[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 152301
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Sep 16 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 1800 UTC surface analysis and satellite imagery through
2230 UTC.

...SPECIAL FEATURES...

Hurricane Lee is centered near 37.9N 66.7W at 15/2100 UTC or 430
nm SSW of Halifax Nova Scotia, moving N at 17 kt. Estimated
minimum central pressure is 965 mb. Maximum sustained wind speed
is 70 kt with gusts to 85 kt. Scattered moderate to strong
convection is N of 36N between 65W-73W. Seas in excess of 12 ft
are expected within 440 nm NE quadrant, 480 nm SE quadrant, 500 nm
SW quadrant, and 410 nm NW quadrant, peaking to 45 ft. On the
forecast track, the center of Lee will continue to move farther
away from Bermuda and approach the coast of New England and
Atlantic Canada through Saturday. Lee is then expected to turn
toward the north-northeast and northeast and move across Atlantic
Canada Saturday night and Sunday. Swells generated by Lee are
affecting the northern Leeward Islands, the British and U.S.
Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos
Islands, the Bahamas, Bermuda, the east coast of the United
States, and Atlantic Canada. These swells are likely to cause
life-threatening surf and rip current conditions. Please consult
products from your local weather office for details.

Tropical Storm (T.S.) Margot is centered near 36.0N 37.9W at
15/2100 UTC or 530 nm W of the Azores, moving SE at 3 kt.
Estimated minimum central pressure is 990 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt. Seas of excess of 12 ft
are within 400 nm N semicircle, 260 NM SE quadrant, and 280 nm
quadrant, peaking to 22 ft. Scattered moderate convection is from
34N-39N between 30W-39W. Some additional weakening is forecast
during the next couple of days. Swells generated by Margot will
continue to affect the Azores for the next several days. These
swells are likely to cause life- threatening surf and rip current
conditions. Please consult products from your local weather office
for details.

Please read the latest High Sea Forecast issued by the Ocean
Prediction Center at website -
https://www.ocean.weather.gov/shtml/NFDHSFAT1.php for more
information on Lee and Margot.

Tropical Depression (T.D.) Fifteen is centered near 14.4N 43.8W
at 15/1500 UTC or 1015 nm E of the Lesser Antilles, and moving NW
at 10 kt. Estimated minimum central pressure is 1007 mb. Maximum
sustained winds are 30 kt with gusts to 40 kt. Seas are peaking
around 10 ft near and just N of the center. Scattered moderate
convection is from 08N-23N between 37W-47W. Gradual strengthening
is forecast during the next day or so, but a faster rate of
intensification is predicted later this weekend and early next
week. The depression is forecast to become a tropical storm on
Saturday and could become a hurricane late this weekend or early
next week.

Please read the latest HIGH SEAS FORECAST issued by
the National Hurricane Center at website -
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more
information.

For the latest NHC Forecast/Advisory and Public Advisories on all
three system, please visit www.hurricanes.gov for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is near 27W from 12N southward,
and moving west at 5 to 10 kt. Scattered moderate convection is
evident from 09N to 12N between 23W and 29W.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic near 14N17W to 13N36W.
Scattered showers are noted within 300 nm S of the boundary.
analysis.

The eastern end of the East Pacific monsoon trough is triggering
scattered showers and scattered thunderstorms across the
Caribbean waters north of Costa Rica and Panama.

...GULF OF MEXICO...

A stationary front extends eastward across the coast of Texas
New Orleans, Louisiana to the Florida panhandle. Scattered
showers and isolated thunderstorms are occurring near and up to 60
nm S of the front. A surface trough is analyzed over Bay of
Campeche with no significant convection. Elsewhere, a 1015 mb
high over the central Gulf is providing light to gentle with
locally moderate winds and seas of 1 to 3 ft across the entire
Gulf.

For the forecast, the weak ridge across the northern Gulf will dominate
the basin through the weekend, supporting mainly moderate or
weaker winds along with slight seas. Winds will pulse to moderate
to fresh W-NW of the Yucatan Peninsula each evening through the
weekend. A weak cold front may drop into the NE Gulf early next
week with new high pres building in behind it.

...CARIBBEAN SEA...

Refer to the Monsoon Trough/ITCZ section for convection in the
basin. The presence of Hurricane Lee at the northwestern Atlantic
is supporting a modest trade-wind pattern across much of the
basin. Fresh to strong easterly winds and seas of 5 to 7 ft are
evident at the south-central basin north of Colombia and
northwestern Venezuela. Moderate to fresh ENE to ESE winds and 2
to 4 ft seas are found at the north-central basin. Light to
gentle winds and seas at 1 to 3 ft are present north of Costa Rica
and Panama. Gentle to moderate ENE to ESE winds and 3 to 5 ft
seas prevail for the rest of the basin.

For the forecast, northerly swell affecting the NE Caribbean Passages
will gradually subside tonight, then may build again early next
week due to T.D. Fifteen which is forecast to remain NE of the
area. Otherwise, moderate to fresh trades will dominate the
Central Caribbean, locally strong, with gentle to moderate winds
elsewhere.

...ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section, for details about
Hurricane Lee, T.S. Margot, and T.D. Fifteen.

Convergent southerly winds feeding toward Hurricane Lee are
causing scattered moderate convection north of Puerto Rico and
the Virgin Islands from 20N to 30N between 60W and 68W. An
elongated upper-level low near 24N55W is generating scattered
moderate convection from 19N to 30N between 46W and 53W. Refer to
the Monsoon Trough/ITCZ and Tropical Waves sections for additional
weather in the Atlantic Basin.

North of 28N, moderate to fresh SW to NW winds and seas of 12 to
16 ft are noted between 58W and 75W, and gentle to moderate NE to
NW winds and seas at 8 to 11 ft are noted between 75W and the
Georgia-Florida coast. Light to gentle winds and 8 to 11 ft seas
in moderate to large northerly swell dominate from 20N to 28N
and W of 50W. At the central and eastern Atlantic outside the
direct impact of T.D. Fifteen, moderate to fresh winds and seas
of 8 to 10 ft exist N of 30N between 35W-50W. Otherwise, gentle to
moderate NNE to E winds and 5 to 7 ft seas in mixed northerly and
northeasterly swells are seen from north of 14N between the
Africa coast and 50W, including the Canary and Cabo Verde Islands.
Gentle to moderate S to SW winds and seas of 5 to 7 ft in
moderate southerly swell are evident from the Equator to 17N
between the central Africa coast and 50W. Light to gentle winds
and seas at 5 to 8 ft in moderate NW swell prevail for the rest of
the Atlantic Basin.

For the forecast W of 55W, Hurricane Lee will continue to move N
away from the area, while associated large northerly swell
gradually decays through the weekend. T.D. Fifteen will move to
16.7N 45.0W Sat morning, strengthen to a tropical storm near 18.5N
46.6W Sat afternoon, 20.4N 48.4W Sun morning, 22.0N 50.1W Sun
afternoon, strengthen to a hurricane near 23.6N 51.7W Mon morning,
and 25.1N 53.6W Mon afternoon. Fifteen will change little in
intensity as it moves to 28.0N 57.3W Tue afternoon. Otherwise,
high pres will prevail across the waters through the weekend. A
weak cold front may move off the SE U.S. coast early next week
with new high pres building down behind it.

$$
ERA
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