLANTIC OCEAN...

An upper level trough extends from a 25N45W cyclonic circulation
center, to 17N50W, to 13N61W in the SE Caribbean Sea. A surface
trough extends from 31N50W to 26N59W, and another one extends
from near 31N45W to 24N45W 26N47W. A second surface trough is
along 45W from 24N to 31N. Isolated showers and thunderstorms
are noted near the second trough from 20N to 26N between 40W and
45W.

Broad surface anticyclonic wind flow covers the Atlantic Ocean
to the N of 17N and to the W of 50W. A 1026 mb high pressure
center is near 27N66W.

An E to W ridge along 27N, will shift gradually N to be along 28N
tonight, and then retract eastward, allowing a weak cold front to
move off the southeast United States on Sun. The front will stall
quickly and dissipate across the NW waters on Mon. Gentle to
moderate winds will prevail north of the ridge, with moderate
to fresh winds expected generally south of 25N, except becoming
strong along the north coast of Hispaniola and the northern
approach to the Windward Passage each evening. The ridge will be
reinforced by a stronger high pressure system on Monday.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT/Aguirre
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 13:37
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Feb 17 2018 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN NEW MEXICO NORTHEASTWARD TO WESTERN KANSAS... Confidence is a bit higher in a corridor of critical conditions developing from northeastern New Mexico into portions of western Kansas D2/Sun afternoon. Areas of 20-30 mph southwesterly winds will combine with 7-15% RH values amidst dry fuels for critical conditions within the delineated area. Surrounding the critical area, uncertainty regarding minimum RH values precludes any upgrade at this time, although elevated conditions remain likely especially away from deeper boundary layer moisture (expected over west Texas and vicinity). Observational trends will need to be monitored for potential of mixing of the dryline in central Kansas farther east than currently depicted, which may result in higher fire weather danger in that area. See the previous discussion for more information. ..Cook.. 02/17/2018 .PREV DISCUSSION... /ISSUED 0200 AM CST Sat Feb 17 2018/ ...Synopsis... The upper pattern over the CONUS will amplify on Day 2/Sunday as an upper trough develops over the western states. Mid-level southwesterly flow should strengthen into generally the 45-60 kt range over the southern/central High Plains Sunday afternoon. A surface low is forecast to form over eastern CO and then advance eastward across KS/NE through the period. Lee troughing will extend southward from this low across the southern/central High Plains. An area of high pressure initially centered over the OH/TN Valleys will shift eastward to the western Atlantic by Sunday evening. ...Portions of the Southern/Central High Plains... An enhanced surface pressure gradient will exist across parts of the southern/central High Plains on Day 2/Sunday between the eastern CO low and high pressure over the OH/TN Valleys. In addition, the strong mid-level winds mentioned above will likely reach the surface Sunday afternoon as the boundary layer becomes well mixed. Both of these features will contribute to strong/gusty southwesterly surface winds of 15-30 mph across parts of eastern NM/CO, western KS, and the TX/OK Panhandles. Higher gusts to 40-45 mph appear likely. The limiting factor precluding the introduction of a critical area for now remains uncertainty regarding the reduction of RH values across this region Sunday afternoon. Most short-term guidance suggests low-level moisture will be increasing across the southern High Plains through the day, which may tend to limit the degree of lowered RH values, especially with southward extent into east-central NM and parts of the TX Panhandle. Still, there is enough agreement amongst model guidance to support an elevated delineation where RH values should become lowered at least into the 15-20% range for a few hours. The best potential for locally critical conditions appears to be across parts of southeastern CO into far northeastern NM, the far western OK Panhandle, and a small portion of western KS. An upgrade to critical may be needed in a later update if confidence increases in RH values of 10-15% occurring for at least three hours across this area. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 13:37
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sat Feb 17 2018 Valid 181200Z - 191200Z ...CRITICAL FIRE WEATHER AREA FOR NORTHEASTERN NEW MEXICO NORTHEASTWARD TO WESTERN KANSAS... Confidence is a bit higher in a corridor of critical conditions developing from northeastern New Mexico into portions of western Kansas D2/Sun afternoon. Areas of 20-30 mph southwesterly winds will combine with 7-15% RH values amidst dry fuels for critical conditions within the delineated area. Surrounding the critical area, uncertainty regarding minimum RH values precludes any upgrade at this time, although elevated conditions remain likely especially away from deeper boundary layer moisture (expected over west Texas and vicinity). Observational trends will need to be monitored for potential of mixing of the dryline in central Kansas farther east than currently depicted, which may result in higher fire weather danger in that area. See the previous discussion for more information. ..Cook.. 02/17/2018 .PREV DISCUSSION... /ISSUED 0200 AM CST Sat Feb 17 2018/ ...Synopsis... The upper pattern over the CONUS will amplify on Day 2/Sunday as an upper trough develops over the western states. Mid-level southwesterly flow should strengthen into generally the 45-60 kt range over the southern/central High Plains Sunday afternoon. A surface low is forecast to form over eastern CO and then advance eastward across KS/NE through the period. Lee troughing will extend southward from this low across the southern/central High Plains. An area of high pressure initially centered over the OH/TN Valleys will shift eastward to the western Atlantic by Sunday evening. ...Portions of the Southern/Central High Plains... An enhanced surface pressure gradient will exist across parts of the southern/central High Plains on Day 2/Sunday between the eastern CO low and high pressure over the OH/TN Valleys. In addition, the strong mid-level winds mentioned above will likely reach the surface Sunday afternoon as the boundary layer becomes well mixed. Both of these features will contribute to strong/gusty southwesterly surface winds of 15-30 mph across parts of eastern NM/CO, western KS, and the TX/OK Panhandles. Higher gusts to 40-45 mph appear likely. The limiting factor precluding the introduction of a critical area for now remains uncertainty regarding the reduction of RH values across this region Sunday afternoon. Most short-term guidance suggests low-level moisture will be increasing across the southern High Plains through the day, which may tend to limit the degree of lowered RH values, especially with southward extent into east-central NM and parts of the TX Panhandle. Still, there is enough agreement amongst model guidance to support an elevated delineation where RH values should become lowered at least into the 15-20% range for a few hours. The best potential for locally critical conditions appears to be across parts of southeastern CO into far northeastern NM, the far western OK Panhandle, and a small portion of western KS. An upgrade to critical may be needed in a later update if confidence increases in RH values of 10-15% occurring for at least three hours across this area. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 02/17/2018 - 11:29

