[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131136
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Sep 13 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...

Major Hurricane Lee is near 25.7N 67.1W at 5 AM EDT, or about 475
miles SSW of Bermuda, moving northwest at 5 kt. Maximum sustained
winds are 100 kt with gusts to 120 kt. Minimum central pressure
is 948 mb. Lee has shown a very ragged and somewhat elongated eye
overnight. Numerous moderate to strong convection is noted within
about 90 nm of center, except 30 nm across the NW quadrant. Seas
in excess of 12 ft extend 375 nm NE and SW, 450 nm NW and 315 nm
SE quadrants of the center of Lee with maximum seas estimated at
45 ft. Lee is expected to begin to turn more northward today and
tonight and move beyond 31N night. While the core of the
hurricane is forecast to pass west of Bermuda, the large wind
field of the storm is likely to bring tropical storm force winds
and heavy rainfall to the island late tonight and early Thu. Lee
is a category 3 hurricane on the Saffir-Simpson Hurricane Wind
Scale. Some slow weakening is forecast during the next 48 hours
though the wind field is forecast to remain large. Swells
generated by Lee are propagating in all directions, and are
affecting the waters and Islands of the NE Caribbean, Hispaniola,
the Turks and Caicos Islands, the Bahamas, Florida and the SE and
mid Atlantic coasts of the U.S., and Bermuda. These swells are
likely to cause large and dangerous surf and life-threatening rip
current conditions. Hurricane swell and associated surf along the
coasts from Florida to the Mid Atlantic states will increase
today, and peak in size across the Bahamian and Caribbean Islands
and waters to the S and SW of Lee today through night. This will
maintain very dangerous surf and rip currents conditions along
much of the Carribbean, U.S. East Coast, and Atlantic Canadian
coastlines during the next couple of days. Please consult products
from your local weather office.

Hurricane Margot is near 33.6N 40.0W at 5 AM EDT, moving north at
10 kt. Maximum sustained winds are 75 kt with gusts to 90 kt.
Minimum central pressure is 975 mb. Scattered to numerous
moderate isolated strong convection is seen in satellite imagery
within 180 nm SE and 60 nm NW of the center. Seas in excess of 12
ft extend within 300 nm NE, 320 nm SE, 240 nm SW, and 270 nm NW
quadrants of the center, with maximum seas estimated at 32 ft.
Margot is moving toward the north. A turn toward the north- east
at a slower forward speed is expected beginning late Thu. A
meandering northward motion is then expected on Thursday night and
Friday. Margot's track beyond Friday is unusually uncertain, but
a slow meandering motion is generally expected into the weekend.
Slight fluctuations in intensity, up or down, are possible during
the next several days. Swells generated by Margot will begin to
affect the Azores on Wednesday. These swells are likely to cause
life- threatening surf and rip current conditions. Please consult
products from your local weather office.

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 tropical wave is analyzed along 25W south of 18N, moving west
at 10 kt. Scattered moderate isolated strong convection is noted
from 04.5N to the Cabo Verde Islands between 23W and 28W. A 1009
mb surface low (AL97) lingers W of this area near 12N33W.
Disorganized showers and thunderstorms continue near this low
center from 09N to 13N between 30W and 35W. As the tropical wave
along 25W moves westward during the next few days and interacts
with this broad low pressure, some gradual tropical development
of this system is expected, while it moves W-NW to NW at 10 to 15
mph. A tropical depression is likely to form from this system by
this weekend over the central Atlantic. This system has a medium
chance of development through 48 hours, and a high chance through
7 days.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic Ocean through the coast
of Senegal near 14N17W, then continues to 1009 mb low pressure
near 12N33W to a broad 1011 mb low pressure area near 14.5N48.5W.
Scattered moderate convection is noted within about 60 nm S of a
line from 11N28W to 08N32W to 07N39W. Numerous moderate to strong
convection is seen from the African coast to 16W, between 04N and
09N. Scattered moderate to strong convection is observed from 07N
to 11.5N between 35W and 43W.

...GULF OF MEXICO...

High pressure of 1014 mb located over N Florida and dominates the
basin. This pattern is maintaining light winds and slight seas
across the Gulf waters. Scattered showers and a few thunderstorms
are evident across the coastal waters of the western Florida
Panhandle, and across the Bay of Campeche.

For the forecast, high pressure will reorganize across the NW
Gulf by tonight and persist for several days. This will maintain a
weak ridge across the northern Gulf throughout the forecast
period, supporting mainly light to gentle winds N of 24N and
gentle to moderate winds S of 24N. Moderate return flow will
develop across the W and SW Gulf Thu night. Scattered
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.

The subtropical ridge that is normally north of the region is disrupted
by Hurricane Lee, resulting in gentle to moderate winds across
the basin. Northerly swell generated by Lee continues to
propagate through the passages of the NE Caribbean, including the Anegada
and Mona Passages. Swell has increased overnight, with buoys along
the N and NW coast of Puerto Rico reporting seas to 8 ft this
morning, with plumes of 5 to 7 ft combined seas extending south
through the passages across the northeast Caribbean. Seas of 2-4
ft are noted elsewhere. A trailing convergence band of Lee
extends across far eastern Dominican Republic and the Mona
Passage. Scattered showers and thunderstorms also persist near the
coasts across the Gulf of Honduras.

For the forecast, Hurricane is expected to turn toward the N today
through Thu and exit the region, passing W of Bermuda. Large N-NW
swell across the adjacent Atlantic waters will move through the
NE Caribbean Passage through early Thu before gradually
diminishing through Thu night and then decreasing quickly Fri.
Moderate to locally fresh trade winds will return to the Caribbean
on Fri.

...ATLANTIC OCEAN...

Please see the Special Features section for information about
Major Hurricane Lee and Hurricane Margot, and the tropical waves
section for information on AL97.

High pressure is displaced to the NE of Bermuda due to Margot and
Lee, producing moderate to fresh NE to E winds from the waters W
of Margot westward to the N of Lee. Large swell from these
hurricanes is producing seas of 8 to 12 ft and larger across this
area. To the S, gentle trade winds prevail from 55W to the
tropical wave along 25W. An upper level trough extends into the
tropics between 40W and 55W, and is supporting scattered moderate
convection from 14N to 23N between 35W and 50W.

To the W of Lee, E to SE swell is increasing this morning. Florida
coastal buoys are reporting 4 to 5 ft seas this morning, but are
expected to increase to 5 to 8 ft by late afternoon. Dangerous
surf conditions will prevail along Atlantic coastlines today
through at least Thu due to this large and fast moving hurricane
swell.

For the forecast west of 55W, Hurricane Lee will begin to turn
northward today through Thu, reaching near 26.6N 67.6W this
afternoon, near 28.4N 68.1W Thu morning, near 30.5N 68.3W Thu
afternoon, passing W of Bermuda near 33.0N 68.0W Fri morning, then
continue moving northward into the weekend. Large swell from Lee
will propagate in all directions and dominate the regional waters
W of 55W through Fri.Fri.

$$
Stripling
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