Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 02/14/2018 - 17:58

000
AXNT20 KNHC 142358
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
658 PM EST Wed Feb 14 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 strong surface ridge in the north Atlantic
and lower surface pressures in northern South America. This
scenario is supporting gale-force winds near the coast of
Colombia through the week. The sea heights associated with these
wind conditions are forecast to range from 12 feet to 16 feet,
subsiding some later in the week. 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 sections of Sierra Leone
near 08N13W to 08N15W, 05N20W, and 02N24W. The ITCZ continues
from 02N24W, crossing the Equator along 26W, to 05S34W.
Precipitation: isolated moderate to locally strong rainshowers
from 10N southward from 60W eastward. Upper level SW wind flow is
to the SE of the line that passes through 28N13W 22N30W 16N50W
12N63W.

...DISCUSSION...

GULF OF MEXICO...

The western part of the stationary front, from the MIATWDAT
bulletin of 14/1205 UTC, has moved northward into parts of
Louisiana and eastern Texas as a warm front. The front is
stationary from Florida near 28N81W, to SE coastal Louisiana.
The front is warm for the western of the Louisiana coastal plains,
into the upper Texas Gulf coast, to 27N96W in the Texas coastal
waters. A surface trough continues from 27N96W, into the SW corner
of the Gulf of Mexico near 19N95W. Overcast low level clouds and
areas of fog/haze and possible precipitation are near and to the
north of the frontal boundary, in the waters and in the coastal
plains. rainshowers are possible, also, from 23N southward from
93W westward.

The current frontal boundary will weaken into a trough today. E
to SE winds generated by a ridge, extending from the Atlantic
Ocean into the central Gulf of Mexico, will prevail across the
basin through Saturday. A weak cold front will stall in the
northern Gulf of Mexico on Sunday.

CARIBBEAN SEA...

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

Scattered showers are possible in areas of broken-to-overcast low
level clouds across the entire area. Strong trade winds will
continue to the east of 80W, including in the Atlantic Ocean
passages, through Thursday morning. Winds to minimal gale-force
will persist near the coast of Colombia through Sunday night.
Winds and seas outside the central Caribbean Sea will subside
gradually from Thursday through Saturday.

ATLANTIC OCEAN...

A frontal boundary is along 31N/32N from 60W westward, to
a 1028 mb low pressure center that is near 31N78W. A stationary
front continues from the 1028 mb low center, to Florida near
28N81W, and then westward into the northern sections of the Gulf
of Mexico. Broken overcast low level clouds and possible
rainshowers are to the NW of the line that passes through 32N43W
to 30N60W, to 28N70W, and to 25N80W.

An upper level trough extends from a 22N32W cyclonic circulation
center, to 14N56W, to 16N71W in the Caribbean Sea, and weaker from
16N71W to the coast of Nicaragua. rainshowers are possible from
20N to 24N between 28W and 34W.

An east-to-west oriented ridge that is along 29N will remain in
place through Sunday night. A stationary front in the far NW
waters will dissipate tonight. Light to gentle winds will prevail
north of 25N, with moderate to fresh winds expected south of 25N
through Sunday. A weak cold front will move off the SE U.S. coast
on Sunday.

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

$$

MT/ERA

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 13:01
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1259 PM CST Wed Feb 14 2018 Valid 151200Z - 161200Z The previous forecast is on track and no updates are needed. See discussion below for more details. ..Leitman.. 02/14/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Wed Feb 14 2018/ ...Synopsis... Positively tilted upper troughing over the western CONUS is forecast to develop eastward across the Plains on Day 2/Thursday. A broad belt of enhanced mid-level winds will persist across roughly the eastern two-thirds of the country as an upper ridge becomes suppressed over the Gulf of Mexico. At the surface, an area of low pressure will likely be centered over western KS at the start of the period, with a lee trough extending southward from this low across the southern High Plains. This surface low should develop southeastward in tandem with a cold front, reaching the vicinity of the eastern TX/OK Panhandles by Thursday evening. An area of high pressure should develop over the northern Great Basin with large-scale subsidence occurring behind the upper trough. ...Portions of the Southern/Central High Plains... Elevated conditions may occur across parts of the central/southern High Plains in advance of the cold front and surface low mentioned above. Sustained westerly winds of 15-25 appear likely, although RH values may struggle to fall much below 20% due to widespread mid/upper-level cloudiness limiting surface heating. Still, favorable low-level trajectories suggest at least some downslope warming/drying will occur Thursday afternoon, and the potential for RH values falling as low as 18-20% is enough for an elevated delineation extending from parts of northeastern NM and far southeastern CO into the TX/OK Panhandles, far southwestern KS, and northwestern OK. The lack of an even warmer/drier low-level airmass precludes a critical area. ...Portions of Southern CA... The surface pressure gradient is forecast to modestly strengthen across portions of southern CA beginning Thursday evening and continuing through early Friday morning. This should promote an increase in northeasterly offshore winds for parts of the coastal ranges and adjacent foothills. Sustained winds of 15-20 mph appear likely, with some higher gusts up to 40 mph possible. Downslope warming/drying processes should act to lower RH values into the 10-20% range overnight. There is some potential for light precipitation across portions of southern CA on Day 1/Wednesday as an upper low moves northeastward and becomes absorbed into large-scale upper troughing over the western CONUS. Regardless, precipitation amounts are forecast to be light, and these meteorological conditions support the introduction of a small elevated area since fuels are expected to remain receptive to large fire starts/spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 13:01
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1259 PM CST Wed Feb 14 2018 Valid 151200Z - 161200Z The previous forecast is on track and no updates are needed. See discussion below for more details. ..Leitman.. 02/14/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Wed Feb 14 2018/ ...Synopsis... Positively tilted upper troughing over the western CONUS is forecast to develop eastward across the Plains on Day 2/Thursday. A broad belt of enhanced mid-level winds will persist across roughly the eastern two-thirds of the country as an upper ridge becomes suppressed over the Gulf of Mexico. At the surface, an area of low pressure will likely be centered over western KS at the start of the period, with a lee trough extending southward from this low across the southern High Plains. This surface low should develop southeastward in tandem with a cold front, reaching the vicinity of the eastern TX/OK Panhandles by Thursday evening. An area of high pressure should develop over the northern Great Basin with large-scale subsidence occurring behind the upper trough. ...Portions of the Southern/Central High Plains... Elevated conditions may occur across parts of the central/southern High Plains in advance of the cold front and surface low mentioned above. Sustained westerly winds of 15-25 appear likely, although RH values may struggle to fall much below 20% due to widespread mid/upper-level cloudiness limiting surface heating. Still, favorable low-level trajectories suggest at least some downslope warming/drying will occur Thursday afternoon, and the potential for RH values falling as low as 18-20% is enough for an elevated delineation extending from parts of northeastern NM and far southeastern CO into the TX/OK Panhandles, far southwestern KS, and northwestern OK. The lack of an even warmer/drier low-level airmass precludes a critical area. ...Portions of Southern CA... The surface pressure gradient is forecast to modestly strengthen across portions of southern CA beginning Thursday evening and continuing through early Friday morning. This should promote an increase in northeasterly offshore winds for parts of the coastal ranges and adjacent foothills. Sustained winds of 15-20 mph appear likely, with some higher gusts up to 40 mph possible. Downslope warming/drying processes should act to lower RH values into the 10-20% range overnight. There is some potential for light precipitation across portions of southern CA on Day 1/Wednesday as an upper low moves northeastward and becomes absorbed into large-scale upper troughing over the western CONUS. Regardless, precipitation amounts are forecast to be light, and these meteorological conditions support the introduction of a small elevated area since fuels are expected to remain receptive to large fire starts/spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 02/14/2018 - 11:41

