[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 030512
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Fri Oct 2 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
0450 UTC.

...SPECIAL FEATURES...

Recently upgraded Tropical Storm Gamma is centered near 19.1N
86.1W at 03/0300 UTC or 96 nm SSE of Cozumel, Mexico moving NW
at 8 kt. Estimated minimum central pressure is 998 mb. Maximum
sustained wind speed is 35 kt with gusts to 40 kt. Numerous
moderate to strong convection is within 200 nm in the W
semicircle, with some of the convection moving over the Yucatan,
Belize, and Honduras. Seas are up to 10 ft. A slower
northwestward motion is expected during the next couple of days,
followed by a turn to the west or west-southwest. On the
forecast track, the center of Gamma should be near the
northeastern Yucatan Peninsula on Saturday. Some strengthening
is expected before Gamma moves inland over the northeastern
Yucatan Peninsula on Saturday.  After landfall, slight weakening
or little change in strength is expected.  Gamma is expected to
produce heavy rainfall that could result in life-threatening
flash flooding over portions of the Yucatan Peninsula, far
western Cuba and well away from the center in the Mexican states
of Campeche, Tabasco, and northern Chiapas. Seas will build over
the far northwestern Caribbean and Yucatan Channel through
Saturday night, and in the south-central Gulf through early next
week. Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and the Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for
more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 40W from 18N southward,
moving W at 10-15 kt. A broad area of disorganized area of
scattered moderate to isolated strong convection is noted from
08N-18N between 31W-43W.

A Caribbean Sea tropical wave is along 69W from 18N southward,
moving W at 10 kt. An area of scattered moderate convection is
located from 13N-18N between 63W-71W. Locally heavy rainfall and
gusty winds are affecting portions of the ABC Islands, the
Lesser Antilles, the Virgin Islands, and Puerto Rico.
Environmental conditions are expected to become a little more
conducive for development, and a tropical depression could form
next week while the system moves westward or west-northwestward
at about 15 mph across the central and western Caribbean Sea.
There is a low chance of tropical cyclone formation with this
wave in the next 2 days and a medium chance in the next 5 days.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through coastal sections of Senegal
near 15N17W to 09N27W. The ITCZ continues from 09N27W to 07N38W,
and from 06N42W to the coast of Brazil near 03N51W. Scattered
moderate convection is noted along the ITCZ from 03N-09N between
41W-45W. Otherwise, convection near the ITCZ is associated with
the tropical wave along 40W.

GULF OF MEXICO...

At 0300 UTC, a stationary front extends from southwest Florida
near 26N81W to 22N90W. Scattered moderate convection is noted
within 100 nm south of the front. A stationary front farther
north extends off the Tampa Bay, Florida coast near 27N83W to
26N86W. No significant convection is associated with this front.
High pressure building across the western and central Gulf is
inhibiting any convection. Latest scatterometer data indicated
fresh to strong NNE winds across the central Gulf southward into
the Bay of Campeche. Moderate N winds are along the Florida
Panhandle with gentle easterly winds off the Texas coast. Seas
range 3-6 ft with upwards of 10 ft north of the Yucatan and in
the south-central Bay of Campeche.

Tropical Storm Gamma will move to 19.8N 86.9W Sat morning,
inland to 20.8N 87.6W Sat evening, and inland to 21.6N 88.0W Sun
morning. Gamma will move into the south-central Gulf to near
22.0N 88.3W Sun evening, 21.9N 88.9W Mon morning, and to 21.7N
90.0W Mon evening. Gamma will change little in intensity as it
moves through the far southwest Gulf through Tue. Meanwhile a
weak stationary front reaching from SW Florida to north of the
Yucatan peninsula will dissipate Sat ahead of Gamma. Another
stationary front from central Florida to the central Gulf will
dissipate Sun. A cold front will move into the northern Gulf and
stall through late Mon.

CARIBBEAN SEA...

Please see the Special Features section on information regarding
T.S. Gamma and the tropical waves section regarding the tropical
wave in the central Caribbean.

Scattered moderate convection is noted off the coast of Colombia
into the SW Caribbean, S of 14N between 72W-77W. Scattered
convection is moving across portions of Cuba and Jamaica
associated with T.S. Gamma. The latest scatterometer data
indicates that fresh to locally strong trade winds are off the
coast of Hispaniola and Puerto Rico. Otherwise, light to gentle
winds are in the SW Caribbean with moderate to fresh winds in
the central and eastern Caribbean. Seas are averaging 3 to 6 ft
with upwards of 9 ft near the Mona Passage.

Tropical Storm Gamma will move to 19.8N 86.9W Sat morning,
inland to 20.8N 87.6W Sat evening, inland to 21.6N 88.0W Sun
morning, 22.0N 88.3W Sun evening, then farther into the Gulf of
Mexico. Elsewhere, fresh to strong trades are expected over the
eastern and central Caribbean through Sun night. Winds and seas
will subside Mon and Tue across the basin.

ATLANTIC OCEAN...

A stationary front extends off the central Florida coast, from
31N78W to Melbourne, Florida near 28N80W. A stationary front
farther south extends along the northern Bahamas and the SE
Florida coast, from 31N74W to south of Miami near 26N80W.
Scattered moderate convection is within 40 nm of the southern
stationary front. A pre-frontal trough is analyzed from 26N78W
to central Cuba near 23N80W. Scattered moderate convection is
noted near this feature from 22N-25N between 77W-80W.

A mid-level trough near 64W is giving way to isolated
thunderstorms in the west-central Atlantic from 21N-28N between
60W-68W. A surface trough in the central Atlantic is noted along
46W from 24N-30N. Scattered moderate convection is noted near
this trough from 27N-33N between 40W-48W. Otherwise, surface
ridging is noted across the basin anchored by a 1033 mb high
near 41N37W. Light winds are noted in the western Atlantic off
the coasts of Florida and the Bahamas. Moderate to fresh
easterly winds are noted across the central and eastern Atlantic
strong N winds off the coasts of Western Sahara and Mauritania.
Seas are averaging 3-6 ft across the western and central
Atlantic.

A stationary front extending from 31N74W to 26N80W will
gradually dissipate Sat. A reinforcing cold front reaching from
31N78W to 29N80W will stall from near 31N79W to central Florida
by Sat afternoon, and then retreat northward as a warm front on
Sun. Meanwhile, the Bermuda High north of our area and lower
pressure in NW Caribbean associated with T.S. Gamma will support
moderate to fresh trades south of 22N, occasionally pulsing to
strong north of Hispaniola during the overnight hours through
Sun night. Looking ahead, a third weak front will move over the
Atlantic waters east of NE Florida late Sun and dissipate by
early Tue.

$$
AReinhart
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