[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242351
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
651 PM EST Sun Nov 24 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 1800 UTC surface analysis and satellite imagery through
2320 UTC.

...SPECIAL FEATURES...

Tropical Storm Sebastien is near 39.2N 32.5W at 24/2100 UTC,
moving ENE at 34 kt. It is located about 300 miles WNW of the
Azores. Estimated minimum central pressure is 994 mb with maximum
sustained wind speeds of 55 kt and gusts to 65 kt. Scattered
moderate convection is seen within 60 nm of the center in the
southern semicircle and 300 nm northern semicircle. An even faster
motion toward the northeast or east- northeast is expected during
the next day or so. On the forecast track, the center of
Sebastien will pass near the western Azores tonight. A slow
decrease in the maximum winds is expected during the next day or
so. Sebastien is forecast to become post-tropical by early Monday,
and it could degenerate into a trough of low pressure at any time
during the next couple of days. Regardless of status, Sebastien
or its remnants will likely continue to produce tropical-storm-
force winds for at least a couple more days. The Public Advisories
for Sebastien are available via AWIPS/WMO headers
MIATCPAT5/WTNT35 KNHC. The Forecast/Advisories for Sebastien are
available via the AWIPS/WMO headers MIATCMAT5/WTNT25 KNHC and at
www.hurricanes.gov

Western Atlantic Gale

A cold front continues to move eastward across the western
Atlantic, extending from 31N73W to SE Florida near 27N80W at
24/2100 UTC. Minimal SW gale force wind are ongoing N of 30N E of
the front to 73W. Seas are expected to be 8 to 10 ft. These gale
force winds will end by 0000 UTC. See the latest NWS High Seas
Forecast issued by the National Hurricane Center under AWIPS/WMO
headers HSFAT2/FZNT02 KNHC or at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave has an axis along 48W from 13N
southward and is moving W at 15 kt. The tropical wave shows up
well in TPW imagery and model diagnostics. Scattered moderate with
isolated strong convection is seen from 05N-11N between 46W-51W.

A Caribbean Sea tropical wave has an axis along 65W from 13N
southward and is moving W at 10-15 kt. No significant convection
is currently associated with this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of Sierra
Leone near 08N13W to 06N17W. The ITCZ continues from 06N17W to
05N30W to 05N46W. Aside from the convection related to the
tropical waves, scattered to numerous moderate with isolated
strong convection is within 200 nm either side of the ITCZ
between 18W-46W.

GULF OF MEXICO...

A cold front extends from SW Florida near 26N82W southwestward to
the central Gulf near 24N87W to a 1015 mb low near 22N95W. A
stationary front extends south of this low toward Mexico near
19N95W. A line of showers extend along the front and the low. High
pressure continues to build behind the front anchored by a 1020
mb high near 31N93W. Latest scatterometer data depicts moderate to
fresh NW winds behind the front. Light winds are seen in the NW
Gulf near the high.

The cold front will reach from the Straits of Florida to the
northern Yucatan Peninsula adjacent waters tonight where it will
stall and weaken through Monday morning. High pressure will build
in the wake of the front from W to E, shifting NE of the basin by
early Tuesday. The next cold front is expected to move into the
NW Gulf by early Wednesday, weakening and stalling in the
northern Gulf by Wednesday night. SE return flow around high
pressure over the Carolinas will prevail Thursday and Thursday
night.

CARIBBEAN SEA...

An upper-level trough axis extends from the Windward Passage to
the Costa Rica/Nicaragua border. A surface trough is seen near the
same area, extending from 13N79W to 19N76W. Isolated showers and
thunderstorms are near the upper-level trough axis. In the
eastern Caribbean near the Windward Islands, scattered moderate
convection is seen from 10N- 15N between 56W-63W. The remainder
of the Caribbean is relatively quiet. The latest scatterometer
pass shows fresh winds across portions of the central Caribbean
between 71W- 75W with moderate winds elsewhere in the eastern and
central Caribbean. Gentle winds are in the NW basin.

Gentle to moderate trades will prevail across the area through
tonight with mainly northerly winds across the NW Caribbean. Winds
will begin to increase across the south- central Caribbean late
on Monday. Expect fresh to strong winds across the central part
of the basin Monday night through Thursday, with these winds
spreading westward toward the coast of Nicaragua Tuesday night
into Wednesday. At that time, strong to near gale force winds are
forecast near the coast of Colombia.


ATLANTIC OCEAN...

See the Special Features section for more information on the gale
warning in the western Atlantic.

Showers are seen within 100 nm of the front N of 25N. A cold front
is beginning to form in the wake of T.S. Sebastien in the central
Atlantic, extending from 28N43W to 38N34W. A 1013 mb low is south
of this forming front near 22N50W with a trough extending along
the low from 18N54W to 27N43W. Showers are seen along both of
these features from 18N-31N between 37W-54W. Meanwhile, an upper
level low near 24N26W has a surface trough associated with it,
analyzed from 24N27W to 30N24W. Showers with isolated
thunderstorms are seen from 22N-31N between 13W-25W, including the
Cabo Verde Islands. Surface high pressure dominates the rest of
the basin anchored by a 1019 mb high near 30N54W and a 1021 mb
high near 32N16W. Latest scatterometer data and surface
observations depict moderate NW winds behind the cold front.

The cold front will reach from 31N69W to the Straits of Florida
tonight and from 31N65W to the central Bahamas and western Cuba
on Monday. High pressure will build in the wake of the front.
Another cold front is forecast to move across the forecast waters
Thursday and Thursday night with fresh to strong winds mainly
affecting the NE waters.

$$
AKR
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