[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 282314
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Mon Sep 28 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 0000 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

...GULF OF MEXICO GALE WARNING...

A strong cold front has entered the Gulf waters and now extends
from southwestern Louisiana to inland Texas near Brownsville. A
large area of scattered showers and thunderstorms are noted
ahead of the frontal boundary, covering mainly the waters from
23N-28N W of 85W. 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 on Tue.
Seas are forecast to build to 18 or 19 ft over the SW Gulf by Tue
afternoon and evening. A secondary front 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 SE Gulf by the end of the week. These winds may
reach strong speeds on Sat and Sat night along with building
seas. Please see the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...TROPICAL WAVES...

A tropical wave is approaching the west coast of Africa, and will
likely be added to the 0000 UTC surface map. The Hovmoller
Diagram indicates the westward propagation of the wave, and
satellite imagery shows a cluster of moderate convection from
10N-13N between 12W-16W.

A tropical wave axis is along 37W from 03N-18N, moving W at
10-15 kt. Scattered moderate convection is from 08N-11N between
35W-41W.

A tropical wave axis is along 57W from 03N-18N, moving W at
10-15 kt. Scattered moderate convection is from 10N-16N between
50W-60W.

A tropical wave moving across the eastern Caribbean is currently
located along 70W, moving W at 10 kt. Scattered to numerous
moderate convection is noted behind the wave from 11N-18N between
the Lesser Antilles and the wave axis. The wave is helping to
induce convection over Puerto Rico and regional waters as well as
over Dominican Republic. 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 12N16W
to 09N30W. The ITCZ extends from 08N41W to 11N50W. Besides the
convection mentioned in the tropical wave section, scattered
moderate convection is noted from 08N-10N between 41W-46W.

Gulf of Mexico...

A strong cold front is moving across the Gulf of Mexico. This
front is forecast to produce gale-force winds. Refer to the
Special Features section for more details. A ridge from the
Atlantic extends across Florida into the eastern Gulf. The most
recent scatterometer data depict light to gentle winds over the
eastern Gulf, and gentle to moderate southerly winds ahead of the
front. Fresh to strong northerly winds follow the front.

CARIBBEAN SEA...

A tropical wave is moving over the E Caribbean. Please refer to
the Tropical Waves section above for details.

Moderate to fresh trade winds over the central Caribbean will
increase to fresh to strong speeds by mid-week. Moderate winds
will continue elsewhere, except for gentle winds over the
northwestern Caribbean.

Looking ahead, a broad area of low pressure is expected to form
over the western Caribbean Sea in a few days. Environmental
conditions are expected to be conducive for some gradual
development thereafter, and a tropical depression could form late
this week or this weekend while the system moves slowly west-
northwestward over the northwestern Caribbean Sea. The latest
Tropical Weather Outlook states that this system has a medium
chance of tropical cyclone formation through 5 days. Refer to
the latest Tropical Weather Outlook at www.hurricanes.gov for
more details.

ATLANTIC OCEAN...

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

Convection continues to flare-up over Florida due to abundant
moisture and a diffluent pattern aloft. The cold front now over
the Gulf of Mexico is forecast to reach South Florida on Wed.

High pressure of 1031 mb located W of the Azores dominates the
area. This system is maintaining generally gentle to moderate
winds across the area. The high pressure will begin retreat
eastward through Wed in response to a cold front that will be
moving across the southeastern U.S. This cold front will reach
the southeastern U.S. coast Tue night and move over the northwest
part of the area through Wed. The front will begin to weaken as
it reaches from near 31N74W to South Florida by Wed night and
become stationary from 31N73W to the Straits of Florida by late
Thu through Fri night, then diffuse Sat. Scattered showers and
thunderstorms are expected ahead of the cold front.

$$
GR
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