Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/20/2018 - 05:48

000
AXNT20 KNHC 201147
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
647 AM EST Tue Feb 20 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 high pressure in the western Atlantic and
lower pressure in northern sections of South America. This
pattern will support winds pulsing to minimal gale-force near
the coast of Colombia each night this week. Wave heights within
the area of 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 coast of Africa near
07N12W southwestward to 01N20W. The ITCZ crosses the equator
near 21W and remains south of the discussion area to the coast
of South America. Scattered moderate convection is from 00N-05N
between 11W-30W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward across the entire basin from
the Atlantic. Scatterometer data depicts moderate southeasterly
winds across most of the area. Satellite imagery shows isolated
shallow convection in the SE Gulf and fair weather elsewhere.
Expect increasing winds and building seas through Wed as high
pressure strengthens in the western Atlantic. A thermal trough
will develop over the western Yucatan Peninsula each evening
through mid week, drift westward across the Bay of Campeche
during overnight hours, then dissipate in the SW Gulf by late
morning.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section for details about
a Gale Warning in effect near the coast of Colombia.

A tight pressure gradient across the basin created by the
combination of strong high pressure over the Atlantic and lower
pressure over NW Colombia is producing strong east winds between
70W-80W, while moderate to fresh winds prevail elsewhere. Trade
wind showers are evident from satellite imagery primarily east
of 70W. The high pressure will strengthen through Wednesday,
increasing the winds and building seas east of 80W in the
Caribbean and the Tropical N Atlantic waters through mid-week.

ATLANTIC OCEAN...

A cold front extending from 32N40W to 28N48W to 27N56W becomes
diffuse west of 60W. Scattered moderate showers are observed
along a pre-frontal trough, and low clouds with scattered light
rain are evident along the frontal boundary. Broad high pressure
centered north of 30N prevails across the rest of the basin. The
front will become stationary during the next 12 hours and should
dissipate later today. The existing area of high pressure will
be fortified by a stronger subtropical high through mid-week.

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

$$

Mundell/ERA

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/20/2018 - 01:30
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0129 AM CST Tue Feb 20 2018 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... An upper-level shortwave trough is forecast to move along the California coast on Wednesday morning and into the Southwest by Wednesday evening to reinforce the western U.S. trough, supporting continued southwesterly flow aloft over the central CONUS. In the wake of surface cold frontal passage across the plains, high pressure will move eastward toward the Mississippi Valley. Overall, the lack of strong winds and relatively cool/moist conditions over much of the CONUS will limit fire weather concerns on Wednesday. ..Jirak.. 02/20/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/20/2018 - 01:29
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0128 AM CST Tue Feb 20 2018 Valid 201200Z - 211200Z ...Synopsis... An upper-level trough will weaken over the West today as a midlevel speed max ejects downstream toward the upper Mississippi Valley. At the surface, a low pressure system near the Great Lakes will lift northeastward while an associated cold front slowly advances southeastward across the middle Mississippi Valley. Farther southwest, a dryline will sharpen from northern Texas to the Big Bend region. ...Portions of the Southern High Plains... Despite weakening flow aloft throughout the day, sufficient flow will linger to support sustained afternoon surface winds of 15-20 mph across much of the region. Westerly downslope flow (west of the dryline and ahead of the advancing cold front) will also support warming/drying at the surface, leading to RH values falling to near 20%. These meteorological conditions will support elevated fire weather concerns given the ongoing drought and dry fuels. ..Jirak.. 02/20/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/20/2018 - 00:05

000
AXNT20 KNHC 200605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 AM EST Tue Feb 20 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
continues between high pressure in the western Atlantic and
lower pressure in northern sections of South America. This
pattern will support winds pulsing to minimal gale-force near
the coast of Colombia each night this week. Wave heights within
the area of 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 coast of Africa near
07N12W southwestward to 01N20W. The ITCZ crosses the equator
near 21W and remains south of the discussion area to the coast
of South America. Scattered moderate convection is from 00N-05N
between 11W-30W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward across the entire basin from
the Atlantic. Scatterometer data depicts moderate southeasterly
winds across most of the area. Satellite imagery shows isolated
shallow convection in the SE Gulf and fair weather elsewhere.
Expect increasing winds and building seas through Wed as high
pressure strengthens in the western Atlantic. A thermal trough
will develop over the western Yucatan Peninsula each evening
through mid week, drift westward across the Bay of Campeche
during overnight hours, then dissipate in the SW Gulf by late
morning.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section for details about
a Gale Warning in effect near the coast of Colombia.

A tight pressure gradient across the basin created by the
combination of strong high pressure over the Atlantic and lower
pressure over NW Colombia is producing strong east winds between
70W-80W, while moderate to fresh winds prevail elsewhere. Trade
wind showers are evident from satellite imagery primarily east
of 70W. The high pressure will strengthen through Wednesday,
increasing the winds and building seas east of 80W in the
Caribbean and the Tropical N Atlantic waters through mid-week.