000
AXNT20 KNHC 141741
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1241 PM EST Wed Feb 14 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
that exists between a strong surface ridge in the north Atlantic
Ocean, and lower surface pressures in northern South America,
will continue to support gale-force winds near the coast of
Colombia through the week. The sea heights associated with these
gale-force wind conditions are forecast to range from 12 feet to
17 feet, subsiding some later in the week. 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 sections of Sierra Leone
near 08N13W to 08N15W, 05N20W, and 02N24W. The ITCZ continues
from 02N24W, crossing the Equator along 26W, to 05S34W.
Precipitation: isolated moderate to locally strong rainshowers
from 10N southward from 60W eastward. Upper level SW wind flow is
to the SE of the line that passes through 28N13W 22N30W 16N50W
12N63W.

...DISCUSSION...

GULF OF MEXICO...

The western part of the stationary front, from the MIATWDAT
bulletin of 14/1205 UTC, has moved northward into parts of
Louisiana and eastern Texas as a warm front. The front is
stationary from Florida near 28N81W, to SE coastal Louisiana.
The front is warm for the western of the Louisiana coastal plains,
into the upper Texas Gulf coast, to 27N96W in the Texas coastal
waters. A surface trough continues from 27N96W, into the SW corner
of the Gulf of Mexico near 19N95W. Overcast low level clouds and
areas of fog/haze and possible precipitation are near and to the
north of the frontal boundary, in the waters and in the coastal
plains. rainshowers are possible, also, from 23N southward from
93W westward.

The current frontal boundary will weaken into a trough today. E
to SE winds generated by a ridge, extending from the Atlantic
Ocean into the central Gulf of Mexico, will prevail across the
basin through Saturday. A weak cold front will stall in the
northern Gulf of Mexico on Sunday.

CARIBBEAN SEA...

Please read the SPECIAL FEATURES section, for details about 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 14/1200 UTC...according
to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...
MIATPTPAN/SXCA01 KNHC...are: 0.62 in Montego Bay in Jamaica, 0.23
in Guadeloupe, 0.13 in Curacao, 0.07 in San Juan in Puerto Rico,
0.01 in Freeport in the Bahamas.

Strong trade winds will continue to the east of 80W, including in
the Atlantic Ocean passages, through Thursday morning. Winds to
minimal gale-force will persist near the coast of Colombia through
Sunday night. Winds and seas outside the central Caribbean Sea
will subside gradually from Thursday through Saturday.

ATLANTIC OCEAN...

A frontal boundary is along 31N/32N from 60W westward, to
a 1028 mb low pressure center that is near 31N78W. A stationary
front continues from the 1028 mb low center, to Florida near
28N81W, and then westward into the northern sections of the Gulf
of Mexico. Broken overcast low level clouds and possible
rainshowers are to the NW of the line that passes through 32N43W
to 30N60W, to 28N70W, and to 25N80W.

An upper level trough extends from a 22N32W cyclonic circulation
center, to 14N56W, to 16N71W in the Caribbean Sea, and weaker from
16N71W to the coast of Nicaragua. rainshowers are possible from
20N to 24N between 28W and 34W.

An east-to-west oriented ridge that is along 29N will remain in
place through Sunday night. A stationary front in the far NW
waters will dissipate tonight. Light to gentle winds will prevail
north of 25N, with moderate to fresh winds expected south of 25N
through Sunday. A weak cold front will move off the SE U.S. coast
on Sunday.