000
AXNT20 KNHC 171729
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1229 PM EST Sat Feb 17 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient,
that exists between surface high pressure in the western Atlantic
Ocean, and lower surface pressure in northern sections of South
America, should continue to support winds pulsing to minimal
gale-force near the coast of Colombia through Sunday. The
resultant wave heights with the gale-force winds are forecast to
range from 10 feet to 15 feet. Please read the latest NHC High
Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for
more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the southern coastal sections
of Liberia near 05N08W, to the Equator along 18W. The ITCZ
continues from the Equator along 18W, to 02S28W, to 04S33W, and
to the coast of Brazil near 04S38W. Precipitation: scattered to
numerous strong rainshowers are from 04N southward between the
Prime Meridian and 01W. widely scattered moderate to isolated
strong from 01N to 03N between 08W and 11W. isolated moderate to
locally strong rainshowers are elsewhere from 10N southward.
Upper level SW wind flow is to the SE of the line that passes
through 24N16W 21N40W, to 16N50W and to 14N63W in the Caribbean
Sea.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from an Atlantic Ocean 1026 mb high
pressure center that is near 27N66W, to central Florida, to 26N90W
in the Gulf of Mexico, to 21N98W in interior sections of Mexico.

A ridge will dominate the Gulf region this weekend producing
mainly gentle-to-moderate winds in the western Gulf, and light-
to-gentle winds in the eastern Gulf, with the exception of
moderate winds in the SE waters and the Straits of Florida.
Expect increasing winds and building seas by early next week as
high pressure strengthens in the western Atlantic Ocean. A
thermal trough will develop in the western Yucatan Peninsula
during each afternoon. The trough will drift westward across the
eastern Bay of Campeche during the overnight hours, and then
dissipate in the southwest Gulf waters by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Rainshowers are possible, in areas of broken-to-overcast low
level clouds, across the entire area. 24-hour rainfall totals that
are listed for the period that ended at 17/1200 UTC...according
to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...
MIATPTPAN/SXCA01 KNHC...are: 0.39 in St. Thomas in the U.S. Virgin
Islands, 0.18 in San Juan in Puerto Rico, 0.07 in Montego Bay in
Jamaica, and 0.03 in Guadeloupe.

A tight pressure gradient between a high pressure system that is
in the western Atlantic Ocean, and lower pressure in northern
sections of South America, will continue to support pulsing winds
of minimal gale-force near the coast of Colombia through the
forecast period. Fresh to locally strong trade winds are expected
elsewhere across the Caribbean Sea. The high pressure will be
reinforced by a stronger system on Monday. The stronger system
will bring increasing winds and building seas across the eastern
and central Caribbean Sea, and the Tropical N Atlantic waters from
Monday through Wednesday.

ATLANTIC OCEAN...

An upper level trough extends from a 25N45W cyclonic circulation
center, to 17N50W, to 13N61W in the SE Caribbean Sea. One surface
trough is along 31N31W 29N38W 28N45W 26N47W. A second surface
trough is along 26N45W 23N44W 20N44W. isolated moderate to locally
strong rainshowers are from 22N to 30N between 38W and 46W.

Broad surface anticyclonic wind flow covers the Atlantic Ocean
from 17N northward from 50W westward. A 1026 mb high pressure
center is near 27N66W.

An Atlantic Ocean ridge, E-to-W along 27N, will shift gradually N
to be along 28N tonight, and then retract eastward, allowing a
weak cold front to move off the southeast United States on Sunday.
The front will stall quickly and dissipate across the
northwestern waters on Monday. Gentle-to-moderate winds will
prevail north of the ridge, with moderate-to-fresh winds expected
generally south of 25N, except becoming strong along the north
coast of Hispaniola and the northern approach to the Windward
Passage each evening. The ridge will be reinforced by a stronger