ATLANTIC OCEAN...

A cold front extending from 32N40W to 28N48W to 27N56W becomes
diffuse west of 60W. Scattered moderate showers are observed
along a pre-frontal trough, and low clouds with scattered light
rain are evident along the frontal boundary. Broad high pressure
centered north of 30N prevails across the rest of the basin. The
front will become stationary during the next 12 hours and should
dissipate later today. The existing area of high pressure will
be fortified by a stronger subtropical high through mid-week.

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

$$

Mundell
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/19/2018 - 18:00

000
AXNT20 KNHC 200000
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 PM EST Mon Feb 19 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
2330 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
continues between high pressure in the western Atlantic and
lower pressure in northern sections of South America. This
pattern supports winds pulsing to minimal gale-force near the
coast of Colombia each night through the week. Wave heights
within the area of 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 coast of Africa near
08N13W southwestward to 02N18W. The ITCZ crosses the equator
near 21W and remains south of the discussion area to the coast
of South America. Scattered moderate convection is from 00N-04N
between 11W-30W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward across the entire basin from
the west Atlantic. Scatterometer data depicts gentle to moderate
southeasterly winds across the whole area. Satellite imagery
shows isolated shallow convection in the SE Gulf and mostly
clear weather elsewhere. Expect increasing winds and building
seas through Wed as high pressure strengthens in the western
Atlantic. A thermal trough will develop over the western Yucatan
Peninsula each evening through mid week, drift westward across
the Bay of Campeche during overnight hours, then dissipate in
the SW Gulf by late morning.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section for details about
a Gale Warning in effect near the coast of Colombia.

A tight pressure gradient across the basin created by the
combination of a high pressure over the Atlantic and lower
pressure over NW Colombia is producing strong east winds between
70W-80W, while moderate to fresh winds prevail elsewhere. The
high pressure will strengthen overnight into Wednesday, and
increase winds and build seas east of 80W in the Caribbean and
the Tropical N Atlantic waters through mid-week.

ATLANTIC OCEAN...

A broad area of high pressure centered north of 30N prevails
across the basin. A weakness in the ridge is noted as a surface
trough that extends from 31N43W to 26N50W. A cold front has
pushed southward to roughly along 29N between 50W-65W, then it
becomes stationary as it extends northwestward to coastal
Georgia at 31N80W. Scattered low clouds are observed along the
frontal boundary. The front will become stationary overnight and
dissipate early Tuesday. The existing area of high pressure will
be fortified by a stronger subtropical high through mid-week.

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

$$

Mundell
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 13:10
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0108 PM CST Mon Feb 19 2018 Valid 201200Z - 211200Z The Elevated fire weather area over the southern High Plains has been extended eastward into most of Northwest Texas, as the latest guidance suggests westerly/southwesterly sustained surface winds of 15-20 mph amidst RH values near 20%. Otherwise, only minor changes were needed, with some contraction to the Elevated area over eastern New Mexico where surface temperatures of less than 50F should temper the large-scale fire weather threat. See previous discussion below for more information. ..Elliott.. 02/19/2018 .PREV DISCUSSION... /ISSUED 0105 AM CST Mon Feb 19 2018/ ...Synopsis... An upper-level trough over the West will weaken on Tuesday as a midlevel speed max ejects downstream across the Upper Mississippi Valley. At the surface, a low pressure system will lift northeast toward the Great Lakes with an associated cold front slowly advancing southeastward over the plains. ...Portions of Southern High Plains... Although the wind speeds aloft will be weakening compared to previous days, sufficient flow will likely yield sustained afternoon surface wind speeds approaching 20 mph through boundary layer mixing processes. Downslope westerly flow will also support warming/drying at the surface, resulting in afternoon RH values below 20% despite relatively cool temperatures across the region (generally at or below 60F). Overall, these meteorological conditions support elevated fire weather conditions given the dry fuels across the region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 13:10
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0108 PM CST Mon Feb 19 2018 Valid 201200Z - 211200Z The Elevated fire weather area over the southern High Plains has been extended eastward into most of Northwest Texas, as the latest guidance suggests westerly/southwesterly sustained surface winds of 15-20 mph amidst RH values near 20%. Otherwise, only minor changes were needed, with some contraction to the Elevated area over eastern New Mexico where surface temperatures of less than 50F should temper the large-scale fire weather threat. See previous discussion below for more information. ..Elliott.. 02/19/2018 .PREV DISCUSSION... /ISSUED 0105 AM CST Mon Feb 19 2018/ ...Synopsis... An upper-level trough over the West will weaken on Tuesday as a midlevel speed max ejects downstream across the Upper Mississippi Valley. At the surface, a low pressure system will lift northeast toward the Great Lakes with an associated cold front slowly advancing southeastward over the plains. ...Portions of Southern High Plains... Although the wind speeds aloft will be weakening compared to previous days, sufficient flow will likely yield sustained afternoon surface wind speeds approaching 20 mph through boundary layer mixing processes. Downslope westerly flow will also support warming/drying at the surface, resulting in afternoon RH values below 20% despite relatively cool temperatures across the region (generally at or below 60F). Overall, these meteorological conditions support elevated fire weather conditions given the dry fuels across the region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/19/2018 - 11:28