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

$$
MT
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 09:39
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0936 AM CST Wed Feb 14 2018 Valid 141700Z - 151200Z The ongoing forecast is on track and no changes are needed. See discussion below for details. ..Leitman.. 02/14/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Wed Feb 14 2018/ ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS today as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin. Enhanced mid-level west-southwesterly winds of 50-70 kt will overspread the southern/central High Plains by this afternoon. At the surface, a low is forecast to deepen across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will increase into generally the 15-25 mph range by early this afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours, supporting widespread elevated conditions across this region where fuels are dry/dormant. There should be some locally critical fire weather conditions where RH values can fall below 15%. But, this should occur on just a brief/isolated basis from northeastern NM into parts of the TX/OK Panhandles and perhaps northwestern OK, with mid/high-level cloudiness streaming eastward from the upper low limiting surface heating slightly. Have not included a critical delineation at this time mainly due to the limited forecast duration of such conditions this afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 09:39
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0936 AM CST Wed Feb 14 2018 Valid 141700Z - 151200Z The ongoing forecast is on track and no changes are needed. See discussion below for details. ..Leitman.. 02/14/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Wed Feb 14 2018/ ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS today as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin. Enhanced mid-level west-southwesterly winds of 50-70 kt will overspread the southern/central High Plains by this afternoon. At the surface, a low is forecast to deepen across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will increase into generally the 15-25 mph range by early this afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours, supporting widespread elevated conditions across this region where fuels are dry/dormant. There should be some locally critical fire weather conditions where RH values can fall below 15%. But, this should occur on just a brief/isolated basis from northeastern NM into parts of the TX/OK Panhandles and perhaps northwestern OK, with mid/high-level cloudiness streaming eastward from the upper low limiting surface heating slightly. Have not included a critical delineation at this time mainly due to the limited forecast duration of such conditions this afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Wed, 02/14/2018 - 06:05

000
AXNT20 KNHC 141205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 AM EST Wed Feb 14 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 a strong surface ridge in the north Atlantic
Ocean, and lower surface pressures in northern South America,
will continue to support gale-force winds near the coast of
Colombia through the week. The sea heights associated with these
gale-force wind conditions are forecast to range from 12 feet to
15 feet, subsiding some later in the week. 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 sections of Sierra Leone
near 09N13W to 06N19W, 05N22W, and 02N25W. The ITCZ continues from
02N25W, crossing the Equator along 27W, to 02S33W, and 04S38W.
Precipitation: widely scattered moderate to isolated strong from
03N southward from 06W eastward. isolated moderate to locally
strong from 05N southward between 09W and 22W, and from 10N
southward between 37W and 52W. Rainshowers are possible elsewhere
from 10N southward from 60W eastward. Upper level SW wind flow is
to the SE of the line that passes through 28N13W 25N24W 16N50W
12N63W.

...DISCUSSION...

GULF OF MEXICO...

A stationary front, that is across the northern and western
Gulf, will weaken into a trough this morning. E to SE winds from
a ridge extending from the Atlantic into the central Gulf will
prevail over the basin through Sat. A weak cold front will stall
over the northern Gulf on Sun.

CARIBBEAN SEA...

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

Strong trade winds will continue east of 80W,
including Atlc passages, through Thu morning. Winds to minimal
gale force will persist near the coast of Colombia through Sun
night. Winds and seas outside the central Caribbean will gradually
subside Thu through Sat.

ATLANTIC OCEAN...

A frontal boundary is along 31N/32N from 60W westward, to
a 1028 mb low pressure center that is near 32N78W. A stationary
front continues from the 1028 mb low center, to Florida near
28N81W, and then westward into the northern sections of the Gulf
of Mexico. A 1030 mb high pressure center is near 29N69W.

A ridge, that is along 29N, will remain in place through the
weekend. A cold front in the far NW waters will stall and
dissipate by tonight. Light to gentle winds will prevail north of
25N, with moderate to fresh winds expected south of 25N through
Sunday. A weak cold front will move off the SE U.S. coast on
Sunday.

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

$$
MT
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 01:33
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0130 AM CST Wed Feb 14 2018 Valid 151200Z - 161200Z ...Synopsis... Positively tilted upper troughing over the western CONUS is forecast to develop eastward across the Plains on Day 2/Thursday. A broad belt of enhanced mid-level winds will persist across roughly the eastern two-thirds of the country as an upper ridge becomes suppressed over the Gulf of Mexico. At the surface, an area of low pressure will likely be centered over western KS at the start of the period, with a lee trough extending southward from this low across the southern High Plains. This surface low should develop southeastward in tandem with a cold front, reaching the vicinity of the eastern TX/OK Panhandles by Thursday evening. An area of high pressure should develop over the northern Great Basin with large-scale subsidence occurring behind the upper trough. ...Portions of the Southern/Central High Plains... Elevated conditions may occur across parts of the central/southern High Plains in advance of the cold front and surface low mentioned above. Sustained westerly winds of 15-25 appear likely, although RH values may struggle to fall much below 20% due to widespread mid/upper-level cloudiness limiting surface heating. Still, favorable low-level trajectories suggest at least some downslope warming/drying will occur Thursday afternoon, and the potential for RH values falling as low as 18-20% is enough for an elevated delineation extending from parts of northeastern NM and far southeastern CO into the TX/OK Panhandles, far southwestern KS, and northwestern OK. The lack of an even warmer/drier low-level airmass precludes a critical area. ...Portions of Southern CA... The surface pressure gradient is forecast to modestly strengthen across portions of southern CA beginning Thursday evening and continuing through early Friday morning. This should promote an increase in northeasterly offshore winds for parts of the coastal ranges and adjacent foothills. Sustained winds of 15-20 mph appear likely, with some higher gusts up to 40 mph possible. Downslope warming/drying processes should act to lower RH values into the 10-20% range overnight. There is some potential for light precipitation across portions of southern CA on Day 1/Wednesday as an upper low moves northeastward and becomes absorbed into large-scale upper troughing over the western CONUS. Regardless, precipitation amounts are forecast to be light, and these meteorological conditions support the introduction of a small elevated area since fuels are expected to remain receptive to large fire starts/spread. ..Gleason.. 02/14/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Wed, 02/14/2018 - 01:32
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0130 AM CST Wed Feb 14 2018 Valid 141200Z - 151200Z ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS today as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin. Enhanced mid-level west-southwesterly winds of 50-70 kt will overspread the southern/central High Plains by this afternoon. At the surface, a low is forecast to deepen across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will increase into generally the 15-25 mph range by early this afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours, supporting widespread elevated conditions across this region where fuels are dry/dormant. There should be some locally critical fire weather conditions where RH values can fall below 15%. But, this should occur on just a brief/isolated basis from northeastern NM into parts of the TX/OK Panhandles and perhaps northwestern OK, with mid/high-level cloudiness streaming eastward from the upper low limiting surface heating slightly. Have not included a critical delineation at this time mainly due to the limited forecast duration of such conditions this afternoon. ..Gleason.. 02/14/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/13/2018 - 23:25

