[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 241633
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1133 AM EST Sun Dec 24 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
1715 UTC.

...Gale Warning for the coast of Colombia...

High pressure over the Atlantic will continue to tighten the
pressure gradient over the south-central and southwest Caribbean
Sea, supporting minimal gale-force winds off the coast of
Colombia at night through tonight. The high pressure will weaken
Monday, but will maintain strong trades over the Central and SW
Caribbean through Thursday, with near gale force nocturnal winds
near the coast of Colombia. Please read the latest NHC High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more
details.

...ITCZ/MONSOON TROUGH...

The monsoon trough enters the Atlantic Ocean through Nigeria and
and continues to 03N at the Prime Meridian to 03N12W. The ITCZ
axis extends from 03N12W to 05N20W to 03N30W to 03N40W to NE
Brazil near 02N51W. Scattered moderate isolated strong convection
is within about 150 nm N of the ITCZ axis between 27W and 43W.
Scattered moderate convection is from 05N-08N between 43W-50W.
Similar convection is also along the Equator at 47W.


...DISCUSSION...

GULF OF MEXICO...

As of 1500 UTC, a cold front extends from the Florida Big Bend to
near 26N90W where it becomes stationary to the central Bay of
Campeche near 18N94W. Currently, gentle to moderate northerly
winds are noted behind the front while light and variable winds
are ahead of the front N of 27N. Seas are generally in the 4-6 ft
range. E of the front, a ridge from the Atlantic Ocean, extends
across Florida into the eastern Gulf of Mexico, with a 1023 mb
high pressure located over south Florida. This system is bringing
mostly clear skies, light winds, and warm temperatures across
South Florida. The northern half of the front will drift east this
afternoon, ahead of a reinforcing cold front moving across the
northern Gulf waters. The fronts will merge this evening and reach
from SW Florida to near Veracruz, Mexico Mon morning, before
stalling and weakening from the Straits of Florida to near
Veracruz late Mon. Fresh to strong N-NE winds will follow the
reinforcing cold front with seas building to 6-7 ft across the
northern and SW Gulf.

CARIBBEAN SEA...

Latest scatterometer data continue to show fresh to strong winds
across the central Caribbean, while moderate to fresh NE winds
are noted in the lee of eastern Cuba, and just west of Jamaica.
Seas of 10-11 ft are in this region with the strongest winds near
the coast of Colombia. Please, see Special Features section for
more details. Patches of low level moisture embedded in the trade
wind flow are producing isolated to scattered passing showers
over the Greater and Lesser Antilles from time to time. Showers
carried by the trades are aslo affecting parts of Central America.
Fresh to strong NE winds are expected through the Windward
Passage on Tue and Wed. Large E swell will build seas to 9 ft E
of the Lesser Antilles along 55W beginning on Mon night, with
these swells reaching the E Atlantic passages on Tue evening and
continuing through Thu evening.

...HISPANIOLA...

Low-topped trade wind showers will continue to move across the
island from time to time. Mostly dry and stable conditions are
expected to persist over the next couple of days under the
influence of a mid-upper level ridge and associated strong
subsidence.

ATLANTIC OCEAN...

A ridge extends across the Atlantic waters, including the Bahamas
and the State of Florida, with a 1023 mb high pressure situated
over south Florida. A weak trough extends from 31N59W to 28N60W.
The ridge will retreat eastward as a cold front moves off the NE
Florida coast tonight accompanied by fresh to locally strong
veering winds from SW to NW across the waters N of 30N. the front
will reach from 31N73W to south Florida by early Monday afternoon,
then stall from 31N63W to the Northern Bahamas on Tue while gradually
weakening. The remainder of the Atlantic will continue under the
influence of a ridge, anchored by a high pressure located near
the Azores. This system will undergo occasional intensity fluctuations,
resulting in a rather tight pressure gradient across the waters N
of the ITCZ/Monsoon Trough between the coas of Africa and the
Lesser Antilles through at least Wednesday. In addition, this
high pressure has displaced the monsoon trough/ITCZ farther south.

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

$$
GR
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