000
AXNT20 KNHC 191728
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1228 PM EST Mon Feb 19 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
1715 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight surface pressure gradient
continues between a high pressure in the western Atlantic and
lower pressures in northern sections of South America. This
pattern supports winds pulsing to minimal gale-force near the
coast of Colombia every night/early morning hours through the
week. Wave heights within the area of 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 coast of Africa near
07N12W southwestward to 02N18W. The ITCZ continues from that
point to 03N40W. Scattered moderate convection is within 90 nm on
either side of the boundaries between 10W-39W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward from a 1037 mb high centered
over the west Atlantic and covers the whole basin. A thermal
trough is extending across the Bay of Campeche with little to no
convection. Scatterometer data depicts gentle to moderate
southeasterly winds across the whole area. These winds are
transporting enough low-level moisture to generate scattered
showers currently moving across the Straits of Florida while
isolated showers are noted east of 90W. Expect increasing winds
and building seas beginning today as high pressure strengthens in
the western Atlantic. The thermal trough will develop over the
western Yucatan Peninsula through mid week, drifting westward
across the eastern Bay of Campeche during the overnight hours, and
then dissipate in the SW Gulf waters by the late morning hours.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section for details
regarding the Gale Warning in effect for the area near the coast
of Colombia.

A tight pressure gradient across the basin created by the
combination of a high pressure over the Atlantic and lower
pressure over NW Colombia is producing strong east winds between
70W-80W, while moderate to fresh winds prevail elsewhere.
The high pressure will be reinforced by a stronger one later today.
The pressure gradient associated with this stronger high system
will bring increasing winds and building seas across the eastern
and central Caribbean, and the Tropical N Atlantic waters through
mid-week.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1024 mb high near 29N37W. A weakness in the ridge is noted as a
surface trough that extends from 30N44W to 27N51W. A cold front
has nudged southward to roughly along 30N between 50W-70W,
then it becomes stationary as it extends northwestward to coastal
Georgia at 31N79W. Minimal cloudiness is observed near the front.
The front will become stationary today and dissipate by early
Tuesday. The existing area of high pressure is forecast to be
fortified by stronger system through mid-week.

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

$$

ERA

Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 10:35
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1034 AM CST Mon Feb 19 2018 Valid 191700Z - 201200Z Relatively minor modifications were made to the Elevated fire weather area over the Southern High plains to account for the latest high-resolution guidance from the HRRR/HREF/RAP and observational data. Primary adjustments include a slight extension farther into western OK and northwest TX and a modest contraction over portions of southeast CO, southwest KS, and northwest OK. By afternoon, sustained wind speeds of 20-30 mph (with higher gusts) are expected to coincide with marginally reduced RH values near 25% and dry/dormant fuels to support Elevated fire weather conditions. See previous discussion below for more information. ..Elliott.. 02/19/2018 .PREV DISCUSSION... /ISSUED 0104 AM CST Mon Feb 19 2018/ ...Synopsis... An upper-level trough over the West will shift eastward today as a midlevel speed max moves through the base of the trough. This pattern will continue to support strong southwesterly flow aloft over the southern High Plains. In response at the surface, a strengthening low pressure system will develop over Colorado during the afternoon hours. ...Portions of the Southern High Plains... An increasing surface pressure gradient coupled with downward vertical mixing of high momentum air from aloft will contribute to windy conditions today across much of the Southwest and southern High Plains. While sustained afternoon wind speeds will exceed critical thresholds across the region (30 mph across southeastern Colorado/northeastern New Mexico decreasing to 20 mph farther east into western Oklahoma), RH values are expected to remain above critical thresholds (generally at or above 25%). Nevertheless, fire weather conditions will be elevated given the ongoing drought, dry/dormant fuels, and strong winds across the region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 10:35
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1034 AM CST Mon Feb 19 2018 Valid 191700Z - 201200Z Relatively minor modifications were made to the Elevated fire weather area over the Southern High plains to account for the latest high-resolution guidance from the HRRR/HREF/RAP and observational data. Primary adjustments include a slight extension farther into western OK and northwest TX and a modest contraction over portions of southeast CO, southwest KS, and northwest OK. By afternoon, sustained wind speeds of 20-30 mph (with higher gusts) are expected to coincide with marginally reduced RH values near 25% and dry/dormant fuels to support Elevated fire weather conditions. See previous discussion below for more information. ..Elliott.. 02/19/2018 .PREV DISCUSSION... /ISSUED 0104 AM CST Mon Feb 19 2018/ ...Synopsis... An upper-level trough over the West will shift eastward today as a midlevel speed max moves through the base of the trough. This pattern will continue to support strong southwesterly flow aloft over the southern High Plains. In response at the surface, a strengthening low pressure system will develop over Colorado during the afternoon hours. ...Portions of the Southern High Plains... An increasing surface pressure gradient coupled with downward vertical mixing of high momentum air from aloft will contribute to windy conditions today across much of the Southwest and southern High Plains. While sustained afternoon wind speeds will exceed critical thresholds across the region (30 mph across southeastern Colorado/northeastern New Mexico decreasing to 20 mph farther east into western Oklahoma), RH values are expected to remain above critical thresholds (generally at or above 25%). Nevertheless, fire weather conditions will be elevated given the ongoing drought, dry/dormant fuels, and strong winds across the region. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/19/2018 - 05:46