000
AXNT20 KNHC 140525
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1225 AM EST Wed Feb 14 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
0515 UTC.

...SPECIAL FEATURES...

Caribbean Gale Warning: A tight gradient between a strong surface
ridge over the north Atlantic and lower pressures in northern
South America will continue to support gale-force winds near the
coast of Colombia through the week. Seas associated with these
gale conditions are forecast to be 12 to 15 ft, subsiding some
later in the week. Please read the latest NHC High Seas Forecast
under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends southwestward from the coast of Africa
near 09N13W to 01N26W. The ITCZ extends from that point to 04S37W.
No significant convection is related to these boundaries at this
time.

...DISCUSSION...

GULF OF MEXICO...

A stationary front extends across the northern portion of the
basin from 29N83W to 28N95W to 22N95W. No significant convection
is related to the front at this time. A surface trough extends
across the Bay of Campeche from 22N92W to 19N92W. Scattered
showers prevail along the southern portion of the trough.
Scatterometer data depicts gentle to moderate easterly winds over
the northern Gulf north of 27N while moderate to fresh easterly
winds are noted south of 27N. Expect for the front to continue
weakening and dissipate during the next 24 hours.

CARIBBEAN SEA...

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

A surface ridge north of the area anchored by a 1031 mb high over
the west Atlantic near 30N70W reaches the northern half of the
basin, with the associated pressure gradient supporting fresh to
strong trade winds between 68W-77W. Sea heights of 12 to 15 ft are
expected near Colombia and 8 to 12 ft elsewhere. Strong winds are
also occurring through the Atlantic passages, and are expected to
continue through at least Wed. Satellite water vapor imagery
shows dry and stable atmospheric conditions across the basin. Fast
westward moving shallow trade wind showers with gusty winds are
observed over the basin.

ATLANTIC OCEAN...

A weak 1028 mb surface low is centered north of the area, and
extending its cold front across the west Atlantic from 31N77W to
29N81W. NO convection is observed with this front. To the east, a
broad surface high pressure over the area is associated with a
1031 mb centered over the west Atlantic near 30N70W. Scatterometer
data depicts moderate to fresh easterly winds south 25N and west
of 40W, while gentle to moderate easterlies prevail elsewhere.
Expect for the front to become stationary across the central
Atlantic through Thursday. The next cold front is forecast to
move over the northwest forecast waters early this weekend.

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

$$

ERA

Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/13/2018 - 17:50

000
AXNT20 KNHC 132350
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
649 PM EST Tue Feb 13 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 Gale Warning: A tight gradient between a strong surface
ridge over the N Atlantic Ocean and lower pressures in northern
South America will continue to support gale-force winds near the
coast of Colombia during the night time hours through the week.
Seas associated with these gale conditions are forecast to be 14
to 18 ft, subsiding some later in the week. 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 southwestward from the coast of
Africa near 05N10W and crosses the equator near 19W. The ITCZ is
located to the S of the equator. Scattered moderate isolated
strong convection is within 120 nm S and 30 nm N of the axis
between 10W-12W. Similar is well S of the axis within 30 nm
of a line from 01N02W to 01N05W to 01N10W.

...DISCUSSION...

GULF OF MEXICO...

A cold front extends from the western Atlantic to inland NE
Florida where it becomes stationary southwestward to 29N88W
and a warm front from there to 27N94W to 26N96W S to 23N96W. It
transitions back to a stationary front again to inland the coast
of Mexico near Coatzacoalcos. A trough is ahead of the frontal
boundary from 23N93W to inland Mexico just W of Nuevo Progreso,
while another trough extends from just W of the front near 25N95W
northwestward to just S of Corpus Christi, Texas. Isolated showers
and thunderstorms moving northward are NW of the warm front
between 90W-95W. Patches of rain and isolated thunderstorms are
W of the stationary portion in the SW and far W central portions
of the gulf. Isolated showers in very moist moderate to fresh E
flow are over portions of the eastern gulf and Straits of Florida.
High pressure W of the front is surging southward over the NW
Gulf and across eastern Mexico. Strong northerly winds are S of
21N near the coast of Mexico. Moist southerly flow moving over the
NE Gulf ahead of the front in response to a mid to upper level
trough sliding eastward across the NE Gulf is producing widespread
showers north of 25N east of the trough. The warm front will
weaken as it slowly lifts northward as a warm front through
early on Wed.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details
about the gale-force winds expected near the coast of Colombia.

