Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Sat, 11/18/2017 - 04:17

000
AXNT20 KNHC 181017
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
517 AM EST Sat Nov 18 2017

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
1015 UTC.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 09N13W to
08N20W. The Intertropical Convergence Zone axis extends from
08N20W to 06N24W to 08N36W, then resumes west of a surface trough
near 07N40W to the South American coast near 07N58W. Isolated
moderate convection is from 04N-11N between 12W-24W. Scattered
moderate convection is from 08N-11N between 38W-45W.

...DISCUSSION...

GULF OF MEXICO...

A 1021 mb high is centered over North Carolina near 35N78W. A
surface ridge axis extends SW from the high to the central Gulf of
Mexico near 25N90W. 10-15 kt surface winds are over the base of
the ridge axis. Radar imagery shows isolated showers over the
Straits of Florida between 81W-83W. Fair weather is over the
remainder of the Gulf of Mexico. In the upper levels, a large
upper level high is centered over central Mexico near 23N102W
producing northerly upper level flow and strong subsidence over
the entire Gulf of Mexico. The next cold front is expected to
emerge off the Texas and Louisiana coasts Saturday evening with
showers. 25-30 kt N-NE winds will follow in the wake of the front
as it sweeps southeastward.

CARIBBEAN SEA...

A surface trough extends from Hispaniola at 20N70W to N Colombia
at 07N75W. Two 1008 mb lows are embedded on the trough axis at
18N72W and 11N74W. Scattered showers and clusters of scattered
moderate convection are within 360 nm E of the trough axis, to
include Puerto Rico. In the upper levels, an upper level trough is
over the NW Caribbean with axis from central Cuba near 22N80W to
the Gulf of Honduras near 16N89W. Upper level diffluence E of the
trough is enhancing the showers and convection over the central
Caribbean Sea. Expect the area of convection to drift E and
persist for the next 48 hours.

...HISPANIOLA...

Scattered showers are over the island, and will continue through
the weekend. Expect convection to be heaviest over E Hispaniola
in the afternoon and evening hours during maximum heating.
Localized flooding is also possible during this time.

ATLANTIC OCEAN...

A 1007 mb low is centered over the central Atlantic near 26N57W.
A surface trough extends SW from the low to Hispaniola near
20N70W. Scattered moderate to isolated strong convection is N of
the Leeward Islands from 19N-23N between 59W-67W. Scattered
showers are elsewhere within 120 nm of the trough. A quasi-
stationary front enters the central Atlantic near 31N38W and
extends to 27N50W to the central Atlantic low near 26N57W.
Scattered showers are within 120 nm of the frontal system. A 1019
mb high is centered over the E Atlantic near 27N28W. Of note in
the upper levels, a large upper level trough is over the W
Atlantic enhancing the central Atlantic with upper level
diffluence. Another upper level trough is over Morocco.

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

$$
Formosa

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Sat, 11/18/2017 - 01:51
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0148 AM CST Sat Nov 18 2017 Valid 191200Z - 201200Z ...Synopsis... A broad mid-level ridge will take hold across much of the western half of the country on Sunday in the wake of a fast-moving, mid-level trough. At the surface, high pressure will be located across the Great Basin, with a secondary high pressure center located over southern Texas. In between, weak lee troughing will begin to take hold across the High Plains. ...Southern Plains... Southerly winds will increase in response to a tightening surface-pressure gradient. Relative humidity will fall in the upper-teens to near thirty percent during the afternoon. The result will be elevated fire-weather conditions for a few hours during Sunday afternoon. However, temperatures in the mid-50s to mid-60s should mitigate a larger-scale fire-weather threat. ..Marsh.. 11/18/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Sat, 11/18/2017 - 01:50
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0148 AM CST Sat Nov 18 2017 Valid 181200Z - 191200Z ...Synopsis... A strong mid-level trough will continue to move across the United States today. In the wake of this trough, cooler and drier conditions will overspread much of the western two-thirds of the United States as a surface high pressure moves into the Great Basin. The position of the high will result in north/northeasterly winds across portions of Southern California both this morning and Sunday morning, with a diurnally driven decrease in winds in between. The offshore flow will result in elevated fire-weather conditions primarily across the mountains of Santa Barbara, Ventura, and Los Angeles counties. Elsewhere, strong gusty northerly winds will overspread portions of the southern Plains in the wake of a surface cold front. Cooler conditions will result in slightly higher relative humidity today as compared to Friday. The higher relative humidity and cooler conditions should limit the overall fire-weather threat despite the strong, gusty surface winds. ..Marsh.. 11/18/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 11/17/2017 - 23:18

000
AXNT20 KNHC 180518
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1218 AM EST Sat Nov 18 2017

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.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 09N13W to
06N26W. The Intertropical Convergence Zone axis extends from
06N26W to 07N36W, then resumes west of a surface trough near
07N39W to 06N46W to the South American coast near 07N58W.
Scattered moderate convection is from 04N-10N E of 24W, and
from 08N-11N between 30W-46W.

...DISCUSSION...

GULF OF MEXICO...

A 1023 mb high is centered over North Carolina near 35N77W. A
surface ridge axis extends SW from the high to the central Gulf
of Mexico near 25N90W. 10-15 kt surface winds are over the base
of the ridge axis. Radar imagery shows scattered showers over the
Straits of Florida between 81W-83W. Mostly fair weather is over
the remainder of the Gulf of Mexico. In the upper levels, a large
upper level high is centered over central Mexico near 23N102W
producing northerly upper level flow and strong subsidence over
the entire Gulf of Mexico. The next cold front is expected to
emerge off the Texas and Louisiana coasts Saturday evening with
showers. 25-30 kt N-NE winds will follow in the wake of the front
as it sweeps southeastward.

CARIBBEAN SEA...