high pressure system on Monday.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 09:40
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0939 AM CST Sat Feb 17 2018 Valid 171700Z - 181200Z The ongoing forecast is on track with no changes needed. Elevated fire weather conditions remain likely in a large part of Kansas and extreme northwest Oklahoma. See the previous discussion below for more details. ..Cook.. 02/17/2018 .PREV DISCUSSION... /ISSUED 0154 AM CST Sat Feb 17 2018/ ...Synopsis... A shortwave trough over the High Plains evident on water vapor satellite imagery early this morning will move eastward to the Great Lakes and OH Valley by this evening. An upstream shortwave trough should move across the Pacific Northwest and northern Rockies from this evening through the end of the period. Surface high pressure centered over the eastern CONUS will develop eastward off the East Coast, while lee troughing forms over the High Plains. A separate surface trough/front associated with the shortwave trough over the Plains should move southward across KS into parts of northern OK this afternoon. ...Portions of the Southern/Central Plains... Strong/gusty northwesterly winds around 15-20 mph, locally higher, will develop later this morning and afternoon across parts of KS into northern OK behind a surface trough/front. Although temperatures should not warm substantially due to some low-level cold air advection, an antecedent dry airmass and diurnal mixing of the boundary layer will likely support RH values falling into the 15-25% range for a few hours through peak heating. Dry/dormant fuels remain in place across most of this region, and the forecast meteorological conditions support the continuation of an elevated area for parts of KS into northern OK. The southern extent of the elevated area (in northern OK) has been trimmed slightly due to ongoing light to moderate rainfall associated with a southern-stream shortwave trough. The lack of an even warmer/drier low-level airmass across this region precludes a critical delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 09:40
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0939 AM CST Sat Feb 17 2018 Valid 171700Z - 181200Z The ongoing forecast is on track with no changes needed. Elevated fire weather conditions remain likely in a large part of Kansas and extreme northwest Oklahoma. See the previous discussion below for more details. ..Cook.. 02/17/2018 .PREV DISCUSSION... /ISSUED 0154 AM CST Sat Feb 17 2018/ ...Synopsis... A shortwave trough over the High Plains evident on water vapor satellite imagery early this morning will move eastward to the Great Lakes and OH Valley by this evening. An upstream shortwave trough should move across the Pacific Northwest and northern Rockies from this evening through the end of the period. Surface high pressure centered over the eastern CONUS will develop eastward off the East Coast, while lee troughing forms over the High Plains. A separate surface trough/front associated with the shortwave trough over the Plains should move southward across KS into parts of northern OK this afternoon. ...Portions of the Southern/Central Plains... Strong/gusty northwesterly winds around 15-20 mph, locally higher, will develop later this morning and afternoon across parts of KS into northern OK behind a surface trough/front. Although temperatures should not warm substantially due to some low-level cold air advection, an antecedent dry airmass and diurnal mixing of the boundary layer will likely support RH values falling into the 15-25% range for a few hours through peak heating. Dry/dormant fuels remain in place across most of this region, and the forecast meteorological conditions support the continuation of an elevated area for parts of KS into northern OK. The southern extent of the elevated area (in northern OK) has been trimmed slightly due to ongoing light to moderate rainfall associated with a southern-stream shortwave trough. The lack of an even warmer/drier low-level airmass across this region precludes a critical delineation. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 02/17/2018 - 06:07

