[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 111107
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...SPECIAL FEATURES...

Hurricane Lee is near 23.1N 62.6W at 5 AM EDT, or about 340 miles
N of the northern Leeward Islands, moving northwest at 6 kt.
Maximum sustained winds are 105 kt with gusts to 130 kt. Minimum
central pressure is 950 mb. Peak seas are estimated near 46 ft
near the center. Satellite imagery overnight has shown a ragged
eye filling in with mid level clouds in recent hours. Numerous
moderate to scattered strong convection is within 60 nm NW and 90
nm SE of the center. Scattered moderate isolated strong convection
is seen elsewhere from 20N to 25N between 59W and 66W. Lee is
expected to continue a slow motion toward the NW for the next 48
hours, with modest strengthening likely. By Wed, Lee is expected
to begin to turn northward and will exit the region to the north
of 31N Thu night. 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.
Large swell generated by Lee is currently affecting the waters
and coasts of the Islands of the NE Caribbean, and extend west
and northwestward to the central Bahamas and the waters to 76W.
These swells are likely to cause large and dangerous surf and
life-threatening rip current conditions along these coastlines,
and will spread to the Florida coast and SE U.S. coastlines by
Tue. Dangerous surf and rip currents 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.

Storm Margot is near 25.3N 40.0W at 5 AM EDT, or about 1215 miles
NW of the Cabo Verde Islands, moving north at 7 kt. Maximum
sustained winds are 55 kt with gusts to 65 kt. Minimum central
pressure is 996 mb. Peak seas are estimated around 21 ft near the
center. Scattered to numerous moderate to strong convection is
within 90 nm NW and 45 nm SE of the center. Similar convection
is NE of the center, from 26N to 29.5N between 32W and 38W.
Margot is expected to continue moving northward for the next
few days, reaching hurricane strength this evening or tonight,
then exiting the region to the north of 31N Tue evening.

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 along 20W, to the south of
19N, and moving west around 5 kt. Scattered moderate isolated
strong convection is from 07N to 15.5N between the Senegal-Guinea
Bissau coast and 27W. 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 analyzed along 30W, south of
16N, moving westward around 10 kt. A 1012 mb low pressure center
(Invest AL97) is near 13N 30W. Scattered moderate isolated strong
convection is noted from 11N to 15N between 31W and 35W. This
system is forecast to merge with the aforementioned tropical wave
to the east 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
13N30W to 15.5N35W. Other than the convection associated with the
two tropical waves, widely scattered moderate convection is noted
from 08N to 14.5N between 44W and 50W. No ITCZ is present based
on the latest analysis.

...GULF OF MEXICO...

A very weak stationary front persists from the Florida Panhandle
through the north-central Gulf to near Corpus Christi, Texas.
Widely scattered showers and mild thunderstorms are seen near and
up to 60 nm south of the front, to the E of 90W. A surface trough
that has moved off the west coast of the Yucatan Peninsula is
triggering scattered showers and thunderstorms across the west and
central Bay of Campeche. A modest surface ridge is supporting
gentle to locally moderate E to SE 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. Scattered showers and thunderstorms can be expected
across the western Yucatan and eastern Bay of Campeche each late
afternoon and evening.

...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 supporting scattered showers and isolated
thunderstorms from the Gulf of Honduras southeastward across
the SW Caribbean waters to the coasts of Panama and Colombia. 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 NE swell in the
NE Caribbean Passages. 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 this evening before Lee in
the Atlantic disrupts the pressure pattern. Large easterly swell
from Lee will gradually become NE and then N today 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.

Outside of the weather described above associated with the
tropical waves and tropical cyclones, limited convection is noted
across the basin. Weak low pressure near 14.5N47.5W is producing a
small cluster of scattered moderate convection.

Outside the direct impact of Lee and Margot, a modest 1025 mb
high is across the north Atlantic near 40N53W is supporting
gentle to moderate NE to SE winds and seas of 6 to 12 ft in mixed
swell 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 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 9 ft seas in mixed moderate to large swells
prevail.

For the forecast W of 55W, Hurricane Lee is expected to maintain
a slow NW motion and strengthen modestly through Tue, then begin a
gradual turn toward the N on Wed, and exit the region Thu night.
Lee is expected to reach near 23.5N 63.5W this afternoon, near
24.0N 64.8W Tue morning, near 24.5N 65.8W Tue afternoon, near
25.1N 66.7W Wed morning, near 26.1N 67.3W Wed afternoon, and near
27.6N 67.6W Thu morning. Large E to SE swell dominating the waters
east of 76W early this morning will continue to propagate
westward across the Atlc, reaching the NW Bahamas and 78W late
this afternoon or evening, and the Florida and Georgia coasts Tue
afternoon. Large swell from Lee will dominate regional waters Tue
night through Fri.

$$
Stripling
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