A surface trough extends from Hispaniola at 20N70W to N Colombia
at 09N75W. Two 1008 mb lows are embedded on the trough axis at
18N73W and 11N75W. Scattered showers and clusters of scattered
moderate convection are within 360 nm E of the trough axis, to
include Puerto Rico. In the upper levels, an upper level trough
is over the NW Caribbean with axis from central Cuba near 22N80W
to the Gulf of Honduras near 16N89W. Upper level diffluence E of
the trough is enhancing the showers and convection over the
central Caribbean Sea. Expect the area of convection to drift E
and persist for the next 48 hours.

...HISPANIOLA...

Scattered showers and thunderstorms are over the island, and will
continue through the weekend. Convection will likely be heaviest
over E Hispaniola in the afternoon and evening hours during
maximum heating. Localized flooding and life-threatening mud
slides are also possible during this time.

ATLANTIC OCEAN...

The tail end of a dissipating cold front is over the W Atlantic
from 31N64W to 27N71W. Scattered showers are within 45 nm of the
front. A 1009 mb low is centered over the central Atlantic near
26N59W. A surface trough extends SW from the low to Hispaniola
near 20N70W. Scattered moderate to isolated strong convection is N
of the Leeward Islands from 20N-23N between 60W-68W. Scattered
showers are elsewhere within 120 nm of the trough. A cold front
enters the central Atlantic near 31N40W and extends to 27N46W. A
stationary front continues to the central Atlantic low near
26N59W. Scattered showers are within 120 nm of the frontal system.
A 1018 mb high is centered over the E Atlantic near 27N27W. Of
note in the upper levels, a large upper level trough is over the W
Atlantic supporting the W Atlantic front, and enhancing the
central Atlantic with upper level diffluence. Another upper level
trough is over Morocco.

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

$$
Formosa

Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 11/17/2017 - 18:03

000
AXNT20 KNHC 180003
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
703 PM EST Fri Nov 17 2017

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.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 10N15W to
07N21W. The Intertropical Convergence Zone axis extends from
07N21W to 07N34W, then resumes west of a surface trough near
06N38W to 04N52W. Scattered moderate convection is from 07N-10N E
of 16W.

...DISCUSSION...

GULF OF MEXICO...

Stable conditions prevail basin-wide being supported by deep
layered dry air and a broad surface ridge anchored near West
Virginia that extends SSW into the Gulf. This ridge provides NE to
E light to moderate flow E of 90W and E to SE winds of the same
magnitude W of 90W. The next cold front is expected to emerge off
the Texas and Louisiana coasts by Saturday night followed by
strong to near-gale N-NE winds. Scattered to isolated showers are
expected in the vicinity of the front as it moves southeastward
through Monday.

CARIBBEAN SEA...

A pair of lows prevail in the central Caribbean underneath a broad
upper level ridge covering the eastern half of the basin. The
northern low is 1008 mb and is located over S Haiti adjacent
waters near 17N73W. The second low is 1009 mb and is off the coast
of Colombia near 12N75W. Upper level diffluence between an upper
trough over the western basin and the ridge to the east supports
scattered showers and tstms N of 15N between 67W and 73W and S of
13N between 71W and 79W. Otherwise, moderate to occasional fresh
northerly winds are noted across the western Caribbean waters
generally W of 78W while ESE light to moderate wind flow is E of
the the area of low pressure. The low is expected to remain
nearly stationary S of Hispaniola and gradually dissipate by
Monday.

...HISPANIOLA...

Scattered showers and tstms are across the eastern half of the
island while isolated showers are elsewhere. This activity is
being supported by an elongated area of low pressure in the
Central Caribbean extending beyond Hispaniola into the SW N Atlc
waters. Upper level diffluence supports this convection as well.
Similar shower activity will continue during the weekend into
Monday as the area of low pressure S of the island will stall
before dissipating early next week.

ATLANTIC OCEAN...

The SW North Atlc is under the influence of a relatively dry
middle to upper level trough that supports a cold front N of the
area with tail dissipating along 30N66W to 27N72W. A middle level
trough and upper level diffluence supports scattered showers and
tstms N of Hispaniola and Puerto Rico to 24N. North-northeast of
that area of convection, a stationary front extends from 30N40W to
27N50W to a 1009 mb low near 25N61W. Scattered showers are N of
the low between 50W and 65W. Surface ridging is elsewhere in the
central and eastern Atlc being anchored by a 1018 mb high near
27N31W.

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

$$
Ramos
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 11/17/2017 - 11:18

000
AXNT20 KNHC 171718
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1218 PM EST Fri Nov 17 2017

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
1545 UTC.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 09N13W to
06N24W to 07N30W. The Intertropical Convergence Zone axis extends
from 07N30W to 08N38W to 05N52W. Widely scattered moderate
convection is from 03N-13N between 18W-42W.

...DISCUSSION...

GULF OF MEXICO...
NW flow aloft prevails over the Gulf basin this afternoon on the
western periphery of an upper level trough extending over the SW
North Atlc...southern Florida peninsula...and base over southern
Mexico. Mostly stable conditions are noted at the surface as a
ridge axis extends from an Ohio River valley anchored 1027 mb high
near 40N81W S-SW to the lower Mississippi River valley into the SW
Gulf near 21N95W. Skies are mostly clear with the exception of a
few possible isolated showers within 60 nm either side of a
surface trough analyzed from 18N94W to 23N98W. Otherwise...gentle
to moderate anticyclonic winds are forecast through early Friday
night. The next cold front is expected to emerge off the Texas
and Louisiana coasts by late Saturday into Saturday night. Fresh
to strong N-NE winds will follow in wake of the front as it sweeps
southeastward through Sunday night into early Monday.