000
AXNT20 KNHC 171206
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
706 AM EST Sat Feb 17 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
1130 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient,
that exists between surface high pressure in the western Atlantic
Ocean, and lower surface pressure in northern sections of South
America, should continue to support winds pulsing to minimal
gale-force near the coast of Colombia through Sunday. The
resultant wave heights with the gale-force winds are forecast to
range from 10 to 14 feet. Please read the latest NHC High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through coastal border sections of
Sierra Leone and near Liberia near 07N11W, to the Equator along
21W. The ITCZ continues from the Equator along 21W, to 01S30W, to
02S38W, and to the coast of Brazil near 03S31W. Precipitation:
isolated moderate to locally strong rainshowers from 10N
southward. Upper level SW wind flow is to the SE of the line that
passes through 22N17W 20N40W, to 15N65W in the Caribbean Sea.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends from the Atlantic Ocean near 27N75W,
to a 1022 mb high pressure center that is near 27N83W along the
Florida west coast, southwestward to Mexico near 20N97W.

Weak high pressure will persist across the E Gulf through Saturday,
when a weak cold front will stall E to W across the northern and
northwest waters. The cold front will retreat northwestward on
Sunday night into Monday. Locally dense fog will linger north of
27N west of 91W through the morning hours. A thermal trough will
develop in the western Yucatan Peninsula during each afternoon,
drift westward across the eastern Bay of Campeche during the
overnight hours, and then dissipate in the southwestern corner of
the Gulf of Mexico by late each morning.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Rainshowers are possible, in areas of broken-to-overcast low
level clouds, across the entire area. 24-hour rainfall totals that
are listed for the period that ended at 15/1200 UTC...according
to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...
MIATPTPAN/SXCA01 KNHC...are: 0.09 in Guadeloupe.

An Atlantic Ocean ridge, extending E-to-W along 27N-28N, will
maintain strong-to near gale-force trade winds across the central
and southwestern Caribbean Sea through the weekend, with nocturnal
gale-force wind conditions along the northwestern coast of
Colombia. Fresh-to-locally strong trade winds are expected
elsewhere across the Caribbean Sea. Strong high pressure across
the NW Atlantic Ocean will build S across the region from Sunday
night through Wednesday, to produce strong trade winds across the
eastern Caribbean Sea and the tropical Atlantic Ocean.