Satellite water vapor imagery shows dry and stable atmospheric
conditions across the basin. Fast westward moving shallow trade
wind showers, with gusty winds, are observed over much of the
basin, except in the lee of Cuba and waters between Haiti and 76W
and to the S of 13N between Colombia and 77W. The shower activity
is more prevalent N of 12N and E of 71W to across the Lesser
Antilles. Surface observations during the morning and early
afternoon hours indicated strong wind gusts with these showers as
they passed across the Leeward Islands and northern portion of
the Windward Islands. The island of Dominica reported a wind gust
to 34 kt at 16Z as a light shower went by. A strong ridge N of the
area anchored by a 1033 mb high over the central Atlc near 32N53W
extends across the northern half of the Caribbean, with the
associated pressure gradient supporting fresh to strong trade
winds east of 80W. Seas are 14 to 18 ft near Colombia and 8 to 12
ft elsewhere. Strong winds are also occurring through the Atlc
passages, and are expected to continue through at least Wed.

ATLANTIC OCEAN...

Broad surface high pressure over the area is associated with a
1033 mb centered over the N central Atlantic near 32N53W and
moving southwestward is supporting fresh to strong E-NE winds
over most of the region, except close to the ridge axis N of 25N.
Isolated showers, moving quickly westward, are noted from 13N to
18N and to the W of 52W, including over much of the Leeward
Islands. This shower activity will move across the Leeward Islands
through early this evening, and will be attended by strong gusty
winds. Other isolated shower activity moving rapidly westward in
moderate to fresh moist easterly flow are seen S of 26N and W of
57W. This activity is moving over the waters between the Bahamas
and Cuba as well as across the Straits of Florida.

A weak cold front along a position from 31N76W to inland NE
Florida just S of Jacksonville, Florida as of 15Z will slowly sink
southward to near 29N and westward to the vicinity of Daytona
Beach by early this evening. The front is expected to become
stationary across the central Atlantic Wed through Thu. Scattered
showers and isolated thunderstorms along and within about 60 nm S
of this frontal W of 77W will continue rather active through
tonight as an upper level trough shifts eastward from the NE Gulf.
The next cold front is forecast to move over the NW forecast
waters by early on Sat morning.

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

$$
JA/ERA

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/13/2018 - 13:24
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Tue Feb 13 2018 Valid 141200Z - 151200Z The ongoing forecast is on track and no changes are needed. See discussion below for more details. ..Leitman.. 02/13/2018 .PREV DISCUSSION... /ISSUED 0154 AM CST Tue Feb 13 2018/ ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS on Day 2/Wednesday as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin through the period. Enhanced mid-level west-southwesterly winds of 50-65 kt will overspread the southern/central High Plains by Wednesday afternoon. At the surface, lee cyclogenesis is forecast across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will strengthen into generally the 15-25 mph range by early Wednesday afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours Wednesday afternoon, supporting widespread elevated conditions across this region where fuels are dry/dormant. There will be some potential for critical fire weather conditions where RH values can fall below 15%. But, this may occur on just a brief/spotty basis for northeastern NM into parts of the TX/OK Panhandles with mid/high-level cloudiness streaming eastward from the upper low potentially limiting surface heating slightly. Will defer possible introduction of a critical area to a later update pending greater confidence in sufficient coverage and duration of sub-15% RH values. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/13/2018 - 13:24
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Tue Feb 13 2018 Valid 141200Z - 151200Z The ongoing forecast is on track and no changes are needed. See discussion below for more details. ..Leitman.. 02/13/2018 .PREV DISCUSSION... /ISSUED 0154 AM CST Tue Feb 13 2018/ ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS on Day 2/Wednesday as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin through the period. Enhanced mid-level west-southwesterly winds of 50-65 kt will overspread the southern/central High Plains by Wednesday afternoon. At the surface, lee cyclogenesis is forecast across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will strengthen into generally the 15-25 mph range by early Wednesday afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours Wednesday afternoon, supporting widespread elevated conditions across this region where fuels are dry/dormant. There will be some potential for critical fire weather conditions where RH values can fall below 15%. But, this may occur on just a brief/spotty basis for northeastern NM into parts of the TX/OK Panhandles with mid/high-level cloudiness streaming eastward from the upper low potentially limiting surface heating slightly. Will defer possible introduction of a critical area to a later update pending greater confidence in sufficient coverage and duration of sub-15% RH values. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/13/2018 - 11:57

000
AXNT20 KNHC 131756
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1256 PM EST Tue Feb 13 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
1745 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight gradient between a strong
surface ridge over the N Atlantic Ocean and lower pressure in
northern South America will continue to support gale-force winds
near the coast of Colombia during the night time hours through
Sat. Seas associated with these gale conditions are forecast to be
14 to 18 ft, subsiding some late in the week. 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 southwestward from the coast of
Africa near 05N10W and crosses the equator near 19W. The ITCZ is
located to the S of the equator. Scattered moderate isolated
strong convection is within 120 nm S and 30 nm N of the axis
between 10W-12W. Similar is well S of the axis within 30 nm
of a line from 01N02W to 01N05W to 01N10W.

...DISCUSSION...

GULF OF MEXICO...

A cold front extends from the western Atlantic to inland NE
Florida where it becomes stationary southwestward to 29N88W
and a warm front from there to 27N94W to 26N96W S to 23N96W. It
transitions back to a stationary front again to inland the coast
of Mexico near Coatzacoalcos. A trough is ahead of the frontal
boundary from 23N93W to inland Mexico just W of Nuevo Progreso,
while another trough extends from just W of the front near 25N95W
northwestward to just S of Corpus Christi, Texas. Isolated showers
and thunderstorms moving northward are NW of the warm front
between 90W-95W. Patches of rain and isolated thunderstorms are
W of the stationary portion in the SW and far W central portions
of the gulf. Isolated showers in very moist moderate to fresh E
flow are over portions of the eastern gulf and Straits of Florida.
High pressure W of the front is surging southward over the NW
Gulf and across eastern Mexico. Strong northerly winds are S of
21N near the coast of Mexico. Moist southerly flow moving over the
NE Gulf ahead of the front in response to a mid to upper level
trough sliding eastward across the NE Gulf is producing widespread
showers north of 25N east of the trough. The warm front will
weaken as it slowly lifts northward as a warm front through
early on Wed.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details
about the gale-force winds expected near the coast of Colombia.

