[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 040539
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Sat Oct 3 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
0520 UTC.

...SPECIAL FEATURES...

Tropical Storm Gamma is centered near 21.3N 88.0W at 03/0300 UTC
or 74 nm NNW of Tulum, Mexico moving NW at 6 kt. Estimated
central pressure is 990 mb. Maximum sustained wind speed is 50
kt with gusts to 60 kt. Numerous strong convection is within 170
nm in the NW quadrant. Scattered moderate to isolated strong
convection is also noted in the Yucatan Channel and south of
Cuba, N of 18N between 80W-87W. Seas up to 14 ft are along the N
Yucatan coast. Gamma is expected to turn toward the north-
northwest with decreasing forward speed is expected on Sunday,
followed by a turn to the west or west-southwest Sunday night or
Monday.  On the forecast track, the center of Gamma will move
offshore of the Yucatan Peninsula and over the southern Gulf of
Mexico on Sunday, and pass near or north of the northern coast
of the Yucatan Peninsula Monday and Tuesday. Little change in
strength is forecast during the next few days.  For marine
interests, strong winds and seas at least as high as 16 ft will
impact the Yucatan Channel through tonight. In the south-
central Gulf, a long fetch of persistent near-gale force NE
winds is already causing seas to 12 ft off the north coast of
Yucatan, along with rough surf conditions. Adverse marine
conditions will persist into mid week in the south-central Gulf
due to the expected track of Gamma. Please read the latest NHC
Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml
and Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details.

A tropical wave with an axis along 73W southward from 18N moving
W at 10 kt is producing scattered moderate convection from 11N-
16N between 71W-76W.  Environmental conditions are expected to
become more conducive for development, and a tropical depression
is likely to form during the early or middle portions of next
week while the system moves westward or west-northwestward at
about 15 mph across the central and western Caribbean Sea and
then into the southern Gulf of Mexico.  Locally heavy rainfall
and gusty winds will be possible across portions of Hispaniola,
Jamaica, Cuba, and the Cayman Islands during the next few days,
and interests on those islands should monitor the progress of
this disturbance. This system has a medium chance of development
through the next 48 hours and a high chance of formation through
the next 5 days.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 44W from 19N southward,
moving W at 10 kt. A 1010 mb low is along the wave near 12N44W.
Scattered moderate convection is noted from 12N-19N between 40W-
45W.  Some slow development of this system is possible during
the next couple of days while it moves west-northwestward or
northwestward at 10 to 15 kt.  Significant development is not
expected beyond that time due to the system moving into a region
of strong upper-level winds. This system has a low chance of
development over the next 48 hours and the next 5 days.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through coastal sections of Senegal
near 15N17W to 06N33W. The ITCZ continues from 06N33W to 09N43W
and from
09N44W to the coast of French Guiana near 04N52W. Scattered
moderate
convection is south of the monsoon trough from 02N-09N between
10W-26W.
Some scattered moderate convection is moving off the coast of
southern
Senegal and Guinea-Bissau. Scattered moderate convection is also
along
the ITCZ from 03N-08N between 33W-38W.

GULF OF MEXICO...

Please see the Special Features section above for information on
T.S. Gamma.

At 04/0300 UTC, a stationary front continues to linger off the
SW Florida coast near 26N81W to 24N85W. Scattered moderate
convection is within 80 nm of the front. High pressure over the
western and central Gulf is inhibiting any convection from
occurring over those areas. Moderate to strong N to NW winds
span across the eastern and central Gulf, cluding the eastern
half of the Bay of Campeche. Gentle easterly winds are off the
coasts of Texas through Alabama.  Seas are from 3-6 ft across
the northern and western Gulf with 9-14 ft across the south-
central Gulf near T.S. Gamma.

Tropical Storm Gamma will move to 21.8N 88.2W Sun morning, 22.2N
88.5W Sun evening, 22.1N 88.9W Mon morning, 21.8N 89.9W Mon
evening, 21.3N 90.9W Tue morning, and 20.7N 91.7W Tue evening.
Gamma will change little in intensity as it moves southwestward
through the eastern Bay of Campeche. A stationary front from SW
Florida near 26N81W to the SE Gulf near 23N86W will dissipate
late Sun into Mon, ahead of low pressure expected to move from
the northern Caribbean across western Cuba into the southeast
Gulf Tue. A cold front will move into the northern Gulf Mon,
then stall and dissipate over the central Gulf through mid week
as the low pressure moves northward.

CARIBBEAN SEA...

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

The monsoon trough extends across the southwest Caribbean from
13N74W to the coast of Costa Rica near 11N83W. Scattered
moderate convection is noted from 10N-14N between 74W-79W.
Isolated thunderstorms continue to impact the Lesser Antilles
westward into Puerto Rico. Thunderstorms are also noted in the
Gulf of Honduras. Gentle to moderate trade winds prevail across
most of the Caribbean with fresh winds near the Greater Antilles
and light winds in the SW Caribbean. Seas are from 3-6 ft across
most of the basin with upwards of 8 ft near the low along the
tropical wave.

Tropical Storm Gamma will continue to move NW into the south-
central Gulf, allowing winds and seas over the Yucatan Channel
to diminish through Sun. Meanwhile, another area of low pressure
is developing along a tropical wave south of Hispaniola. There
is a medium chance this low may form into a tropical depression
or tropical storm through late Mon as the low moves through the
NW Caribbean.

ATLANTIC OCEAN...

At 04/0300 UTC, a stationary front is draped off the Florida
coast from 31N79W to the coast near Melbourne, Florida at
29N80W. No significant convection is associated with this front
but fresh to strong NE winds are north of this front off the NE
Florida coast. The stationary front farther south extends from
31N74W to near West Palm Beach, Florida at 27N80W. Scattered
showers are within 50 nm of this front.  Fresh easterly winds
are noted N from Hispaniola to Cuba.

A surface trough in the central Atlantic extends from 30N46W to
24N51W. Scattered moderate convection is noted near this feature
from 27N-32N between 43W-51W.  Moderate to fresh winds are near
this trough. This system is expected to move toward the west-
southwest at around 10 kt, and some slow development is possible
during the next couple of days before it too encounters strong
upper-level winds. This system has a low chance of development
through the next 48 hours and the next 5 days. Ridging extends
across the rest of the basin anchored by a 1033 mb high west of
the Azores. Gentle to moderate winds prevail across the basin.

The southern stationary front will gradually dissipate through
early Sun. The northern stationary front will dissipate through
late Sun. Otherwise, the Bermuda High north of our area 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 or early
Mon, drift south through Tue then stall from 31N73W to near W
Palm Beach Florida by mid week.

$$
AReinhart
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