ATLANTIC OCEAN...

An upper level trough extends from a 25N45W cyclonic circulation
center, to 17N50W, to 13N61W in the SE Caribbean Sea. Widely
scattered to scattered moderate and isolated strong rainshowers
are from 24N to 30N between 40W and 45W.

An Atlantic Ocean ridge, E-to-W along 27N, will shift gradually N
to along 28N on Saturday night, and then retract eastward,
allowing a weak cold front to move off the southeast United States
on Sunday. The front will stall quickly and dissipate across the
northwestern waters on Monday. Gentle-to- moderate winds will
prevail north of the ridge, with moderate-to- fresh winds expected
generally south of 25N, except becoming strong along the north
coast of Hispaniola and the northern approach to the Windward
Passage each evening.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 02:01
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sat Feb 17 2018 Valid 181200Z - 191200Z ...Synopsis... The upper pattern over the CONUS will amplify on Day 2/Sunday as an upper trough develops over the western states. Mid-level southwesterly flow should strengthen into generally the 45-60 kt range over the southern/central High Plains Sunday afternoon. A surface low is forecast to form over eastern CO and then advance eastward across KS/NE through the period. Lee troughing will extend southward from this low across the southern/central High Plains. An area of high pressure initially centered over the OH/TN Valleys will shift eastward to the western Atlantic by Sunday evening. ...Portions of the Southern/Central High Plains... An enhanced surface pressure gradient will exist across parts of the southern/central High Plains on Day 2/Sunday between the eastern CO low and high pressure over the OH/TN Valleys. In addition, the strong mid-level winds mentioned above will likely reach the surface Sunday afternoon as the boundary layer becomes well mixed. Both of these features will contribute to strong/gusty southwesterly surface winds of 15-30 mph across parts of eastern NM/CO, western KS, and the TX/OK Panhandles. Higher gusts to 40-45 mph appear likely. The limiting factor precluding the introduction of a critical area for now remains uncertainty regarding the reduction of RH values across this region Sunday afternoon. Most short-term guidance suggests low-level moisture will be increasing across the southern High Plains through the day, which may tend to limit the degree of lowered RH values, especially with southward extent into east-central NM and parts of the TX Panhandle. Still, there is enough agreement amongst model guidance to support an elevated delineation where RH values should become lowered at least into the 15-20% range for a few hours. The best potential for locally critical conditions appears to be across parts of southeastern CO into far northeastern NM, the far western OK Panhandle, and a small portion of western KS. An upgrade to critical may be needed in a later update if confidence increases in RH values of 10-15% occurring for at least three hours across this area. ..Gleason.. 02/17/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 02:01
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sat Feb 17 2018 Valid 181200Z - 191200Z ...Synopsis... The upper pattern over the CONUS will amplify on Day 2/Sunday as an upper trough develops over the western states. Mid-level southwesterly flow should strengthen into generally the 45-60 kt range over the southern/central High Plains Sunday afternoon. A surface low is forecast to form over eastern CO and then advance eastward across KS/NE through the period. Lee troughing will extend southward from this low across the southern/central High Plains. An area of high pressure initially centered over the OH/TN Valleys will shift eastward to the western Atlantic by Sunday evening. ...Portions of the Southern/Central High Plains... An enhanced surface pressure gradient will exist across parts of the southern/central High Plains on Day 2/Sunday between the eastern CO low and high pressure over the OH/TN Valleys. In addition, the strong mid-level winds mentioned above will likely reach the surface Sunday afternoon as the boundary layer becomes well mixed. Both of these features will contribute to strong/gusty southwesterly surface winds of 15-30 mph across parts of eastern NM/CO, western KS, and the TX/OK Panhandles. Higher gusts to 40-45 mph appear likely. The limiting factor precluding the introduction of a critical area for now remains uncertainty regarding the reduction of RH values across this region Sunday afternoon. Most short-term guidance suggests low-level moisture will be increasing across the southern High Plains through the day, which may tend to limit the degree of lowered RH values, especially with southward extent into east-central NM and parts of the TX Panhandle. Still, there is enough agreement amongst model guidance to support an elevated delineation where RH values should become lowered at least into the 15-20% range for a few hours. The best potential for locally critical conditions appears to be across parts of southeastern CO into far northeastern NM, the far western OK Panhandle, and a small portion of western KS. An upgrade to critical may be needed in a later update if confidence increases in RH values of 10-15% occurring for at least three hours across this area. ..Gleason.. 02/17/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 02/17/2018 - 01:55
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CST Sat Feb 17 2018 Valid 171200Z - 181200Z ...Synopsis... A shortwave trough over the High Plains evident on water vapor satellite imagery early this morning will move eastward to the Great Lakes and OH Valley by this evening. An upstream shortwave trough should move across the Pacific Northwest and northern Rockies from this evening through the end of the period. Surface high pressure centered over the eastern CONUS will develop eastward off the East Coast, while lee troughing forms over the High Plains. A separate surface trough/front associated with the shortwave trough over the Plains should move southward across KS into parts of northern OK this afternoon. ...Portions of the Southern/Central Plains... Strong/gusty northwesterly winds around 15-20 mph, locally higher, will develop later this morning and afternoon across parts of KS into northern OK behind a surface trough/front. Although temperatures should not warm substantially due to some low-level cold air advection, an antecedent dry airmass and diurnal mixing of the boundary layer will likely support RH values falling into the 15-25% range for a few hours through peak heating. Dry/dormant fuels remain in place across most of this region, and the forecast meteorological conditions support the continuation of an elevated area for parts of KS into northern OK. The southern extent of the elevated area (in northern OK) has been trimmed slightly due to ongoing light to moderate rainfall associated with a southern-stream shortwave trough. The lack of an even warmer/drier low-level airmass across this region precludes a critical delineation. ..Gleason.. 02/17/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 02/17/2018 - 00:05