000
AXNT20 KNHC 191146
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
646 AM EST Mon Feb 19 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 high pressure in the western Atlantic and
lower pressures in northern sections of S America. This pattern
supports winds pulsing to minimal gale-force near the coast of
Colombia every night/early morning hours through the week. Wave
heights within the area of 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 coast of Africa near
07N12W southwestward to 03N15W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W. The ITCZ continues from that point to
03N39W. Scattered moderate isolated strong convection is within
120 nm S of the axis between 25W-29W, and within 60 nm N of the
axis between 18W-20W. Scattered moderate convection is within
30 nm of the axis between 12W-14W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward from a 1027 mb high centered
over the Atlantic near 28N64W to a 1023 mb high centered just
west of the coast of Florida at 29N83W, and weakens as it
continues to NW Gulf. The NW part of a surface trough extends off
the NW coast of Cuba to near 23N85W. A surface trough is along the
west coast of the Yucatan Peninsula. The earlier scattered
moderate convection noted near this trough has dissipated.
Isolated showers are S of 21N and E of 94W. Isolated showers
are S of 22N between 91W-95W. Patches of fog lifting northward
are seen over the NW Gulf early this morning. Expect these patches
of fog to linger through the morning, with other patches of fog
possible to form along and near the coastal sections of the N
central and NE portions of the gulf. Both buoy observations and
scatterometer data from last night indicate generally light to
gentle east to southeast flow N of of 26N, and gentle to moderate
east to southeast winds S of 26N, except for higher winds in the
moderate to fresh range E of 88W and W of 94W. Expect increasing
winds and building seas beginning today as high pressure
strengthens in the western Atlantic Ocean. The thermal trough
will develop over the western Yucatan Peninsula through Wed
afternoon, drift westward across the eastern Bay of Campeche
during the overnight hours, and then dissipate in the SW Gulf
waters by the late morning hours.

CARIBBEAN SEA...

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

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with passing isolated
showers, except over the far western Caribbean from 14N-18N W of
81W, including the Gulf of Honduras, where patches of overcast
to broken low clouds contain scattered showers. Overall shower
activity across the basin has decreased during the past 24 to 48
hours as abundant dry sinking air aloft maintains is influence on
the atmosphere. This same gradient 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 one today. The pressure
gradient associated with the stronger high system will bring
increasing winds and building seas across the eastern and
central Caribbean, and the Tropical N Atlantic waters through
Wed.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1027 mb high center near 28N64W and a 1024 mb high center near
30N37W. A weakness in the ridge is noted as a surface trough that
extends from 28N44W to 19N45W. A backdoor type cold front has
nudged southward to roughly along 31N between 72W-80W, becoming
a stationary front northwestward to inland Georgia at 32N81W. A
pre-frontal trough is just ahead of the front between 72W-76W.
Only scattered low clouds are seen along the trough, while very
minimal cloudiness is near the front. The cold front will become
stationary today and dissipate by early Tue. Current satellite
imagery is depicting low clouds (stratus) and fog over the
extreme far northwest waters along the NE Florida coast. These
clouds and fog are slowly moving inland that coast. The existing
area of high pressure is forecast to be fortified by stronger
high pressure system through Wed.

Currently 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 is observed streaming northeastward from
northeastern S America to within 360 nm either side of a line
from 02N50W to 13N34W to 18N25W to the coast of Africa at 21N17W,
where the moisture thins out. This area of moisture and clouds
are driven by a rather strong jet stream branch that is along the
southeastern sector of a broad and persistent central Atlantic
upper level trough. Scattered moderate convection is within 60 nm
of a line from 01N37W to the Equator at 43W. Isolated showers
are possible elsewhere from the Equator to 11N to the west of
35W, and also from 14N-21N between 17W-30W.