Satellite water vapor imagery shows dry and stable atmospheric
conditions across the basin. Fast westward moving shallow trade
wind showers, with gusty winds, are observed over much of the
basin, except in the lee of Cuba and waters between Haiti and 76W
and to the S of 13N between Colombia and 77W. The shower activity
is more prevalent N of 12N and E of 71W to across the Lesser
Antilles. Surface observations during the morning and early
afternoon hours indicated strong wind gusts with these showers as
they passed across the Leeward Islands and northern portion of
the Windward Islands. The island of Dominica reported a wind gust
to 34 kt at 16Z as a light shower went by. A strong ridge N of the
area anchored by a 1033 mb high over the central Atlc near 32N53W
extends across the northern half of the Caribbean, with the
associated pressure gradient supporting fresh to strong trade
winds east of 80W. Seas are 14 to 18 ft near Colombia and 8 to 12
ft elsewhere. Strong winds are also occurring through the Atlc
passages, and are expected to continue through at least Wed.

ATLANTIC OCEAN...

Broad surface high pressure over the area is associated with a
1033 mb centered over the N central Atlantic near 32N53W and
moving southwestward is supporting fresh to strong E-NE winds
over most of the region, except close to the ridge axis N of 25N.
Isolated showers, moving quickly westward, are noted from 13N to
18N and to the W of 52W, including over much of the Leeward
Islands. This shower activity will move across the Leeward Islands
through early this evening, and will be attended by strong gusty
winds. Other isolated shower activity moving rapidly westward in
moderate to fresh moist easterly flow are seen S of 26N and W of
57W. This activity is moving over the waters between the Bahamas
and Cuba as well as across the Straits of Florida.

A weak cold front along a position from 31N76W to inland NE
Florida just S of Jacksonville, Florida as of 15Z will slowly sink
southward to near 29N and westward to the vicinity of Daytona
Beach by early this evening. The front is expected to become
stationary across the central Atlantic Wed through Thu. Scattered
showers and isolated thunderstorms along and within about 60 nm S
of this frontal W of 77W will continue rather active through
tonight as an upper level trough shifts eastward from the NE Gulf.
The next cold front is forecast to move over the NW forecast
waters by early on Sat morning.

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

$$
Aguirre
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/13/2018 - 10:04
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1002 AM CST Tue Feb 13 2018 Valid 131700Z - 141200Z The ongoing forecast is on track and no changes are needed. See discussion below for more details. ..Leitman.. 02/13/2018 .PREV DISCUSSION... /ISSUED 0154 AM CST Tue Feb 13 2018/ ...Synopsis... A closed upper low centered over CA/NV early this morning should develop only slowly southwestward through the period as an upstream shortwave trough approaches the Pacific Northwest. A broad belt of enhanced mid-level southwesterly flow will remain over the Southwest and southern/central Plains. At the surface, weak lee troughing is forecast to develop over the High Plains. ...Portions of the Southern/Central High Plains... Some disparity remains among short-term guidance regarding the strength of low-level winds today across parts of the southern and central High Plains. However, there is now enough of a signal for strong/gusty southwesterly winds around 15-20 mph this afternoon across parts of eastern NM into far southeastern CO, far southwestern KS, and the TX/OK Panhandles to include an elevated area. These surface winds would be mainly due to the enhanced mid-level flow present around 700-500 mb becoming mixed to the surface. RH values may become only marginally reduced to around 18-20% through peak heating, but this should still be sufficient to support elevated fire weather conditions across this region for a few hours in the afternoon. ...Portions of the Southwest... Locally strong/gusty southerly winds may occur this afternoon across parts of southeastern AZ into southern NM, with sustained wind speeds up to 15-20 mph. RH values may also become lowered to around 19-25% on an isolated basis across this area. However, the duration of these locally strong/gusty winds appears too limited in combination with the marginal reduction in RH values to warrant an elevated area at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/13/2018 - 08:44

000
AXNT20 KNHC 131444 CCA
TWDAT

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
705 AM EST Tue Feb 13 2018

Corrected surface analysis time

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 gradient between a strong
surface ridge over the north Atlantic Ocean and lower pressure
in northern South America will continue to support gale-force
winds near the coast of Colombia through Thu morning, then pulse
to minimal gale each night into the weekend. Seas associated with
these gale conditions are forecast to be 14 to 18 ft, subsiding
some late in the week. 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 southwestward from the coast of
Africa near 05N10W and crosses the equator near 19W. The ITCZ is
located to the S of the equator. Scattered moderate isolated
strong convection is within 60 nm S of the axis between 09W-12W.

...DISCUSSION...

GULF OF MEXICO...

A stationary front extends from just W of Apalachicola Florida to
27N91W, where it transitions to a warm front to 24N95W to 22N95W
and becomes a stationary front again to inland the coast of
Mexico near Coatzacoalcos. A trough is ahead of the frontal
boundary from 23N92W to inland Mexico just W of Nuevo Progreso,
while another trough extends from just W of the front near 25N95W
northwestward to near Brownsville, Texas. Scattered showers and
isolated thunderstorms are over portions of the NW and W central
sections of the Gulf of Mexico. Similar activity is noted along
and within 60 nm to the E of the trough that is ahead of the
front. Isolated showers in very moist moderate to fresh E flow are
over portions of the eastern gulf and Straits of Florida. High
pressure W of the front is surging southward over the NW Gulf and
across eastern Mexico. Strong northerly winds are S of 21N near
the coast of Mexico. Moist southerly flow moving over the NE Gulf
ahead of the front in response to a mid to upper level trough
sliding eastward across the NE Gulf is producing widespread
showers north of 25N east of the trough. The front will weaken
today, with the frontal remnants slowly lifting back northward as
a warm front through this evening.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details
about the gale-force winds expected near the coast of Colombia.