000
AXNT20 KNHC 170605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
104 AM EST Sat Feb 17 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0545 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
between a high pressure system over the western Atlantic and
lower pressure over northern South America should continue to
support winds pulsing to minimal gale-force near the coast of
Colombia through Sun. The resultant waveheights with the gale
force winds are forecast to range from 10 to 14 feet. Please read
the latest NHC High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the eastern Atlantic near 07N12W
and continues to 01N20W, where latest scatterometer data
indicates the ITCZ begins and dips to S of the Equator at 23W.
Scattered moderate isolated strong convection is within 120 nm S
of the axis between 20W-23W. Scattered moderate convection is
S of the axis within 30 nm of 02N14W, and also N of the axis
within 30 nm of line from 02N25W to 03N30W to 04N34W.

...DISCUSSION...

GULF OF MEXICO...

The western extension of Atlantic high pressure across the area
is maintaining pretty tranquil weather conditions throughout the
basin. At the surface, a 1022 mb high center is analyzed at
27N88W. In addition, satellite water vapor imagery depicts
abundant dry air in the mid and upper-levels of the atmosphere.
Surface observations and scatterometer data indicate that the
winds are light and generally southeast or southerly across much
of the area. Observed waveheights are in the 3 to 5 ft range
throughout, and little change is expected through Sun. A weak
surface trough extends from northern Florida southwestward to
over the far NE Gulf at 29N84W and to near 27.5N87W. Only
isolated showers are near this trough. Other isolated showers
are noted over some portions of the far SE waters of the gulf.
Areas of dense fog are expected over portions of the gulf mainly N
of about 27N during the morning hours producing sharply reduced
visibilities. Little change in the present synoptic pattern is
expected through Sun, however, winds and seas are forecast to
increase by early next week when high pressure strengthens over
the western Atlantic.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details regarding
the Gale Warning near the coast of Colombia.