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

$$

ERA/JA

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 01:09
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0105 AM CST Mon Feb 19 2018 Valid 201200Z - 211200Z ...Synopsis... An upper-level trough over the West will weaken on Tuesday as a midlevel speed max ejects downstream across the Upper Mississippi Valley. At the surface, a low pressure system will lift northeast toward the Great Lakes with an associated cold front slowly advancing southeastward over the plains. ...Portions of Southern High Plains... Although the wind speeds aloft will be weakening compared to previous days, sufficient flow will likely yield sustained afternoon surface wind speeds approaching 20 mph through boundary layer mixing processes. Downslope westerly flow will also support warming/drying at the surface, resulting in afternoon RH values below 20% despite relatively cool temperatures across the region (generally at or below 60F). Overall, these meteorological conditions support elevated fire weather conditions given the dry fuels across the region. ..Jirak.. 02/19/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Mon, 02/19/2018 - 01:08
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0104 AM CST Mon Feb 19 2018 Valid 191200Z - 201200Z ...Synopsis... An upper-level trough over the West will shift eastward today as a midlevel speed max moves through the base of the trough. This pattern will continue to support strong southwesterly flow aloft over the southern High Plains. In response at the surface, a strengthening low pressure system will develop over Colorado during the afternoon hours. ...Portions of the Southern High Plains... An increasing surface pressure gradient coupled with downward vertical mixing of high momentum air from aloft will contribute to windy conditions today across much of the Southwest and southern High Plains. While sustained afternoon wind speeds will exceed critical thresholds across the region (30 mph across southeastern Colorado/northeastern New Mexico decreasing to 20 mph farther east into western Oklahoma), RH values are expected to remain above critical thresholds (generally at or above 25%). Nevertheless, fire weather conditions will be elevated given the ongoing drought, dry/dormant fuels, and strong winds across the region. ..Jirak.. 02/19/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/19/2018 - 00:39

000
AXNT20 KNHC 190639 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
105 AM EST Mon Feb 19 2018

Corrected Gulf of Mexico 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
0545 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 pressures in northern sections of S America.
This pattern supports winds pulsing to minimal gale force near the
coast of Colombia through early next week. Wave heights within
the area of gale force winds will range between 12-17 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 coast of Africa near
07N12W southwestward to 03N15W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W. The ITCZ continues from that point to
03N39W. Scattered moderate isolated strong convection is within
120 nm S of the axis between 25W-29W, and within 60 nm N of the
axis between 18W-20W. Scattered moderate convection is within
30 nm of the axis between 12W-14W.

...DISCUSSION...

GULF OF MEXICO...Corrected

A surface ridge extends westward from a 1027 mb high centered
over the Atlantic near 28N64W to a 1023 mb high centered just
west of the coast of Florida at 29N83W, and weakens as it
continues to NW Gulf. The NW part of a surface trough extends off
the NW coast of Cuba to near 23N85W. A surface trough is along the
west coast of the Yucatan Peninsula. The earlier scattered
moderate convection noted near this trough has dissipated.
Isolated showers are S of 21N and E of 94W. Isolated showers
are S of 22N between 91W-95W. Patches of fog lifting northward
are seen over the NW Gulf early this morning. Expect these patches
of fog to linger through the morning, with other patches of fog
possible to form along and near the coastal sections of the N
central and NE portions of the gulf. Both buoy observations and
scatterometer data from last night indicate generally light to
gentle east to southeast flow N of of 26N, and gentle to moderate
east to southeast winds S of 26N, except for higher winds in the
moderate to fresh range E of 88W and W of 94W. Expect increasing
winds and building seas beginning today as high pressure
strengthens in the western Atlantic Ocean. The thermal trough
will develop over the western Yucatan Peninsula through Wed
afternoon, drift westward across the eastern Bay of Campeche
during the overnight hours, and then dissipate in the SW Gulf
waters by the late morning hours.

CARIBBEAN SEA...

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

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with passing isolated
showers, except over the far western Caribbean from 14N-18N W of
81W, including the Gulf of Honduras, where patches of overcast
to broken low clouds contain scattered showers. Overall shower
activity across the basin has decreased during the past 24 to 48
hours as abundant dry sinking air aloft maintains is influence on
the atmosphere. This same gradient 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 one today. The pressure
gradient associated with the stronger high system will bring
increasing winds and building seas across the eastern and
central Caribbean, and the Tropical N Atlantic waters through
Wed.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1027 mb high center near 28N64W and a 1024 mb high center near
30N37W. A weakness in the ridge is noted as a surface trough that
extends from 28N44W to 19N45W. A backdoor type cold front has
nudged southward to roughly along 31N between 72W-80W, becoming
a stationary front northwestward to inland Georgia at 32N81W. A
pre-frontal trough is just ahead of the front between 72W-76W.
Only scattered low clouds are seen along the trough, while very
minimal cloudiness is near the front. The cold front will become
stationary today and dissipate by early Tue. Current satellite
imagery is depicting low clouds (stratus) and fog over the
extreme far northwest waters along the NE Florida coast. These
clouds and fog are slowly moving inland that coast. The existing
area of high pressure is forecast to be fortified by stronger
high pressure system through Wed.