Satellite water vapor imagery shows dry and stable atmospheric
conditions across the basin. Patches of shallow trade wind
showers, moving rather quickly westward, are advecting westward
east of 75W, including the Lesser Antilles. A strong ridge N of
the area anchored by a 1033 mb high over the central Atlc near
32N53W extends across the northern half of the Caribbean, with the
associated pressure gradient supporting fresh to strong trade
winds east of 80W. Seas are 14 to 18 ft near Colombia and 8 to 12
ft elsewhere. Strong winds are also occurring through the Atlc
passages, and are expected to continue through at least Wed.

ATLANTIC OCEAN...

Broad surface high pressure over the area is associated with a
1033 mb centered over the N central Atlantic near 32N53W and
moving southwestward is supporting fresh to strong E-NE winds
over most of the region, except close to the ridge axis N of 25N.
Isolated trade wind showers, moving quickly westward, are noted
from 14N to 20N and to the W of 52W, including over much of the
Leeward Islands. This shower activity will move across the Leeward
Islands through late this afternoon or early this evening. Other
isolated shower activity moving rapidly westward in moderate to
fresh moist easterly flow are seen S of 26N and W of 57W. This
activity is moving over the waters between the Bahamas and Cuba
as well as across the Straits of Florida.

A cold front along 31N and W of 76W as of 09Z will approach 30N
Tue night, then become stationary across the central Atlantic Wed
and Thu. Scattered showers and isolated thunderstorms along and
within about 60 nm S of this frontal W of 77W will continue rather
active through tonight as an upper level trough shifts eastward
from the NE Gulf. The next cold front is forecast to move over
the NW forecast waters by early on Sat morning.

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

$$
Mundell/Aguirre
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Tue, 02/13/2018 - 06:05

000
AXNT20 KNHC 131205
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
705 AM EST Tue Feb 13 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
1145 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: A tight gradient between a strong
surface ridge over the north Atlantic Ocean and lower pressure
in northern South America will continue to support gale-force
winds near the coast of Colombia through Thu morning, then pulse
to minimal gale each night into the weekend. Seas associated with
these gale conditions are forecast to be 14 to 18 ft, subsiding
some late in the week. 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 southwestward from the coast of
Africa near 05N10W and crosses the equator near 19W. The ITCZ is
located to the S of the equator. Scattered moderate isolated
strong convection is within 60 nm S of the axis between 09W-12W.

...DISCUSSION...

GULF OF MEXICO...

A stationary front extends from just W of Apalachicola Florida to
27N91W, where it transitions to a warm front to 24N95W to 22N95W
and becomes a stationary front again to inland the coast of
Mexico near Coatzacoalcos. A trough is ahead of the frontal
boundary from 23N92W to inland Mexico just W of Nuevo Progreso,
while another trough extends from just W of the front near 25N95W
northwestward to near Brownsville, Texas. Scattered showers and
isolated thunderstorms are over portions of the NW and W central
sections of the Gulf of Mexico. Similar activity is noted along
and within 60 nm to the E of the trough that is ahead of the
front. Isolated showers in very moist moderate to fresh E flow are
over portions of the eastern gulf and Straits of Florida. High
pressure W of the front is surging southward over the NW Gulf and
across eastern Mexico. Strong northerly winds are S of 21N near
the coast of Mexico. Moist southerly flow moving over the NE Gulf
ahead of the front in response to a mid to upper level trough
sliding eastward across the NE Gulf is producing widespread
showers north of 25N east of the trough. The front will weaken
today, with the frontal remnants slowly lifting back northward as
a warm front through this evening.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details
about the gale-force winds expected near the coast of Colombia.

Satellite water vapor imagery shows dry and stable atmospheric
conditions across the basin. Patches of shallow trade wind
showers, moving rather quickly westward, are advecting westward
east of 75W, including the Lesser Antilles. A strong ridge N of
the area anchored by a 1033 mb high over the central Atlc near
32N53W extends across the northern half of the Caribbean, with the
associated pressure gradient supporting fresh to strong trade
winds east of 80W. Seas are 14 to 18 ft near Colombia and 8 to 12
ft elsewhere. Strong winds are also occurring through the Atlc
passages, and are expected to continue through at least Wed.

ATLANTIC OCEAN...

Broad surface high pressure over the area is associated with a
1033 mb centered over the N central Atlantic near 32N53W and
moving southwestward is supporting fresh to strong E-NE winds
over most of the region, except close to the ridge axis N of 25N.
Isolated trade wind showers, moving quickly westward, are noted
from 14N to 20N and to the W of 52W, including over much of the
Leeward Islands. This shower activity will move across the Leeward
Islands through late this afternoon or early this evening. Other
isolated shower activity moving rapidly westward in moderate to
fresh moist easterly flow are seen S of 26N and W of 57W. This
activity is moving over the waters between the Bahamas and Cuba
as well as across the Straits of Florida.

A cold front along 31N and W of 76W as of 09Z will approach 30N
Tue night, then become stationary across the central Atlantic Wed
and Thu. Scattered showers and isolated thunderstorms along and
within about 60 nm S of this frontal W of 77W will continue rather
active through tonight as an upper level trough shifts eastward
from the NE Gulf. The next cold front is forecast to move over
the NW forecast waters by early on Sat morning.