Only patches of clouds and embedded quick moving isolated showers
are seen across the Caribbean within patches of low-level
moisture. The trade winds in the area are fresh to strong, and
they are even stronger near the coast of Colombia as discussed
above. These winds are occurring due to the tight pressure
gradient between a 1025 mb high over the western Atlantic and the
typical lower pressures found over northern S America. No
significant changes are expected to occur today, however, winds
and seas will likely increase over the eastern and central
Caribbean on Sun and into early next week due to a tighter
pressure gradient attributed to stronger high pressure forecast to
build N of the area.

ATLANTIC OCEAN...

Tranquil conditions and fairly light winds are occurring across
the western Atlantic supported by a surface ridge and dry and
stable air aloft. Over the central Atlantic, an upper-level low
and accompanying surface trough is producing scattered showers and
isolated thunderstorms from 25N-28N between 42W-45W. Scattered
moderate convection, decreasing in coverage, is observed over the
deep tropics from 03N-09N between 43W-48W as this activity developed
from low-level convergence in that area. The activity is being
further aided aloft by a nearby upper jet stream branch. No
significant weather is occurring over the eastern Atlantic as
atmospheric conditions are rather stable. Isolated to scattered
showers moving quickly westward are present S of 25N W of 59W.
This activity is affecting the Lesser Antilles, Puerto Rico
and immediate surrounding islands. A steady stream of mid and
upper level moisture in the form of broken mid and upper level
clouds is seen streaming northeastward from northeastern S America
to within 220 nm either side of line from 05N50W to 11N37W to
14N26W and to inland the African coast at 17N16W. Isolated showers
are possible elsewhere from 02N-10N between 40W and the coast of
S America, and also from 10N-18N between 20W-35W.


For additional information please visit
http://www.hurricanes.gov/marine

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 02/16/2018 - 22:33

000
AXNT20 KNHC 170433 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
704 PM EST Fri Feb 16 2018

Correceted Gulf of Mexico

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
between a high pressure system over the western Atlantic and
lower pressure over northern South America should continue to
support winds pulsing to minimal gale-force near the coast of
Colombia through Sun. The resultant with the gale force winds
are forecast to range from 10 to 14 feet. Please read the latest
NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the eastern Atlantic near 07N12W
and continues to 01N19W, where latest scatterometer data
indicates the ITCZ begins and dips to S of the Equator at 23W.
Scattered moderate isolated strong convection is within 180 nm
S of the axis between 12W-15W. Scattered moderate convection is
within 60 nm S of the axis between 20W-23W, and also N of the
axis within 30 nm of line from 02N24W to 03N28W.

...DISCUSSION...

GULF OF MEXICO...Corrected

The western extension of Atlantic high pressure across the area
is maintaining pretty tranquil weather conditions throughout the
basin. In addition, satellite water vapor imagery depicts
abundant dry air in the mid and upper-levels of the atmosphere.
Surface observations and scatterometer data indicate that the
winds are light and generally southeast or southerly across much
of the area. Observed waveheights are in the 3 to 5 ft range
throughout, and little change is expected through Sun. A weak
surface trough extends into the NE Gulf from the Florida
panhandle along a position from near 30N85W southwestward to
near 27N87W. Only isolated showers are near this trough. Areas
of dense fog are expected over portions of gulf mainly N of
about 27N tonight into Sat producing sharply reduced
visibilities. Little change in the present synoptic pattern is
expected through Sun, however, winds and seas are forecast to
increase by early next week when high pressure strengthens over
the western Atlantic.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details about the
Gale Warning near the coast of Colombia.