CARIBBEAN SEA...
A broad area of lower pressure across the basin continues to be
focused on a 1008 mb low centered SW of Hispaniola near 17N73W. A
surface trough extends SW from the low to near 11N77W and links up
with the monsoon trough axis along 09N/10N supporting scattered
showers and strong tstms from 09N-18N between 68W-79W.
Otherwise...moderate to occasional fresh northerly winds are
noted across the western Caribbean waters generally W of
77W...while trade wind flow E of the surface troughing will
continue to be disrupted outside of convection...with gentle to
moderate southerly winds prevailing this afternoon through the
upcoming weekend. The low is expected to remain nearly stationary
SW of Hispaniola and gradually dissipate by Monday.

...HISPANIOLA...
Widely scattered showers and isolated tstms are expected to
persist across the island the next few days as deep moisture and
cloudiness advects NE over the region due to an upper trough to
the NW over the SW North Atlc and SE Gulf of Mexico. Convection
will likely be more widespread in areal coverage during the
afternoon and evening hours due to maximum heating and
instability.

ATLANTIC OCEAN...
The SW North Atlc is under the influence of an relatively dry
middle to upper level trough with axis extending from 32N75W to
over the Florida Straits to a base over southern Mexico. However a
cold front primarily analyzed N of the discussion area extends
from 32N68W to 30N73W providing possible isolated showers from
26N-32N between the front and 65W. More active weather lies to
the SE as the upper level troughing has continued to support
another cold front entering the discussion area across the central
Atlc. The cold front extends from 32N41W SW to 27N51W becoming
stationary into a 1009 mb low centered near 24N64W. Weak surface
troughing then continues W-SW to the coast of Hispaniola near
20N72W and into the central Caribbean Sea. Scattered showers and
widely scattered tstms are occurring across a large area in the
vicinity of the troughing and stationary front from 20N-29N
between 51W-74W. Other widely scattered showers and isolated tstms
are occurring in association with the cold front from 25N-32N
between 32W-47W. The frontal troughing is expected to persist
across the central Atlc through Saturday night as ridging builds
in off the SE CONUS and into the SW North Atlc. Finally...mostly
tranquil conditions are noted across the eastern Atlc in the
vicinity of a 1018 mb high centered near 28N29W...however a
surface trough extends from a weakening 1014 mb low centered SE of
the Azores to near 27N23W. Possible isolated showers are N of 27N
between 15W-21W...including the Canary Islands.

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

$$
HUFFMAN

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Fri, 11/17/2017 - 10:57
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1056 AM CST Fri Nov 17 2017 Valid 181200Z - 191200Z ...Mountains and Foothills of Southern CA... A few hours of elevated fire weather conditions are anticipated across the region early Saturday morning, primarily across the mountains of Santa Barbara, Ventura, and Los Angeles counties. Offshore gradient will decrease diurnally before increasing again Saturday night/Sunday morning. Winds are expected to be slightly weaker Saturday night/Sunday morning than Saturday morning but poor overnight recovery will likely still result in elevated fire weather conditions over the mountains and foothills of Santa Barbara, Ventura, and Los Angeles counties. ..Mosier.. 11/17/2017 .PREV DISCUSSION... /ISSUED 0147 AM CST Fri Nov 17 2017/ ...Synopsis... Northerly surface winds will be ongoing across southern California at the start of the forecast period. These winds will act to help dry out fine fuels across the area. By mid-to-late morning, the Santa Ana winds are anticipated to weaken, ending this low-end elevated fire-weather threat. Overnight Saturday into Sunday, northerly surface winds are expected to develop once again. These winds will usher in a cooler/drier airmass. By afternoon, minimum relative humidity will fall to the 5-15 percent range; however, surface winds will be decreasing by this time. Because the strongest surface winds and lowest relative-humidity values will be out of phase, critical fire-weather conditions do not appear likely. Thus, elevated fire-weather highlights will be introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Fri, 11/17/2017 - 10:57
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1056 AM CST Fri Nov 17 2017 Valid 181200Z - 191200Z ...Mountains and Foothills of Southern CA... A few hours of elevated fire weather conditions are anticipated across the region early Saturday morning, primarily across the mountains of Santa Barbara, Ventura, and Los Angeles counties. Offshore gradient will decrease diurnally before increasing again Saturday night/Sunday morning. Winds are expected to be slightly weaker Saturday night/Sunday morning than Saturday morning but poor overnight recovery will likely still result in elevated fire weather conditions over the mountains and foothills of Santa Barbara, Ventura, and Los Angeles counties. ..Mosier.. 11/17/2017 .PREV DISCUSSION... /ISSUED 0147 AM CST Fri Nov 17 2017/ ...Synopsis... Northerly surface winds will be ongoing across southern California at the start of the forecast period. These winds will act to help dry out fine fuels across the area. By mid-to-late morning, the Santa Ana winds are anticipated to weaken, ending this low-end elevated fire-weather threat. Overnight Saturday into Sunday, northerly surface winds are expected to develop once again. These winds will usher in a cooler/drier airmass. By afternoon, minimum relative humidity will fall to the 5-15 percent range; however, surface winds will be decreasing by this time. Because the strongest surface winds and lowest relative-humidity values will be out of phase, critical fire-weather conditions do not appear likely. Thus, elevated fire-weather highlights will be introduced. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Fri, 11/17/2017 - 10:53
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1052 AM CST Fri Nov 17 2017 Valid 171700Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO INTO THE CENTRAL TEXAS PANHANDLE... ...Southern High Plains... Widespread elevated fire weather conditions are still anticipated for a few hours this afternoon as increasing mid-level flow coupled with deep boundary layer mixing and a strengthening surface pressure gradient combine to support sustained winds from 20 to 30 mph. High temperatures across the region will range from the mid 70s to upper 80s (15 to 25 degree above-average), supporting afternoon RH values in from the low teens to mid 20s. Highest confidence in critical conditions remains from east-central NM northeastward into the central TX Panhandle. Near-critical conditions are anticipated farther south/southwest into southern NM with slightly weaker winds (sustained around 15 to 20 mph) precluding critical meteorological conditions. As mentioned in the previous discussion, fuels do not appear particularly receptive but given the strength of the winds and the anomalously warm temperatures, a widespread elevated to locally critical fire weather threat still exists. ..Mountains and Foothills of Southern CA... Current onshore gradient is expected shift offshore tonight as a front moves through the Great Basin and high surface pressure follows in its wake. Guidance indicates that the LAX-DAG and LAX-TPH gradients will be around -6 mb and -10 mb, respectively, by 12Z Saturday. Gradients of this strength will likely support wind gusts from 35-40 mph. RH values are expected to remain above critical thresholds across most of the region but some locally elevated fire weather conditions are still anticipated for a few hours early Saturday morning. ..Mosier.. 11/17/2017 .PREV DISCUSSION... /ISSUED 0147 AM CST Fri Nov 17 2017/ ...Synopsis... Strong mid-level flow will develop across the southern Plains on Friday as a mid-level trough quickly moves east into the central United States. This strong mid-level flow will result in downslope warming/drying across the southern Plains. Here, widespread temperatures in the mid-70s to mid-80s will combine with poor low-level moisture to result in minimum afternoon relative-humidity values falling into the teens in some locations. These warm/dry conditions will combine with surface-wind speeds gusting into the 20-30 mph range to support elevated-to-critical fire-weather conditions. The most likely area for critical conditions will be from east-central New Mexico into the central Texas Panhandle, where surface winds around 30 mph sustained in the presence of mid-teen relative humidity. One potential mitigating factor is that ERCs are generally near or below the 50th percentile across the region, which may preclude a more widespread, larger-scale fire-weather threat. Late in the period (Saturday morning), north/north-east winds will develop across coastal areas of southern California. These weak Santa Ana winds may gust near 40-45 mph in wind favored areas. These strong winds will help dry out finer fuels. However, even with the drying, relative humidity looks to remain high enough to preclude elevated highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 11/17/2017 - 04:29