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

$$
Mundell/Aguirre
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/13/2018 - 01:56
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CST Tue Feb 13 2018 Valid 141200Z - 151200Z ...Synopsis... A closed upper low off the coast of southern CA will become absorbed within a southern stream jet across much of the southern/central CONUS on Day 2/Wednesday as an upstream perturbation moves southeastward from the Pacific Northwest to the Great Basin through the period. Enhanced mid-level west-southwesterly winds of 50-65 kt will overspread the southern/central High Plains by Wednesday afternoon. At the surface, lee cyclogenesis is forecast across the central High Plains as large-scale ascent preceding the previously mentioned upper low moves across this region. A surface trough will extend southward from the low across the southern High Plains, and the pressure gradient is forecast to strengthen through the day over these areas. ...Portions of the Southern/Central High Plains... Sustained west-southwesterly winds will strengthen into generally the 15-25 mph range by early Wednesday afternoon from parts of eastern NM into southeastern CO, southwestern KS, the TX/OK Panhandles, and northwestern OK as the enhanced mid-level winds mentioned above reach the surface through diurnal mixing/heating of the boundary layer. Higher gusts to 35-40 mph may occur. As temperatures warm well above normal (into the 70s), RH values will fall into mainly the 15-20% range for at least a few hours Wednesday afternoon, supporting widespread elevated conditions across this region where fuels are dry/dormant. There will be some potential for critical fire weather conditions where RH values can fall below 15%. But, this may occur on just a brief/spotty basis for northeastern NM into parts of the TX/OK Panhandles with mid/high-level cloudiness streaming eastward from the upper low potentially limiting surface heating slightly. Will defer possible introduction of a critical area to a later update pending greater confidence in sufficient coverage and duration of sub-15% RH values. ..Gleason.. 02/13/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Tue, 02/13/2018 - 01:55
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0154 AM CST Tue Feb 13 2018 Valid 131200Z - 141200Z ...Synopsis... A closed upper low centered over CA/NV early this morning should develop only slowly southwestward through the period as an upstream shortwave trough approaches the Pacific Northwest. A broad belt of enhanced mid-level southwesterly flow will remain over the Southwest and southern/central Plains. At the surface, weak lee troughing is forecast to develop over the High Plains. ...Portions of the Southern/Central High Plains... Some disparity remains among short-term guidance regarding the strength of low-level winds today across parts of the southern and central High Plains. However, there is now enough of a signal for strong/gusty southwesterly winds around 15-20 mph this afternoon across parts of eastern NM into far southeastern CO, far southwestern KS, and the TX/OK Panhandles to include an elevated area. These surface winds would be mainly due to the enhanced mid-level flow present around 700-500 mb becoming mixed to the surface. RH values may become only marginally reduced to around 18-20% through peak heating, but this should still be sufficient to support elevated fire weather conditions across this region for a few hours in the afternoon. ...Portions of the Southwest... Locally strong/gusty southerly winds may occur this afternoon across parts of southeastern AZ into southern NM, with sustained wind speeds up to 15-20 mph. RH values may also become lowered to around 19-25% on an isolated basis across this area. However, the duration of these locally strong/gusty winds appears too limited in combination with the marginal reduction in RH values to warrant an elevated area at this time. ..Gleason.. 02/13/2018 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Mon, 02/12/2018 - 23:40

000
AXNT20 KNHC 130540
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
105 AM EST Tue Feb 13 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 gradient between a strong
surface ridge over the north Atlantic Ocean and lower pressure
in northern South America will continue to support gale-force
winds near the coast of Colombia through Thursday morning, then
pulse to minimal gale each night into the weekend. Please read
the latest NHC High Seas Forecast under AWIPS/WMO headers
MIAHSFAT2/FZNT02 KNHC for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends southwest from the coast of Africa
near 05N10W and crosses the equator near 19W. The ITCZ is south
of the equator. Scattered moderate convection is within 60 nm S
of the axis between 11W-14W.

...DISCUSSION...

GULF OF MEXICO...

A stationary front extends from the western panhandle of Florida
to the Bay of Campeche. A ridge is across eastern Mexico and the
NW Gulf behind the front. Strong northerly winds are S of 21N
near the coast of Mexico. Moist southerly flow moving northward
in the NE Gulf ahead of the front in response to a mid to upper
level trough sliding eastward across the NE Gulf is producing
widespread showers north of 25N east of the trough. The front
will weaken overnight, with the frontal remnants slowly lifting
back north as a warm front on Tue.

CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section above for details
about the gale-force winds expected near the coast of Colombia.

Water vapor imagery shows dry and stable atmospheric conditions
across the basin. Patches of shallow trade wind showers are
advecting westward east of 75W, including the Lesser Antilles. A
strong ridge N of the area anchored by a 1036 mb high in the
central Atlc extends across the northern half of the Caribbean,
with the associated pressure gradient supporting fresh to strong
trade winds east of 80W. Seas are 12-15 ft near Colombia and 8
to 12 ft elsewhere. Strong winds are also occurring through the
Atlc passages, and are expected to continue through mid-week.

ATLANTIC OCEAN...

Broad surface high pressure over the area is associated with a
1036 mb high centered over the N central Atlantic is supporting
fresh to strong E-NE winds over most of the region, except close
to the ridge axis north of 25N. Isolated trade wind showers are
noted from 15N to 25N and between 40W and 60W. Shower activity
should move across the Leeward Islands later tonight through Tue
night.

A cold front moving off the U.S. east coast will approach 30N
Tue night, then become stationary across the central Atlantic
Wed and Thu. Scattered showers are expected to develop along and
ahead of the frontal boundary north of 30N through Tue night as
an upper level trough shifts eastward from the NE Gulf. The next
cold front is forecast to enter the NW forecast waters by early
Saturday morning.

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

$$
Mundell
Categories: Weather

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