[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291816
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Tue Sep 29 2020

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
1750 UTC.

...SPECIAL FEATURES...

...GULF OF MEXICO GALE WARNING...

A strong cold front has entered the Gulf waters and now extends
from 29N84W to 20N96W. Scattered moderate to strong convection
is from 18N-23N and west of 90W. The front will reach the SE Gulf
waters Wed and the Straits of Florida by Wed evening. In the wake
of the front, strong northerly winds are forecast in the western
half of the basin, with gale force winds expected west of 95W.
Seas are forecast to build to 18 ft over the SW Gulf by this
afternoon/evening. These conditions will dissipate by Wed
morning. Please see the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...TROPICAL WAVES...

A tropical wave over the eastern Atlantic is along 18W from
01N-14N. The wave is moving west at about 10-15 kt. Scattered
showers are noted in the vicinity of this wave.

A tropical wave axis is along 44W from 01N-15N, moving W at
10-15 kt. Scattered moderate convection is from 05N-14N between
40W-46W.

A tropical wave axis is along 61W from 10N-19N, moving W at
10-15 kt. Scattered moderate convection is from 13N-20N between
58W-63W.

A tropical wave moving across the central Caribbean is currently
located along 73W, moving W at 10 kt. Scattered showers are noted
south of Hispaniola, and adjacent waters. This wave will
continue moving westward across the basin through the period
accompanied by active weather and enhanced winds along with
building seas. This feature is expected to become part of a broad
low-pressure area over the western Caribbean in a few days.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa near 10N14W
to 05N30W. The ITCZ extends from 05N30W to 06N39W. The ITCZ
resumes W of a tropical wave near 05N46W to 03N54W. Besides the
convection mentioned in the tropical wave section, no significant
convection is noted near these boundaries at this time.

Gulf of Mexico...

Refer to the section above for details on the Gale Warning
currently in effect for the SW Gulf.

A surface ridge from the Atlantic extends across Florida into the
eastern Gulf. Surface trough is noted south of the cold front in
the Bay of Campeche. Drier air is moving into the far northwest
Gulf of Mexico behind the cold front. The most recent scatterometer
Data depict light to gentle winds over the southeast Gulf, and
gentle to moderate southerly winds ahead of the front. Fresh to
strong northerly winds follow the front.

Looking ahead, the cold front will continue moving SE across the
basin with strong to near gale force northerly winds behind it
and gale force winds in the region of Veracruz through tonight.
A secondary frontal boundary will drop southward to the northern
Gulf early on Fri and reach the far southwestern Gulf by Fri
evening. Strong high pressure will build in behind this front.
The pressure gradient between the front and broad low pressure
that is expected to form over the western Caribbean by the end of
the week is expected to freshen the northeast winds over most of
the southeastern Gulf by the end of the week. These winds may
reach strong speeds on Sat along with building seas.

CARIBBEAN SEA...

A tropical wave is moving over the central Caribbean, while
another one is approaching the Lesser Antilles. Please refer to
the Tropical Waves section above for details.

Scattered moderate convection is noted between the two tropical
waves in the eastern Caribbean between 65W-70W. West of the
tropical waves, a 1006 mb low pressure is noted over northern
Colombia with the Pacific monsoon trough extending west across
Panama and Costa Rica. Scattered moderate convection is noted
along the boundary south of 13N between 76W-83W. To the NW,
limited convection is noted. Scatterometer data depicts light to
moderate trade winds across most of the basin except between 60W-
70W, where moderate to fresh winds prevail.

Moderate to fresh trade winds over the central Caribbean will
increase to fresh to strong speeds tonight. Moderate winds will
continue elsewhere, except for gentle winds over the northwestern
Caribbean. A tropical wave, currently located near 73W, will
continue moving westward across the basin through the period
accompanied by active weather and enhanced winds along with
building seas. This feature is expected to become part of a broad
low pressure area over the western Caribbean over the next few
days.

ATLANTIC OCEAN...

Refer to the section above for details on the tropical waves
moving across the tropical Atlantic.

Surface ridging prevails across the basin, anchored by a 1031 mb
high is centered over the central Atlantic near 39N45W.

Weak high pressure over the western Atlantic is maintaining
gentle to moderate winds across the area. The high pressure will
begin to retreat eastward through Wed in response to a cold front
that will reach the southeastern U.S. coast tonight and move over
the northwest part of the area through Wed. The front will weaken
through the end of the week. Scattered showers and thunderstorms
are expected ahead of the cold front.

Torres
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