000
AXNT20 KNHC 171029
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
529 AM EST Fri Nov 17 2017

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
1015 UTC.

...SPECIAL FEATURES...

A 993 mb low is centered near 40N41W with an associated cold
front extending SW from the low to 37N39W to 31N44W. A surface
trough continues SW from 31N44W to 27N53W. The low is supported
aloft by an upper level trough between 35W-55W N of 30N. In
forecast waters, gale force S-SW winds are N of 29N E of the
trough between 41W-43W, with seas from 10-16 ft. See the latest
NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02
KNHC for more details.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 10N14W to
06N23W to 06N28W. The Intertropical Convergence Zone axis extends
from 06N28W to 04N38W to the South American coast near 06N54W.
Isolated moderate convection is from 04N-11N E of 42W.

...DISCUSSION...

GULF OF MEXICO...

A 1025 mb high is centered over Ohio near 40N84W. A surface ridge
axis extends S from the high to the central Gulf of Mexico near
26N90W. 10-15 kt surface winds are over the base of the ridge
axis. A surface trough is over the Bay of Campeche from 21N94W to
17N94W. Scattered showers are S of 21N between 92W-97W.
Elsewhere, radar imagery shows scattered showers and isolated
thunderstorms over the Straits of Florida and W Cuba from 23N-25N
between 80W-82W. Mostly fair weather is over the remainder of the
Gulf of Mexico. In the upper levels, a large upper level trough
is over the Gulf with axis from N Florida at 30N80W to the Yucatan
Peninsula at 20N90W. Very strong subsidence is over the Gulf. The
next cold front is expected to emerge off the Texas and Louisiana
coasts Saturday evening with showers. 25-30 kt N-NE winds will
follow in the wake of the front as it sweeps southeastward.

CARIBBEAN SEA...

A surface trough extends from Hispaniola at 20N70W to Panama at
09N79W. Two 1008 mb lows are embedded on the trough axis at
17N73W and 13N76W. Scattered showers and clusters of scattered
moderate convection are within 420 nm E of the trough axis. In the
upper levels, upper level diffluence E of the Gulf of Mexico
trough is enhancing the showers and convection over the Caribbean
Sea. Expect conditions to persist for the next 48 hours.

...HISPANIOLA...

Scattered showers and thunderstorms are over the island, and will
continue through the weekend, as deep moisture advects NE over
the region due to the upper level trough. Convection will likely
be heaviest in the afternoon and evening hours during maximum
heating. Localized flooding and life-threatening mud slides are
also possible during this time.

ATLANTIC OCEAN...

The tail end of a dissipating cold front is over the W Atlantic
from 31N70W to 27N74W. A trough extends from 26N73W through the
central Bahamas to central Cuba at 23N80W. Scattered showers are
within 45 nm of the trough. Another surface trough is N of the
Leeward Islands from 25N62W to Hispaniola at 20N70W. Scattered
showers and clusters of scattered moderate convection are within
360 nm E of the trough axis. A surface trough with gale winds are
over the central Atlantic. See above. Scattered showers and
clusters of scattered moderate convection are within 240 nm E of
this trough axis. A 1020 mb high is centered over the E Atlantic
near 28N30W. The tail end of a surface trough is over the E
Atlantic from 31N19W to 27N23W. Scattered moderate convection is
W of the Canary Islands from 28N-31N between 18W-20W. Of note in
the upper levels, a large upper level trough is over the W
Atlantic supporting the W Atlantic front, and enhancing the
central Atlantic with upper level diffluence. Another upper level
trough is over the E Atlantic supporting the E Atlantic surface
trough.