Currently 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 is observed streaming northeastward from
northeastern S America to within 360 nm either side of a line
from 02N50W to 13N34W to 18N25W to the coast of Africa at 21N17W,
where the moisture thins out. This area of moisture and clouds
are driven by a rather strong jet stream branch that is along the
southeastern sector of a broad and persistent central Atlantic
upper level trough. Scattered moderate convection is within 60 nm
of a line from 01N37W to the Equator at 43W. Isolated showers
are possible elsewhere from the Equator to 11N to the west of
35W, and also from 14N-21N between 17W-30W.

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

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/19/2018 - 00:05

000
AXNT20 KNHC 190605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 AM EST Mon Feb 19 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
continues between a surface high pressure in the western Atlantic
and lower surface pressures in northern sections of S America.
This pattern supports winds pulsing to minimal gale force near the
coast of Colombia through early next week. Wave heights within
the area of gale force winds will range between 12-17 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 coast of Africa near
07N12W southwestward to 03N15W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W. The ITCZ continues from that point to
03N39W. Scattered moderate isolated strong convection is within
120 nm S of the axis between 25W-29W, and within 60 nm N of the
axis between 18W-20W. Scattered moderate convection is within
30 nm of the axis between 12W-14W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward from a 1027 mb high centered
over the Atlantic near 28N64W to a 1023 mb high centered just
west of the coast of Florida at 29N83W, and weakens as it
continues to NW Gulf. The NW part of a surface trough extends off
the NW coast of Cuba to near 23N85W. A surface trough is along the
west coast of the Yucatan Peninsula. The earlier scattered
moderate convection noted near this trough has dissipated.
Isolated showers are S of 21N and E of 94W. Isolated showers
are S of 22N between 91W-95W. Patches of fog lifting northward
are seen over the NW Gulf early this morning. Expect these patches
of fog to linger through the morning, with other patches of fog
possible to form along and near the coastal sections of the N
central and NE portions of the gulf. Both buoy observations and
scatterometer data from last night indicate generally light to
gentle east to southeast flow N of of 26N, and gentle to moderate
east to southeast winds S of 26N, except for higher winds in the
moderate to fresh range E of 88W and W of 94W. Expect increasing
winds and building seas beginning on Mon as high pressure
strengthens in the western Atlantic Ocean. The thermal trough will
develop over the western Yucatan Peninsula Mon and Tue afternoon,
drift westward across the eastern Bay of Campeche during the
overnight hours, and then dissipate in the SW Gulf waters by the
late morning hours.

CARIBBEAN SEA...

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

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with passing isolated
showers, except over the far western Caribbean from 14N-18N W of
81W, including the Gulf of Honduras, where patches of overcast
to broken low clouds contain scattered showers. Overall shower
activity across the basin has decreased during the past 24 to 48
hours as abundant dry sinking air aloft maintains is influence on
the atmosphere. This same gradient 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 one system on Mon. This stronger
system will bring increasing winds and building seas across the
eastern and central Caribbean, and the Tropical N Atlantic waters
possibly into the middle of next week.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1027 mb high center near 28N64W and a 1024 mb high center near
30N37W. A weakness in the ridge is noted as a surface trough that
extends from 28N44W to 19N45W. A backdoor type cold front has
nudged southward to roughly along 31N between 72W-80W, becoming
a stationary front northwestward to inland Georgia at 32N81W. A
pre-frontal trough is just ahead of the front between 72W-76W.
Only scattered low clouds are seen along the trough, while very
minimal cloudiness is near the front. The cold front will become
stationary today and dissipate by early Tue. Satellite imagery is
depicting low clouds and fog over the extreme far northwest
waters along the NE Florida coast. These clouds and fog are slowly
moving inland that coast. The existing area of high pressure is
forecast to be fortified by stronger high pressure system through
Wed.

Currently 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 is observed streaming northeastward from
northeastern S America to within 360 nm either side of a line
from 02N50W to 13N34W to 18N25W to the coast of Africa at 21N17W,
where the moisture thins out. This area of moisture and clouds
are driven by a rather strong jet stream branch that is along the
southeastern sector of a broad and persistent central Atlantic
upper level trough. Scattered moderate convection is within 60 nm
of a line from 01N37W to the Equator at 43W. Isolated showers are
possible elsewhere from the Equator to 11N west of 35W, and from
14N-21N between 17W-30W.

