Tropical Weather Discussion
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000
AXNT20 KNHC 051802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
102 PM EST Tue Dec 5 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
1745 UTC.

...SPECIAL FEATURES...

...GALE-FORCE WINDS IN THE GULF OF MEXICO...

A cold front currently extending from the upper great lakes SW to
the lower Mississippi Valley to the southern plains will enter the
NW Gulf waters later this afternoon. Strong high pressure
building behind the front will tighten the pressure gradient in
that region of the basin, thus supporting frequent gust to gale
force winds starting 1200 UTC Wednesday. Winds will then increase
to gale force over the west-central Gulf on Thu, and over the SW
Gulf by Thu night. Please read the latest NWS High Seas Forecast
under AWIPS/WMO headers MIAHSFAT2/FZNT02 for more details.

...GALE-FORCE WINDS IN THE ATLANTIC...

A system of low pressure is N of the forecast waters with
associated cold front extending from 30N49W SW to 27N56W to
27N64W. Scatterometer data continue to show gale force winds N of
30N W of the front to 58W. The front will continue to drift ESE
during the next 24 hours when the winds are expected to decrease
below gale force. Please read the latest NWS High Seas Forecast
under AWIPS/WMO headers MIAHSFAT2/FZNT02 for more details.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the African coast near 08N13W to
07N17W. The Intertropical Convergence Zone axis extends from
07N17W to 04N38W to 06N58W. Scattered moderate convection is
within 120 nm S of the ITCZ W of 20W.

...DISCUSSION...

GULF OF MEXICO...

Return moderate flow dominates the Gulf waters ahead of the next
cold front entering the NW basin later this afternoon. Except for
isolated showers off the SE coast of Texas observed in radar
imagery, the basin is devoid of convection due to deep layer dry
air. Strong high pressure building behind the front will tighten
the pressure gradient in the NW Gulf and will support frequent
gust to gale force winds starting 1200 UTC Wednesday. Scattered
showers will be associated with this front as it moves across the
basin. Heavy showers are expected in the SE Gulf Friday into
Saturday as the front moves off the basin. For further details
see special features.

CARIBBEAN SEA...

Deep moisture over the SW Caribbean is interacting with diffluent
flow aloft to support a cluster of moderate to isolated strong
convection S of 13N W of 78W. East of this area of convection a
1009 mb embedded in the eastern extension of the EPAC monsoon
trough support scattered showers S of 12N between 75W and 78W. A
surface trough is over the E Caribbean with axis extending from
19N61W to 11N62W and supports showers and thunderstorms over
Puerto Rico, the Virgin Islands and the Lesser Antilles.The
remainder of the Caribbean is generally void of convection. High
pressure north of the region supports fresh to strong trades over
the Central Caribbean between 64W and 82W, and moderate trades
elsewhere. Little change is expected over the next 48 hours.

...HISPANIOLA...

Deep layer dry air in the region supports fair weather today. No
major changes are expected until the weekend when a moist airmass
will enter the eastern half of the Island supporting scattered
showers.

ATLANTIC OCEAN...

Strong high pressure anchored over the NW Atlc waters extends a
ridge axis SSW covering the SW N Atlc waters generally W of 62W.
In the central Atlc, a middle to upper level low with associated
trough continue to support a cold front extending from 30N49W SW
to 27N56W to 27N64W. Gale force winds are W of this front N of
30N. See special features section for further details. A middle
level low near 47N32W supports another frontal system analyzed as
a stationary front along 30N32W SW to 23N50W to 21N63W. Scattered
showers and isolated tstms are within 120 nm either side of the
boundary. This front is forecast to dissipate within the next 24
hours. High pressure centered over Spain extends SW and covers the
remainder of the eastern Atlantic.

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

$$
Ramos



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