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

$$
Formosa

Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Fri, 11/17/2017 - 01:50
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Fri Nov 17 2017 Valid 181200Z - 191200Z ...Synopsis... Northerly surface winds will be ongoing across southern California at the start of the forecast period. These winds will act to help dry out fine fuels across the area. By mid-to-late morning, the Santa Ana winds are anticipated to weaken, ending this low-end elevated fire-weather threat. Overnight Saturday into Sunday, northerly surface winds are expected to develop once again. These winds will usher in a cooler/drier airmass. By afternoon, minimum relative humidity will fall to the 5-15 percent range; however, surface winds will be decreasing by this time. Because the strongest surface winds and lowest relative-humidity values will be out of phase, critical fire-weather conditions do not appear likely. Thus, elevated fire-weather highlights will be introduced. ..Marsh.. 11/17/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Fri, 11/17/2017 - 01:49
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Fri Nov 17 2017 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO INTO THE CENTRAL TEXAS PANHANDLE... ...Synopsis... Strong mid-level flow will develop across the southern Plains on Friday as a mid-level trough quickly moves east into the central United States. This strong mid-level flow will result in downslope warming/drying across the southern Plains. Here, widespread temperatures in the mid-70s to mid-80s will combine with poor low-level moisture to result in minimum afternoon relative-humidity values falling into the teens in some locations. These warm/dry conditions will combine with surface-wind speeds gusting into the 20-30 mph range to support elevated-to-critical fire-weather conditions. The most likely area for critical conditions will be from east-central New Mexico into the central Texas Panhandle, where surface winds around 30 mph sustained in the presence of mid-teen relative humidity. One potential mitigating factor is that ERCs are generally near or below the 50th percentile across the region, which may preclude a more widespread, larger-scale fire-weather threat. Late in the period (Saturday morning), north/north-east winds will develop across coastal areas of southern California. These weak Santa Ana winds may gust near 40-45 mph in wind favored areas. These strong winds will help dry out finer fuels. However, even with the drying, relative humidity looks to remain high enough to preclude elevated highlights. ..Marsh.. 11/17/2017 ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Fri, 11/17/2017 - 00:02

000
AXNT20 KNHC 170602
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
102 AM EST Fri Nov 17 2017

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...

A 996 mb low is centered near 38N44W with the associated cold
front extending SW from the low to 31N47W. A surface trough
continues SW from 31N44W to 26N58W. The low is supported aloft by
an upper level trough between 35W-55W N of 30N. In forecast
waters, gale force S-SW winds are N of 29N E of the trough between
43W-45W, with seas from 10-16 ft. See the latest NWS High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 08N13W to
06N27W. The Intertropical Convergence Zone axis extends from
06N27W to 08N40W to the South American coast near 08N51W. Isolated
moderate convection is from 04N-12N E of 43W.

...DISCUSSION...

GULF OF MEXICO...

A 1026 mb high is centered over Indiana near 40N87W. A surface
ridge axis extends S from the high to the central Gulf of Mexico
near 26N90W. 10-15 kt surface winds are over the base of the
ridge axis. A surface trough is over the Bay of Campeche from
22N93W to 18N93W. Scattered showers are S of 21N between 92W- 97W.
Elsewhere, radar imagery shows scattered showers and isolated
thunderstorms over the Straits of Florida and W Cuba from 23N-25N
between 80W- 82W. Mostly fair weather is over the remainder of the
Gulf of Mexico. In the upper levels, a large upper level trough
is over the Gulf with axis from N Florida at 30N80W to the Yucatan
Peninsula at 20N90W. Very strong subsidence is over the Gulf. The
next cold front is expected to emerge off the Texas and Louisiana
coasts Saturday evening with showers. 25-30 kt N-NE winds will
follow in the wake of the front as it sweeps southeastward.

CARIBBEAN SEA...

A surface trough extends from Haiti at 20N72W to W Panama at
09N82W. Two 1008 mb lows are embedded on the trough axis at 17N75W
and 14N78W. Scattered showers and clusters of scattered moderate
convection are within 420 nm E of the trough axis. In the upper
levels, upper level diffluence E of the Gulf of Mexico trough is
enhancing the showers and convection over the Caribbean Sea.
Expect conditions to persist for the next 48 hours.

...HISPANIOLA...

Scattered showers and thunderstorms are over the island, and will
continue through the weekend, as deep moisture advects NE over
the region due to the upper level trough. Convection will likely
be heaviest in the afternoon and evening hours during maximum
heating. Localized flooding and life-threatening mud slides are
also possible during this time.

ATLANTIC OCEAN...

The tail end of a dissipating cold front is over the W Atlantic
from 31N73W to the N Bahamas at 27N79W. A prefrontal trough
extends from 29N72W through the central Bahamas to central Cuba at
23N80W. Scattered showers are within 45 nm of the trough. Another
surface trough is over the W Atlantic from 24N65W to Haiti at
20N72W. Scattered showers and clusters of scattered moderate
convection are within 360 nm E of the trough axis. A surface
trough with gale winds are over the central Atlantic. See above.
Scattered showers and clusters of scattered moderate convection
are within 240 nm E of this trough axis. A 1019 mb high is
centered over the E Atlantic near 31N33W. The tail end of a
surface trough is over the E Atlantic from 31N20W to 28N24W.
Scattered moderate convection is W of the Canary Islands from N of
28N between 17W-21W. Of note in the upper levels, a large upper
level trough is over the W Atlantic supporting the W Atlantic
front, and enhancing the central Atlantic with upper level
diffluence. Another upper level trough is over the E Atlantic
supporting the E Atlantic surface trough.

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

$$
Formosa

Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Thu, 11/16/2017 - 18:03

000
AXNT20 KNHC 170002
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
702 PM EST Thu Nov 16 2017

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...

A 996 mb low is centered near 34N48W with the associated cold
front extending SW from the low to 31N50W. The low is supported
aloft by a middle to upper level trough with axis extending S to a
base near 30N. A surface trough follows the tail of the front
extending SW along 25N60W to the Windward Passage. Gale force
S-SW winds are N of 28.5N E of the trough to 46W with seas from 9
to 15 ft. See the latest NWS High Seas Forecast under AWIPS/WMO
headers MIAHSFAT2/FZNT02 KNHC for more details.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 08N13W to
07N27W. The Intertropical Convergence Zone axis extends from
07N27W to 07N40W to 06N53W. Scattered moderate convection is from
03N-15N E of 41W.

