[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 110556
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Sep 11 2023

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 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...SPECIAL FEATURES...

Hurricane Lee is centered near 22.6N 62.2W at 11/0300 UTC or 270
nm N of the Northern Leeward Islands, and moving NW at 7 kt.
Estimated minimum central pressure is 950 mb. Maximum sustained
winds are 105 kt with gusts to 130 kt. Peak seas range from 39 to
41 ft near the center. Numerous moderate to scattered strong
convection is within 70 nm of the center. Scattered moderate
convection is seen farther north from 24N to 26N between 58W and
65W, and farther east from 20N to 24N between 58W and 61W. Lee is
expected to continue its current motion for the next few days,
passing well north of the northern Leeward Islands, Virgin
Islands, and Puerto Rico during the next day or two. Lee remains a
category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale.
Additional strengthening is forecast for the next day or so, then
followed by a gradual weakening trend. Swells generated by Lee are
affecting the Leeward and Virgin Islands, Puerto Rico, Hispaniola,
the Turks and Caicos Islands, the Bahamas, and Bermuda. These
swells are likely to cause life-threatening surf and rip current
conditions. Dangerous surf and rip currents have begun to reach
portions of the southeast U.S. East Coast and are forecast to
worsen and spread northward along much of the U.S. East Coast
during the next couple of days. Please consult products from your
local weather office.

Tropical Storm Margot is centered near 24.6N 39.9W at 11/0300 UTC
or 1030 nm WNW of the Cabo Verde Islands, and moving N at 7 kt.
Estimated minimum central pressure is 996 mb. Maximum sustained
winds are 55 kt with gusts to 65 kt. Peak seas range from 19 to
21 ft near the center. Scattered moderate convection is within 50
nm of the center. Similar conditions is found near a banding
feature farther northeast and southeast from 20N to 34N between
34W and 38W. Margot is expected to continue its current motion
for the next several days. Additional strengthening is forecast,
and Margot is likely to become a hurricane on Monday.

Please read the latest HIGH SEAS FORECAST issued by the National
Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC
Forecast/Advisory and Public Advisory on Lee and Margot at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave is near 19W from 18N
southward, and moving west around 5 kt. Widely scattered moderate
convection is from 08N to 15N between the Senegal-Guinea Bissau
coast and 24W, including the southern Cabo Verde Islands.
Environmental conditions appear conducive for gradual development
of this system during the latter part of this week, and a tropical
depression could form by next weekend as it moves westward to
west-northwestward over the central tropical Atlantic. There is a
low chance of tropical cyclone formation during the next 2 days
and a medium chance from 3 to 7 days.

An eastern Atlantic tropical wave is near 29W from 18N southward
through a 1012 mb low (Invest AL97) near 14N29W, and moving
westward around 10 kt. Widely scattered moderate convection is
noted from 09N to 15N between 27W and 34W. This system is
forecast to merge with the aforementioned tropical wave upstream
in a couple of days. As a result, there is a low chance of
tropical cyclone formation during the next 7 days.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic near Nouakchott, Mauritania
then reaches southwestward through the low (Invest AL97) near
14N29W to 15N34W. It resumes farther west from 14N41W to 08N49W.
Other than convection associated with the two tropical waves,
there is no additional convection near the monsoon trough. No ITCZ
is present based on the latest analysis.

...GULF OF MEXICO...

A very weak stationary front curves westward from the Florida
Panhandle through the north-central Gulf to near Corpus Christi,
Texas. Isolated thunderstorms are seen near and up to 110 nm south
of the front. A surface trough moving off the west coast of the
Yucatan Peninsula is triggering scattered showers and
thunderstorms at the central and eastern Bay of Campeche. A modest
surface ridge is supporting gentle to locally moderate E to SSE
winds and 2 to 3 ft seas for the entire Gulf.

For the forecast, the surface ridge will continue to dominate the
Gulf waters through most of this week with light to moderate
winds.

...CARIBBEAN SEA...

Please read the SPECIAL FEATURES section about large swell
generated by Major Hurricane Lee impacting the northeast
Caribbean islands.

An upper-level trough running east-southeastward from western
Cuba to Hispaniola is inducing widely scattered showers and
isolated thunderstorms from the Gulf of Honduras eastward across
Jamaica to Hispaniola. The presence of Hurricane Lee in the
Atlantic is sustaining a weak pressure gradient across the basin.
Light to gentle winds and 4 to 6 ft seas in moderate easterly
swell are present at the northeastern basin, except 6 to 9 ft seas
in large easterly swell near the Virgin Islands and Anguilla.
Light to gentle winds and seas at 3 to 5 ft in moderate easterly
swell are found near Costa Rica and Panama. Gentle to moderate
with locally fresh ENE to ESE winds and seas of 3 to 6 ft prevail
for the rest of the basin.

For the forecast, moderate to fresh trade winds will continue in
the central and eastern basin through Mon before Lee in the
Atlantic disrupts the pressure pattern. Large easterly swell from
Lee is dominating the Atlantic waters from the northern Leeward
Islands to the Central Bahamas. This large swell from Lee will
gradually become NE and then N tonight through Thu, and move
through the Caribbean Passages into the Caribbean waters between
the Leeward Islands and the Mona Passage, before diminishing
significantly Thu night through Fri.

...ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section at the beginning for
information about Hurricane Lee and Tropical Storm Margot.

An upper-level trough near 27N44W is causing isolated
thunderstorms from 25N to 29N between 46W and 51W. A surface
trough near 14N48W is generating similar conditions within 100 nm
of 14N49W. Refer to the Tropical Waves section for additional
convection in the Atlantic Basin.

Outside the direct impact of Lee and Margot, a modest 1022 mb
high near 32N32W is supporting gentle to moderate NE to SE winds
and seas of 6 to 12 ft in mixed large swells north of 20N between
30W and 70W. Farther west, light to gentle with locally moderate
ENE to ESE winds exist north of 20N between 70W and the Georgia-
Florida coast. Near the Canary Islands, gentle to moderate NNE to
NE trades and 4 to 6 ft seas are evident north of 18N between the
northwest Africa coast and 30W. To the south, light to gentle with
locally moderate monsoonal winds and seas at 4 to 6 ft in
mixed moderate swells are noted from 07N to 18N/20N between the
central Africa coast and 35W, including the Cabo Verde Islands.
For the tropical Atlantic from 08N to 20N between 35W and the
Lesser Antilles, light to gentle winds and 6 to 10 ft seas in
mixed moderate to large swells prevail. Gentle to moderate with
locally fresh southerly winds and 6 to 9 ft seas in large
southerly swell dominate the remainder of the Atlantic Basin.

For the forecast W of 55W, Hurricane Lee will reach near 23.1N
63.1W Mon morning, 23.6N 64.4W Mon evening, and 24.1N 65.5W Tue
morning. Afterward, it will move to near 24.6N 66.4W Tue evening,
25.3N 67.2W Wed morning, and 26.5N 67.7W Wed evening. Lee is
expected to turn northward and enter the northwestern Atlantic
Wed night through Thu night. Large E to SE swell dominating the
waters east of 75W tonight will continue to propagate westward
across the Atlantic, reaching the northwest Bahamas and 78W early
Mon evening, and the Florida coasts Tue afternoon. This swell
will persist in these waters Tue night through Fri.

$$

Forecaster Chan
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