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

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sun, 02/18/2018 - 23:19

000
AXNT20 KNHC 190519 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
705 PM EST Sun Feb 18 2018

Corrected 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 1800 UTC surface analysis and satellite imagery through
2345 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 pressures in northern sections of South
America. This pattern supports winds pulsing to minimal gale force
near the coast of Colombia through early next week. Wave heights
within the area of gale force winds will range between 12-17 ft.
Please read the latest NHC High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...Corrected

The monsoon trough axis extends from the coast of Africa near
06N10W southwestward to 03N14W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W. The ITCZ continues from that point to
03N39W. Scattered moderate convection is within 30 nm N of the
axis between 18W-19W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward from a 1026 mb high centered
over the Atlantic near 28N64W to 1023 mb high centered over
central Florida, and continues westward to the NW Gulf. The
earlier frontal boundary that was along the coastal plains has N
of the as a warm front, and is over eastern Texas and the southern
portions of Louisiana, Mississippi and Alabama. A rather weak
surface trough is over the NE Gulf from 30N86W to 27N88W. Earlier
related shower activity has dissipated. Another surface trough
has recently emerged off the west coast of the Yucatan Peninsula
to over the far eastern Bay of Campeche. Isolated showers are S
of 21N and E of 94W. Areas of fog are expected over portions of
the northern and central gulf during the overnight hours and
into Mon morning. Both buoy observations and latest
scatterometer data reveal generally light to gentle east to
southeast flow N of of 26N, and gentle to moderate east to
southeast winds S of 26N, except for higher winds in the
moderate to fresh range E of 88W and W of 94W. Expect increasing
winds and building seas by early next week as high pressure
strengthens in the western Atlantic Ocean. The thermal trough
will develop again over the western Yucatan Peninsula each
afternoon, drift westward across the eastern Bay of Campeche
during the overnight hours, and then dissipate in the SW Gulf
waters by the late morning hours.

CARIBBEAN SEA...

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

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with quick passing
isolated showers, except over the far western Caribbean from
14N-18N W of 83W, including the Gulf of Honduras, where patches
of overcast low clouds contain scattered showers. This same
gradient 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
one system on Mon. This stronger system will bring increasing
winds and building seas across the eastern and central Caribbean,
and the Tropical N Atlantic waters possibly into the middle of
next week.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1026 mb high center near 28N64W and a 1024 mb high center near
31N34W. A weakness in the ridge was analyzed as a surface trough,
extending from 28N44W to 19N45W. The tail end of a stationary
front is along 32N from 44W-51W, while a cold front is just along
32N W of 72W. The cold front will drop southward over the NW
waters tonight and dissipate on Mon. The ridge will be reinforced
by a stronger high pressure system through Tuesday.

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

$$
Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

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

000
AXNT20 KNHC 190005
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 PM 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 1800 UTC surface analysis and satellite imagery through
2345 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 pressures in northern sections of South
America. This pattern supports winds pulsing to minimal gale force
near the coast of Colombia through early next week. Wave heights
within the area of gale force winds will range between 12-17 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 coast of Africa near
06N10W southwestward to 03N14W and dips below the Equator at 19W
where it transitions to the ITCZ axis to 02S29W and to the coast
of S America at 03S39W. 07N12W to 00N22W. The ITCZ continues from
that point to 03N39W. Scattered moderate convection is within 30
nm N of the axis between 18W-19W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends westward from a 1026 mb high centered
over the Atlantic near 28N64W to 1023 mb high centered over
central Florida, and continues westward to the NW Gulf. The
earlier frontal boundary that was along the coastal plains has N
of the as a warm front, and is over eastern Texas and the southern
portions of Louisiana, Mississippi and Alabama. A rather weak
surface trough is over the NE Gulf from 30N86W to 27N88W. Earlier
related shower activity has dissipated. Another surface trough
has recently emerged off the west coast of the Yucatan Peninsula
to over the far eastern Bay of Campeche. Latest satellite imagery
shows a recently formed cluster of scattered moderate convection
moving northwestward within 30 nm of 92W. Isolated showers are S
of 21N and E of 94W. Areas of fog are expected over portions of
the northern and central gulf during the overnight hours and into
Mon morning. Both buoy observations and latest scatterometer data
reveal generally light to gentle east to southeast flow N of of
26N, and gentle to moderate east to southeast winds S of 26N,
except for higher winds in the moderate to fresh range E of 88W
and W of 94W. Expect increasing winds and building seas by early
next week as high pressure strengthens in the western Atlantic
Ocean. The thermal trough will develop again over the western
Yucatan Peninsula each afternoon, drift westward across the
eastern Bay of Campeche during the overnight hours, and then
dissipate in the SW Gulf waters by the late morning hours.

CARIBBEAN SEA...