...DISCUSSION...

GULF OF MEXICO...

Generally, stable conditions prevail basin-wide being supported
by dry air subsidence from aloft and broad surface high pressure
anchored over Illinois state and extending SSW across the northern
half of the Gulf. This ridge provides NE light to moderate flow E
of 90W and NE-E light to gentle flow elsewhere. In the SW basin, a
surface trough extends from 22N92W to the Bay of Campeche near
17N94W with possible isolated showers. The next cold front is
expected to emerge off the Texas and Louisiana coasts Saturday
night. Fresh to strong N-NE winds will follow in wake of the front
as it sweeps southeastward.

CARIBBEAN SEA...

A middle level trough extends from the SW N Atlc SSW to a base
near Panama. This trough continues to support a 1007 mb low over
SW Haiti adjacent waters or to the SE of Jamaica near 17N74W. A
surface trough extends from the Windward Passage to the low to
09N80W. Scattered heavy showers and isolated tstms are S of 19N
between 67W-82W. Isolated showers are occurring across Hispaniola
and portions of Puerto Rico, the Windward Passage and the Mona
Channel. Otherwise, moderate to occasional fresh northerly winds
are noted across the western Caribbean waters generally W of 79W
while SW flow of the same magnitude is E of the low pressure
system to 71W. Variable light to gentle winds are elsewhere. The
low is expected to remain nearly stationary S-SW of Hispaniola
through early Monday.

...HISPANIOLA...

Scattered showers and tstms persist across the island and will
continue through the weekend as deep moisture advects NE over the
region due to a middle to upper level trough. Convection will
likely be heaviest in the afternoon and evening hours during
maximum heating. Localized flooding and life-threatening mud
slides are also possible during this time.

ATLANTIC OCEAN...

Aside from the special features section above highlighting the
area of low pressure and associated gale-force winds, the remnants of
a dissipating cold front are analyzed as a surface trough in the
SW N Atlc waters from 29N72W to 24N75W. The surface trough
associated with the region discussed in special features supports
scattered heavy showers and tstms N of Puerto Rico and Hispaniola
to 23N and isolated showers N of 23N between 50W-60W. Scattered
showers are N of 28N between 40W-50W. The frontal troughing is
expected to persist across the central Atlc through Saturday night
as ridging builds in off the SE CONUS and into the SW North Atlc.
Otherwise, surface ridging will prevail in the E Atlc.

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

$$
Ramos
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Thu, 11/16/2017 - 12:53
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1252 PM CST Thu Nov 16 2017 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO EASTWARD INTO PORTIONS OF THE TEXAS PANHANDLE... After coordination with affected local WFOs, decided on an upgrade to critical for a small part of east-central New Mexico and portions of the Texas Panhandle. In this region, stronger surface flow will coincide with 12-15% RH for a few hours Friday afternoon. South of this region, critical RH will exist amidst somewhat weaker surface winds. Farther north, RH values should remain somewhat higher despite stronger (25-35 mph) surface flow. Also expanded the elevated area farther east into southwestern Kansas and western Oklahoma, where near-critical conditions will likely exist for a few hours along and west of a sharpening dryline. See the previous discussion below for more information. ..Cook.. 11/16/2017 .PREV DISCUSSION... /ISSUED 0140 AM CST Thu Nov 16 2017/ ...Synopsis... The western trough will shift east and deepen over the Plains by Saturday morning. Stronger height falls will result in intensifying lee low over eastern CO. The combination of stronger deep layer westerlies and a tighter surface pressure gradient, in conjunction with warmer temperatures and lower RH conditions, will lead to more widespread fire weather concerns across the southern High Plains Friday afternoon. ...Southern High Plains... Temperatures will be warmer on Friday with highs in the 70s and 80s. Forecast soundings also show a more deeply mixed boundary layer than on Thursday. This will allow for downward transport of stronger midlevel westerlies and, in conjunction with downslope aided drying, elevated to locally critical fire weather conditions will be possible. West to southwest surface wind speeds of 15-25 mph with higher gusts are possible. The strongest winds are expected across NM into southeast CO. RH values will range from 15-20 percent across much of NM into the OK/TX Panhandles with slightly higher values across southeast CO and southwest KS. Some locally critical conditions are possible across parts of northeast NM in the vicinity of I-40. Questionable fuel conditions and spotty nature of critical potential will preclude an upgrade at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 2 Fire Weather Outlook

Weather - Fire Weather - Thu, 11/16/2017 - 12:53
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1252 PM CST Thu Nov 16 2017 Valid 171200Z - 181200Z ...CRITICAL FIRE WEATHER AREA FOR EAST-CENTRAL NEW MEXICO EASTWARD INTO PORTIONS OF THE TEXAS PANHANDLE... After coordination with affected local WFOs, decided on an upgrade to critical for a small part of east-central New Mexico and portions of the Texas Panhandle. In this region, stronger surface flow will coincide with 12-15% RH for a few hours Friday afternoon. South of this region, critical RH will exist amidst somewhat weaker surface winds. Farther north, RH values should remain somewhat higher despite stronger (25-35 mph) surface flow. Also expanded the elevated area farther east into southwestern Kansas and western Oklahoma, where near-critical conditions will likely exist for a few hours along and west of a sharpening dryline. See the previous discussion below for more information. ..Cook.. 11/16/2017 .PREV DISCUSSION... /ISSUED 0140 AM CST Thu Nov 16 2017/ ...Synopsis... The western trough will shift east and deepen over the Plains by Saturday morning. Stronger height falls will result in intensifying lee low over eastern CO. The combination of stronger deep layer westerlies and a tighter surface pressure gradient, in conjunction with warmer temperatures and lower RH conditions, will lead to more widespread fire weather concerns across the southern High Plains Friday afternoon. ...Southern High Plains... Temperatures will be warmer on Friday with highs in the 70s and 80s. Forecast soundings also show a more deeply mixed boundary layer than on Thursday. This will allow for downward transport of stronger midlevel westerlies and, in conjunction with downslope aided drying, elevated to locally critical fire weather conditions will be possible. West to southwest surface wind speeds of 15-25 mph with higher gusts are possible. The strongest winds are expected across NM into southeast CO. RH values will range from 15-20 percent across much of NM into the OK/TX Panhandles with slightly higher values across southeast CO and southwest KS. Some locally critical conditions are possible across parts of northeast NM in the vicinity of I-40. Questionable fuel conditions and spotty nature of critical potential will preclude an upgrade at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Thu, 11/16/2017 - 11:56

