[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151243 AAB
TWDAT

Tropical Weather Discussion...Updated
NWS National Hurricane Center Miami FL
1205 UTC Fri Sep 15 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.

Updated for 1200 UTC information on Special Features

Based on 0600 UTC surface analysis and satellite imagery through
1050 UTC.

...SPECIAL FEATURES...

Hurricane Lee is centered near 35.1N 67.0W at 15/1200 UTC or 400
nm SSE of Nantucket Massachusetts, moving N at 14 kt. Estimated
minimum central pressure is 962 mb. Maximum sustained wind speed
is 75 kt with gusts to 90 kt. Peak seas over the SW N Atlantic
waters S of 31N are 18 ft, but seas are higher N of this area,
up to 45 ft per the NWS Ocean Prediction Center. Scattered
moderate convection is from 34N to 44N between 60W and 73W. On
the forecast track, the center of Lee will continue to move
farther away from Bermuda this morning and approach the coast of
New England and Atlantic Canada today and Saturday. Lee is then
expected to turn toward the north-northeast and northeast and
move across Atlantic Canada Saturday night and Sunday. Little
change in strength is expected through tonight. Lee is forecast
to become post-tropical and begin weakening by Saturday, but it
is still expected to be a large and dangerous storm when it
reaches eastern New England and Atlantic Canada.

Tropical Storm Margot is centered near 36.7N 38.6W at 15/0900
UTC or 560 nm W of the Azores, moving ESE at 3 kt. Estimated
minimum central pressure is 984 mb. Maximum sustained wind speed
is 60 kt with gusts to 75 kt. Scattered moderate convection is
from 35N to 40N between 21W and 40W. Margot is expected to make a
slow clockwise loop during the next day or two. Then, a faster
northeastward motion is forecast by Monday. Some additional
weakening is forecast during the next couple of days.

AL97 Gale Warning...Showers and thunderstorms have become better
organized in association with a broad low pressure area located
about midway between the Cabo Verde Islands and the Lesser
Antilles. Environmental conditions remain conducive for
additional development, and this system is expected to become a
tropical depression within the next day or so while it moves
west-northwestward to northwestward at 10 to 15 kt across the
central tropical Atlantic.  A gale warning has been issued,
starting this afternoon. Current peak seas based on earlier
altimeter data are 10 to 11 ft. Please refer to the latest NHC
Tropical Weather Outlook at www.hurricanes.gov for more details.

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 Lee
and Margot NHC Forecast/Advisory and Public Advisories at
www.hurricanes.gov for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from 12N17W to 13N35W to 13N52W. Aside
from the convection associated with AL97, scattered moderate
convection is from 02N to 11N between 20W and 36W.

...GULF OF MEXICO...

A weak pressure gradient is across the Gulf of Mexico supporting
light to gentle variable winds and slight seas basin-wide, except
for moderate NE to E winds in the Bay of Campeche.

For the forecast, weak surface ridging across the northern Gulf
will dominate the basin throughout Tue, supporting mainly light to
gentle variable winds N of 24N and moderate to locally fresh NE
to E winds in the Bay of Campeche off the Yucatan Peninsula.
Scattered thunderstorms can be expected across the western Yucatan
and eastern Bay of Campeche each late afternoon and evening
through the period. Otherwise, slight seas are forecast basin-wide
through Tue night.

...CARIBBEAN SEA...

Moderate to fresh trade winds are in the central and portions of
the SW Caribbean along with slight seas. Light to gentle variable
winds are across the remainder basin. Otherwise, moderate seas
associated with the passage of Hurricane Lee through the SW N
Atlantic waters is still supporting moderate seas in the NE
Caribbean passages.

For the forecast, large swell affecting the NE Caribbean Passages
will gradually decrease by this evening, however moderate seas
are forecast to prevail through the middle of next week due to a
possible tropical cyclone that will move NE of the area Tue and
Wed. Otherwise, moderate trade winds will dominate the central and
portions of the SW Caribbean through Tue. Gentle to locally
moderate winds are forecast elsewhere.

...ATLANTIC OCEAN...

Please, read the SPECIAL FEATURES section, for details
about Hurricane Lee, Hurricane Margot, and Invest AL97.

Hurricane Lee is N of the area near 34.4N 67.5W at 5 AM EDT, and
is moving north at 14 kt. Maximum sustained winds are 75 kt with
gusts to 90 kt, and the minimum central pressure is 957 mb. Swell
with seas to 18 ft are affecting the SW N Atlc waters. Moderate to
fresh NE to E winds and moderate seas are elsewhere across the
subtropical Atlc waters E of 50W.

For the forecast W of 55W, Lee will move to 36.8N 67.0W this
afternoon, 40.3N 66.7W Sat morning, weaken as an extratropical
cyclone near 43.4N 66.4W Sat afternoon, inland to 46.3N 64.8W Sun
morning, 49.3N 61.1W Sun afternoon, and 52.2N 55.0W Mon morning.
Lee will dissipate early Tue. Long-period swell generated by Lee
is expected to impact the waters north and east of the Bahamas
through Sun morning. High pressure will build briefly across the
area Sun into Mon. Low pressure across the central Atlantic, AL97,
is expected to approach the ENE part of the area Mon, possibly as
a tropical cyclone, and track northwestward over that same area
through Wed leading to a significant increase in winds and seas.

$$
Ramos/JRL
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