Only patches of clouds and embedded quick-moving isolated showers
are seen across the Caribbean Sea today. The trade winds in the
area are fresh to strong, and they are even stronger near the
coast of Colombia as discussed above. These winds are occurring
due to the tight pressure gradient between a 1024 mb high over
the western Atlantic and the typical lower pressures found over
northern South America. No significant changes are expected to
occur on Saturday, but winds and seas will likely increase over
the eastern and central Caribbean on Sun and early next week when
the gradient tightens from stronger high pressure that builds to
the N of the area.

ATLANTIC OCEAN...

Tranquil conditions and fairly light winds are occurring across
the western Atlantic supported by a surface ridge and dry and
stable air aloft. Over the central Atlantic, an upper-level low
and accompanying surface trough is producing scattered moderate
convection from 28N-32N between 41W- 45W. Scattered moderate
isolated strong convection is noted over the deep tropics from
2N-6N between 43W-50W in association with a surface trough and
diffluent flow aloft. No significant weather is occurring over
the eastern Atlantic, but earlier scatterometer data indicated
that the trade wind flow is fresh to strong south of about 20N.

For additional information please visit
http://www.hurricanes.gov/marine

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 02/16/2018 - 22:19

000
AXNT20 KNHC 170419 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
704 PM EST Fri Feb 16 2018

Correceted Gulf of Mexico

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
between a high pressure system over the western Atlantic and
lower pressure over northern South America should continue to
support winds pulsing to minimal gale-force near the coast of
Colombia through Sun. The resultant with the gale force winds
are forecast to range from 10 to 14 feet. Please read the latest
NHC High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the eastern Atlantic near 07N12W
and continues to 01N19W, where latest scatterometer data
indicates the ITCZ begins and dips to S of the Equator at 23W.
Scattered moderate isolated strong convection is within 180 nm
S of the axis between 12W-15W. Scattered moderate convection is
within 60 nm S of the axis between 20W-23W, and also N of the
axis within 30 nm of line from 02N24W to 03N28W.

...DISCUSSION...

GULF OF MEXICO...Corrected

The western extension of Atlantic high pressure across the area
is maintaining pretty tranquil weather conditions throughout the
basin. In addition, satellite water vapor imagery depicts
abundant dry air in the mid and upper-levels of the atmosphere.
Surface observations and scatterometer data indicate that the
winds are light and generally southeast or southerly across much
of the area. Observed waveheights are in the 3 to 5 ft range
throughout, and little change is expected through Sun. A weak
surface trough extends into the NE Gulf from the Florida
panhandle along a position from near 30N85W southwestward to
near 27N87W. Only isolated showers are near this trough. Areas
of dense fog are expected over portions of gulf mainly N of
about 27N tonight into Sat producing sharply reduced
visibilities. Little change in the present synoptic pattern is
expected through Sun, however, winds and seas are forecast to
increase by early next week when high pressure strengthens over
the western Atlantic.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section for details about the
Gale Warning near the coast of Colombia.

Only patches of clouds and embedded quick-moving isolated showers
are seen across the Caribbean Sea today. The trade winds in the
area are fresh to strong, and they are even stronger near the
coast of Colombia as discussed above. These winds are occurring
due to the tight pressure gradient between a 1024 mb high over
the western Atlantic and the typical lower pressures found over
northern South America. No significant changes are expected to
occur on Saturday, but winds and seas will likely increase over
the eastern and central Caribbean on Sun and early next week when
the gradient tightens from stronger high pressure that builds to
the N of the area.

ATLANTIC OCEAN...

Tranquil conditions and fairly light winds are occurring across
the western Atlantic supported by a surface ridge and dry and
stable air aloft. Over the central Atlantic, an upper-level low
and accompanying surface trough is producing scattered moderate
convection from 28N-32N between 41W- 45W. Scattered moderate
isolated strong is noted over the deep tropics from 2N-6N between
43W-50W in association with a surface trough and diffluent flow
aloft. No significant weather is occurring over the eastern
Atlantic, but earlier scatterometer data indicated that the trade
wind flow is fresh to strong south of about 20N.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT/Aguirre
Categories: Weather

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