000
AXNT20 KNHC 161756
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1256 PM EST Thu Nov 16 2017

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
1545 UTC.

...SPECIAL FEATURES...
A 1000 mb low is centered 33N51W with the associated cold front
extending SW from the low to 27N63W. The low is supported aloft by
an upper level trough with axis extending from 38N53W to 31N57W.
Near gale to gale force S-SW winds are expected for the next 18
hours generally N of 28N between the front and 48W. An early
morning scatterometer pass indicated this wind field which extends
north of the area to 34N/35N. See the latest NWS High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details.

...ITCZ/MONSOON TROUGH...
The monsoon trough extends from the African coast near 07N12W to
08N28W. The Intertropical Convergence Zone axis extends from
08N28W to 08N38W to 06N50W to 07N58W. Scattered moderate
convection is from 01N-08N between the Prime Meridian and 17W.
Widely scattered moderate convection is from 04N-12N between 17W-
46W.

...DISCUSSION...

GULF OF MEXICO...
NW flow aloft prevails over the Gulf basin this afternoon as a
mid-level shortwave trough progresses eastward over the far
eastern Gulf and Florida peninsula. Mostly stable conditions are
noted at the surface as a ridge axis extends from across the SE
CONUS to the SW Gulf and east-central Mexico near 22N97W. Skies
are mostly clear with the exception of a few possible isolated
showers within 90 nm either side of a surface trough analyzed
from 19N92W to 23N97W. Otherwise...gentle to moderate
anticyclonic winds are forecast through Friday. The next cold
front is expected to emerge off the Texas and Louisiana coasts by
late Saturday into Saturday night. Fresh to strong N-NE winds will
follow in wake of the front as it sweeps southeastward.

CARIBBEAN SEA...
A broad area of lower pressure across the basin continues to be
focused on a 1008 mb low centered SW of Hispaniola near 17N75W. A
surface trough extends SW from the low to near 10N81W supporting
scattered showers and strong tstms from 09N-16N between 70W-
83W...and from 16N-21N between 59W-74W. Otherwise...moderate to
occasional fresh northerly winds are noted across the western
Caribbean waters generally W of 77W...while trade wind flow E of
the surface troughing will continue to be disrupted outside of
convection...gentle to moderate southerly winds will prevail
through the upcoming weekend. The low is expected to remain nearly
stationary S-SW of Hispaniola early Monday.

...HISPANIOLA...
Scattered showers and scattered strong tstms are expected to
persist across the island the next few days as deep moisture
advects NE over the region due to an upper trough to the NW over
the SE Gulf of Mexico. Convection will likely be heaviest in the
afternoon and evening hours during maximum heating. Localized
flooding and life-threatening mud slides are also possible during
this time.

ATLANTIC OCEAN...
Aside from the special features section above highlighting the
area of low pressure analyzed near 33N51W...the SW North Atlc is
under the influence of moderate to occasional fresh N-NE winds
with a dissipating cold front extending into the discussion area
near 32N75W to the Florida coast near 27N80W. Isolated showers are
occurring across the NW Bahamas and Florida Straits...and along
the Florida east coast S of 29N. Farther east...a surface trough
extends SW from the Special Features cold front near 31N54W to
23N70W and into the 1008 mb low centered in the Caribbean Sea near
17N75W. Scattered showers and widely scattered tstms are occurring
from 18N-26N between 58W-73W...and from 26N-32N between 40W-58W.
The frontal troughing is expected to persist across the central
Atlc through Saturday night as ridging builds in off the SE CONUS
and into the SW North Atlc. Finally...mostly tranquil conditions
are noted across the eastern Atlc...however a surface trough
extends from a 1012 mb low centered in the vicinity of the Azores
near 37N24W and is supporting widely scattered showers N of 27N
between 18W-23W.

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

$$
HUFFMAN

Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Thu, 11/16/2017 - 09:53
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Thu Nov 16 2017 Valid 161700Z - 171200Z Ongoing forecast is on track, with elevated fire weather conditions remaining likely in east-central New Mexico and vicinity. See the previous discussion below for more details. ..Cook.. 11/16/2017 .PREV DISCUSSION... /ISSUED 0140 AM CST Thu Nov 16 2017/ ...Synopsis... Progressive upper level flow will bring a trough east across the Pacific Northwest and northern Rockies today. As a result, enhanced deep layer flow will overspread much of the western U.S. and Rockies. Height falls will induce surface lee low development across the northern High Plains with a trough extending south through the southern High Plains. Some locally elevated fire weather conditions will be possible across parts of northeast NM where breezy downslope winds and low RH conditions are possible. ...Portions of northeast New Mexico... Downslope westerly winds will aid in warming and drying in the vicinity of the central mountains and adjacent plains across northeast NM. Boundary layer mixing is unimpressive in forecast sounding data with many locations even showing an inversion aloft. This will limit strongest midlevel wind speeds from mixing to the surface. However, west/southwest surface winds will still be sufficient, when combined with low RH values to result in some areas of elevated fire weather potential. Wind speeds around 15mph with some higher gusts are expected as RH values fall into the 15-20 percent range. Stronger wind speeds will be possible along the higher terrain of the central mountains, but RH values may be a bit higher. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

