[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291752
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Oct 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
1640 UTC.

...SPECIAL FEATURES...

Tropical Storm Zeta is centered well inland near 36.5N 81.5W at
29/1500 UTC, about 87 nm NE of Asheville, NC, moving NE at 45
kt. Estimated central pressure is 990 mb. Maximum sustained wind
speed is 45 kt with gusts to 55 kt. There is no convection
associated with Zeta over the Gulf. Strong, damaging wind gusts,
which could cause tree damage and power outages, will continue
to spread eastward across portions of the Carolinas and
southeastern Virginia through this afternoon due to Zetas fast
forward speed. Zeta is expected to have an even faster
northeastward motion later today, followed by a rapid east-
northeastward motion tonight and Friday.  On the forecast track,
the center of Zeta will move across the Mid-Atlantic states this
afternoon, and emerge over the western Atlantic by tonight. Zeta
is expected to become a non-tropical gale-force low later today.
The low should become absorbed by a frontal system over the
western Atlantic by Friday night. Please read the latest NHC
Forecast/Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT3.shtml.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave has an axis along 58W from 19N
southward, moving westward at 15 kt. Numerous moderate to
isolated strong convection is noted from 11N-17N between 56W-
62W.

A Caribbean Sea tropical wave has an axis along 65W from 22N
southward, moving westward at 10-15 kt. Scattered moderate
convection is noted from 12N-20N between 64W-69W. Upper-level
winds are expected to become more conducive for development of
this disturbance during the next couple of days, and a tropical
depression could form over the weekend or early next week while
the system moves westward across the central and western
Caribbean Sea. This system has a low chance of formation through
the next 48 hours and a medium chance through the next 5 days.

A Caribbean Sea tropical wave has an axis along 81W from 22N
southward, moving westward at 15 kt. Scattered moderate to
isolated strong convection is noted from 10N-16N between 79W-
83W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal plains of Sierra
Leone near 07N11W to 06N13W. The ITCZ continues from 06N13W to
05N31W to the coast of French Guiana near 05N52W. Scattered
moderate convection is noted along the ITCZ from 03N-10N between
27W-53W. Scattered moderate convection is also noted along the
monsoon trough and ITCZ from 01N-08N between 12W-23W.

GULF OF MEXICO...

At 1500 UTC, a cold front stretches from the western Florida
Panhandle near 30N87W to 24N91W. The front stalls from 24N91W
and extends southward to southern Mexico near 19N95W. A pre-
frontal trough is analyzed from the Florida Panhandle near
30N84W to 24N89W. Another trough extends across the eastern Bay
of Campeche from 22N91W to 19N91W. Showers are observed along
the front and pre-frontal trough in the eastern and central Gulf
from 19N-30N between 84W-93W. High pressure is building across
the western Gulf behind the cold front with fresh to strong WNW
winds especially off the coast of Texas eastward toward the
coast of Mississippi. Moderate to fresh SW winds are noted ahead
of the front. Light to gentle winds are in the southeastern
Gulf. Seas are averaging 6-9 ft across most of the basin with
upwards of 10 ft off the Louisiana coast. Seas are 3-4 ft in the
southeastern Gulf.

Zeta weakened to a tropical storm inland and is moving across
portions of Virginia and North Carolina. Zeta will continue
racing northeast away from the Gulf today and will become
extratropical this afternoon. Marine conditions along the
northern Gulf coast will quickly improve today. The cold front
will move quickly east and clear the basin by Fri. Fresh to
strong northwest winds behind the front will spread across the
Gulf through early Fri.

CARIBBEAN SEA...

See Tropical Waves section above for information on two tropical
waves crossing the Caribbean. These tropical waves have the
potential for tropical development this weekend or early next
week.

The eastern Pacific monsoon trough extends from the Colombia
coast near 11N75W to the coast of Costa Rica near 09N81W.
Scattered moderate convection is noted from 10N-12N between 75W-
79W. Moderate to fresh trades are noted in the eastern and
central Caribbean with light to gentle trades in the western
basin. Seas are averaging 3-6 ft.

A western Caribbean tropical wave is around 80W and will reach
Central America tonight. Another tropical wave along 58W will
cross into the eastern Caribbean through tonight, the central
Caribbean through Fri night then enter the western Caribbean
this weekend. Thunderstorms and gusty winds will accompany this
wave. This wave is expected to help low pressure to form in the
SW Caribbean this weekend. Gradually development is possible
thereafter, and a tropical depression could form early next week
while the system meanders in the SW Caribbean. This system has
the potential to bring heavy rainfall across portions of Central
America by the end of the weekend into early next week, mostly
from Honduras southward toward Costa Rica.

ATLANTIC OCEAN...

See the above tropical waves section for details on a tropical
wave approaching the Lesser Antilles. High pressure dominates
the rest of the basin anchored by a 1022 mb high near 29N44W.
Fresh to strong southerly winds are noted off the northeast
Florida coast in the western Atlantic. Otherwise, light to
gentle easterly winds are seen across the rest of the basin.
Seas are averaging 5-8 ft.

A tight pressure gradient between lower pressure in the
Caribbean and high pressure over the central Atlantic will lead
to moderate to fresh winds south of 27N today. A cold front will
move off the southeastern U.S. coast Thu night, with some strong
southwest winds ahead of it, north of about 29N. These winds
will spread east as the front reaches a line from Bermuda to the
Bahamas to Cuba this weekend and stalls. Some strong north winds
are possible behind the front north of about 29N this weekend. A
stronger cold front will sweep across the western half of the
area Sun night through Tue, followed by strong to near gale
force north to northeast winds and building seas.

$$
AReinhart
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