[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181140
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
640 AM EST Wed Dec 18 2019

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...

A cold front moving across the SE Gulf of Mexico will continue
to enhance strong to Gale force winds over portion of the western
Gulf today. ASCAT data indicates Gale force winds over portion of
the western Gulf from 18N-20N and west of 95W. This strong gale
force winds will continue through the afternoon in the southwestern
Gulf of Mexico, mainly south of 22N and west of 93W. Elsewhere
behind the front, winds of 25-30 kt will continue through tonight,
with frequent gusts to gale force south of 26N and west of 87W.
Seas of 11-17 ft will occur over portions of the southwestern Gulf
of Mexico through Wednesday morning. See the latest NWS High Seas
Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for
further details.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Sierra Leone near
08N12W to 03N18W, then ITCZ continues at that point west to 02N35W
to 01N46W. Scattered moderate convection is seen within 90 nm on
either side of the boundary between 20W-40W. Scattered showers
are seen near the coast of Sierra Leone.

GULF OF MEXICO...

See the section above for details on the Gale Warning in the
Gulf of Mexico.

ASCAT data shows fresh to strong northerly winds behind the front
across central and western portion of the Gulf of Mexico with the
exception of gale force winds also seen north of 19N and west of
94W. A pre-frontal trough extends 100 nm southeast ahead of the
front. Scattered moderate isolated strong convection is seen over
the SE Gulf north of 21N between 81W-87W. Convection is being
enhanced by upper level diffluence. Elsewhere, drier and cool air
is making its way into the basin behind the front.

A strong cold front extending from north-central Florida to the
Yucatan peninsula will move southeast of the area later today.
Northerly gale force winds and large seas behind the front in the
SW Gulf will persist through early evening. Winds and seas will
diminish over the central and western Gulf Thu and Thu night.
Strong NE to E winds will continue over the Straits of Florida
after the frontal passage Thu through Fri night. A low pressure
area is expected to develop over the eastern Gulf Fri night and
move across northern Florida this weekend.

A heavy rainfall event is expected now through Wed for the Mexican
states of Chiapas, Tabasco southern portions of Campeche. Currently,
rains have already begun over much of the Yucatan Peninsula. In
Mexico, the maximum rainfall amounts may range from 4 to 6 inches.
The most intense rainfall is expected on Wed through Thu morning,
These rains will likely cause localized flooding and possible
mudslides.

CARIBBEAN SEA...

A surface trough over the Yucatan Peninsula is inducing scattered
moderate with isolated strong convection over the Yucatan Channel
as well as the east coast of the Yucatan Peninsula, the Gulf of
Honduras and Belize. Elsewhere in the NW Caribbean, scattered
showers extend to beyond the Cayman Islands, mainly north of 16N
between 79W-85W. In the far SW Caribbean, the east Pacific monsoon
trough is inducing scattered moderate with isolated strong convection
south of 11N between 73W-84W, including over Colombia, Panama and
Costa Rica. Scattered light to moderate showers are seen over
Puerto Rico and Hispaniola. The ASCAT pass shows fresh to locally
strong winds across the eastern and central Caribbean, east of
81W, and light to moderate winds across the SW and NW portion.

High pressure north of the region will maintain fresh to strong
trade winds and building seas from the tropical north Atlantic
westward to the south central Caribbean through Sat. A strong
cold front will move into the Yucatan Channel this afternoon,
then stall and weaken from central Cuba to Honduras by Thu night.
Fresh to strong northerly winds will accompany the front in the
NW Caribbean. Heavy rain is also expected to affect northern and
central Guatemala, much of Belize, and northwestern Honduras
today through Thu.

ATLANTIC OCEAN...

A cold front has entered the western Atlantic waters extending
from a 1007 mb low pressure near 34N77W. A pre-frontal trough
about 90 nm ahead of the front extends from 30N78W to 27N80W.
Line of tstorms ahead of the trough extends over the western
Atlantic from 25N between 74W-80W. Further east, a 1025 mb
high pressure is centered near 30N49W maintaining fair weather
across the basin. Moderate to fresh easterly winds are depicted
by the latest ASCAT pass.

A strong cold front from 31N80W to northern Florida will reach
from 31N70W to western Cuba tonight, and from 27N65W across the
Bahamas to central Cuba on Thu night. Strong northerly winds and
building seas are expected across much of the forecast waters
following frontal passage. The front will gradually stall and
weaken stall through Fri night. Fresh to strong easterly winds may
develop east of Florida this weekend as a low pressure area in
the Gulf of Mexico moves across northern Florida.

$$
NATIONAL HURRICANE CENTER
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