SPC Day 1 Fire Weather Outlook

Weather - Fire Weather - Thu, 11/16/2017 - 09:53
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0951 AM CST Thu Nov 16 2017 Valid 161700Z - 171200Z Ongoing forecast is on track, with elevated fire weather conditions remaining likely in east-central New Mexico and vicinity. See the previous discussion below for more details. ..Cook.. 11/16/2017 .PREV DISCUSSION... /ISSUED 0140 AM CST Thu Nov 16 2017/ ...Synopsis... Progressive upper level flow will bring a trough east across the Pacific Northwest and northern Rockies today. As a result, enhanced deep layer flow will overspread much of the western U.S. and Rockies. Height falls will induce surface lee low development across the northern High Plains with a trough extending south through the southern High Plains. Some locally elevated fire weather conditions will be possible across parts of northeast NM where breezy downslope winds and low RH conditions are possible. ...Portions of northeast New Mexico... Downslope westerly winds will aid in warming and drying in the vicinity of the central mountains and adjacent plains across northeast NM. Boundary layer mixing is unimpressive in forecast sounding data with many locations even showing an inversion aloft. This will limit strongest midlevel wind speeds from mixing to the surface. However, west/southwest surface winds will still be sufficient, when combined with low RH values to result in some areas of elevated fire weather potential. Wind speeds around 15mph with some higher gusts are expected as RH values fall into the 15-20 percent range. Stronger wind speeds will be possible along the higher terrain of the central mountains, but RH values may be a bit higher. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
Categories: Weather

NHC Atlantic Tropical Weather Discussion

NWS Weather - Thu, 11/16/2017 - 05:51

000
AXNT20 KNHC 161151
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
651 AM EST Thu Nov 16 2017

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
1115 UTC.

...SPECIAL FEATURE...

...GALE-FORCE WINDS IN THE CENTRAL ATLANTIC OCEAN...
A 1002 mb low pressure center is near 32N54W. A cold front
extends from the low center to 30N63W and 26N66W. The cold front
is dissipating from 26N66W to 25N75W. A surface trough is along
31N56W 27N60W 25N66W 21N73W. Gale-force S to SW winds and sea
heights ranging from 9 feet to 14 feet, N of 28.5N E of the
surface trough to 50W, during the next 24 hours. Upper level
anticyclonic wind flow is on top of the area of the cold front and
surface trough. Precipitation: isolated to widely scattered
moderate and locally strong within 300 nm on either side of the
line from the eastern part of the Dominican Republic near 19N68W,
to 26N55W, beyond 32N50W. Please read the latest NWS High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details.

...ITCZ/MONSOON TROUGH...
The monsoon trough passes through Sierra Leone near 08N13W to
08N18W. The ITCZ continues from 08N18W to 08N23W to 06N33W, to
the coastal waters of French Guiana near 05N52W. Precipitation:
widely scattered moderate to isolated strong from 02N to 11N from
37W eastward.

An upper level trough extends from a 32N22W cyclonic circulation
center to 24N24W 16N36W 09N45W and 04N50W. Precipitation:
Isolated moderate rainshowers from 04N to 17N between 37W and
60W.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level NW wind flow, dry air, and subsidence span the entire
area.

A surface trough is along 22N94W 19N91W, in the SW corner of the
Gulf of Mexico. Rainshowers are possible from 20N to 23N between
87W and 94W.

A surface ridge extends from a southern Alabama 1021 mb high
pressure center, into the west central Gulf of Mexico, to 18N96W
in southern Mexico.

...THE CARIBBEAN SEA...

A surface trough extends from a 1007 mb low pressure center that
is near 18N76W, off the eastern coast of Jamaica, to 11N81W. The
monsoon trough continues from 11N81W, across Costa Rica, into the
eastern Pacific Ocean. Precipitation: scattered moderate to strong
rainshowers within 90 nm on either side of the line from 18N72W
14N74W 10N82W.

An upper level ridge extends from NW coastal Venezuela beyond the
NE corner of the Caribbean Sea. Broad upper level anticyclonic
wind flow spans nearly the entire Caribbean Sea. An upper level
trough is moving through the NW corner of the Caribbean Sea.

...HISPANIOLA...

Numerous rainshowers will persist across Hispaniola during the
next few days. Deep moisture is going to be pulled NE across the
area due to an upper level trough that is to the west of the
island. The precipitation amounts will be comparatively the
greatest in the afternoon and evening hours during maximum
heating. Localized flooding and life-threatening mud slides are
also possible during this time.

The GFS model for 250 mb shows that SW wind flow will move across
the area during the next 48 hours. The GFS model for 500 mb shows
that SW wind flow will move across the area during the next 48
hours. Hispaniola will be on the eastern side of a trough. The
GFS model for 700 mb shows that SW wind flow will move across the
area during day one. The trough that is just to the west of
Hispaniola during day one will move across Hispaniola during day
two.

...THE ATLANTIC OCEAN...

A middle level to upper level trough passes through 32N60W to
26N74W, across Cuba, into the NW corner of the Caribbean Sea to
the Gulf of Honduras. The trough is surrounded by comparatively
drier air in subsidence.

A cold front passes through 32N77W to 31N79W. The cold front is
dissipating from 31N79W to 28N80W and 25N80W. A surface trough
curves from 32N76W to 30N75W to 28N77W. Precipitation: isolated
moderate rainshowers are to the NW of the line that passes through
32N70W 28N70W 25N74W 23N80W, in the Atlantic Ocean and in the
Florida Straits.

A surface trough passes through 32N21W to 31N21W. Precipitation:
widely scattered moderate to isolated strong from 28N northward
between 20W and 23W.

A surface ridge extends from a 1018 mb high pressure center that is
near 33N37W, to 24N42W, to 17N50W.

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

$$
MT
Categories: Weather

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