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

A tight pressure gradient across the basin created by the
combination of high pressure over the central Atlantic and lower
pressure over NW Colombia is producing strong east winds
throughout. These winds continue to quickly advect patches of
mainly broken low clouds westward along with quick passing
isolated showers, except over the far western Caribbean from
14N-18N W of 83W, including the Gulf of Honduras, where patches
of overcast low clouds contain scattered showers. This same
gradient 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
one system on Mon. This stronger system will bring increasing
winds and building seas across the eastern and central Caribbean,
and the Tropical N Atlantic waters possibly into the middle of
next week.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1026 mb high center near 28N64W and a 1024 mb high center near
31N34W. A weakness in the ridge was analyzed as a surface trough,
extending from 28N44W to 19N45W. The tail end of a stationary
front is along 32N from 44W-51W, while a cold front is just along
32N W of 72W. The cold front will drop southward over the NW
waters tonight and dissipate on Mon. The ridge will be reinforced
by a stronger high pressure system through Tuesday.

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 - 13:14
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 PM CST Sun Feb 18 2018 Valid 191200Z - 201200Z The elevated area has been expanded southeastward to include more of the Texas Panhandle, portions of western North Texas, and western Oklahoma. Models persist in keeping relatively high RH values west of the surface trough/dryline, with only a limited area of mixing sufficient for sub-25% RH values (confined mostly to the elevated delineation). Surface winds will exceed critical thresholds (perhaps 30-35 mph sustained across northeastern NM and vicinity), and observations/model trends will be monitored in that area for lower-than-depicted RH values, which may necessitate a critical upgrade (most likely in portions of southeastern Colorado and the Oklahoma Panhandle). See the previous discussion below for more information. ..Cook.. 02/18/2018 .PREV DISCUSSION... /ISSUED 0207 AM CST Sun Feb 18 2018/ ...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. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sun, 02/18/2018 - 13:14
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0112 PM CST Sun Feb 18 2018 Valid 191200Z - 201200Z The elevated area has been expanded southeastward to include more of the Texas Panhandle, portions of western North Texas, and western Oklahoma. Models persist in keeping relatively high RH values west of the surface trough/dryline, with only a limited area of mixing sufficient for sub-25% RH values (confined mostly to the elevated delineation). Surface winds will exceed critical thresholds (perhaps 30-35 mph sustained across northeastern NM and vicinity), and observations/model trends will be monitored in that area for lower-than-depicted RH values, which may necessitate a critical upgrade (most likely in portions of southeastern Colorado and the Oklahoma Panhandle). See the previous discussion below for more information. ..Cook.. 02/18/2018 .PREV DISCUSSION... /ISSUED 0207 AM CST Sun Feb 18 2018/ ...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. ...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 - 11:37

000
AXNT20 KNHC 181737
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1237 PM 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 1200 UTC surface analysis and satellite imagery through
1715 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 pressures in northern sections of South
America. This pattern supports winds pulsing to minimal gale force
near the coast of Colombia through early next week. Wave heights
within the area of 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 enters the eastern Atlantic near 07N12W
to 00N22W. The ITCZ continues from that point to 03N39W.
Scattered moderate convection is within 60 nm on either side of
the ITCZ between 23W and 40W.

...DISCUSSION...

GULF OF MEXICO...

A surface ridge extends across the basin anchored by a 1023 mb
high centered over central Florida. A frontal boundary extends
across the coastal Gulf states with little to no convection at
this time. A subtle pre-frontal trough is over the northeast
waters from 30N86W to 28N88W. Scattered showers are noted with
this trough. To the southwest, a surface trough continues moving
westward across the Bay of Campeche with no convection.
Scatterometer data depicts light to gentle southeasterly winds
over the northern half of the basin while gentle to moderate
southeast winds prevail south of 25N. Expect increasing winds
and building seas by early next week as high pressure strengthens
in the western Atlantic Ocean. The thermal trough will develop
again over the western Yucatan Peninsula each afternoon, drifting
westward across the eastern Bay of Campeche during the overnight
hours, and then dissipate in the SW Gulf waters by the late
morning hours.

CARIBBEAN SEA...

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

Scattered low-topped showers will continue moving across the
basin transported by moderate to fresh trades. The 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
one system on Monday. This stronger system will bring increasing
winds and building seas across the eastern and central Caribbean,
and the Tropical N Atlantic waters possibly into the middle of
next week.

ATLANTIC OCEAN...

Broad area of high pressure prevails across the basin, centered by
a 1026 mb high near 28N67W and a 1025 mb high near 29N39W. A
weakness in the ridge was analyzed as a surface trough, extending
from 28N43W to 20N44W. A frontal system extends north of the area
across the central Atlantic between 40W-60W. The eastmost portion
of the front will approach 30N during the next 24 hours with some
convection. Another weak frontal boundary will approach the west
Atlantic from the north by the same time with showers. The ridge
will be reinforced by a stronger high pressure system through
Tuesday.

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

$$

ERA

Categories: Weather

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