[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221757
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Fri Sep 22 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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Tropical Storm Ophelia is centered near 32.7N 76.0W at 22/1800
UTC or 130 nm SE of Cape Fear North Carolina, moving NNW at 10
kt. Estimated minimum central pressure is 992 mb. Max mum
sustained wind speed is 50 kt with gusts to 60 kt. Maximum
sustained wind speed is 45 kt with gusts to 55 kt. Seas 12 ft or
greater are occurring within 240 NM NE quadrant, 120 NM SE
quadrant, 160 NM SW quadrant, and 180 NM NW quadrant with peak
seas to 20 ft. Scattered moderate and isolated strong convection
is noted within 180 NM in the N semicircle. A north to north-
northwest motion is expected during the next couple of days. On
the forecast track, the center of the low will approach the
coast of North Carolina tonight, and then move across eastern
North Carolina, southeastern Virginia, and the Delmarva
Peninsula Saturday and Sunday. Some strengthening is forecast
before landfall, and the low is expected to become a tropical
storm before it reaches the coast of North Carolina. Regardless
of whether it becomes a tropical storm, the system is expected
to bring tropical storm conditions to portions of the southeast
and mid-Atlantic coasts. 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
Sixteen NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

Invest 90L in the Central Tropical Atlantic: The axis of a
tropical wave is analyzed along 33W with a 1009 mb low centered
at 14N33W. Maximum winds are currently 25 kt and peak seas are
up to 9 ft. Scattered moderate convection is noted from 14N-20N
between 28W-35W. Shower and thunderstorm activity associated
with this area of low pressure continues to show signs of
organization. Further development is expected, and a tropical
depression is likely to form during the next couple of days
while the system moves generally westward at 10 to 15 kt. The
system is then expected to turn west-northwestward early next
week as it moves over the central tropical Atlantic. The
formation chance through 48 hours is high. Please see the latest
Tropical Weather Outlook at www.hurricanes.gov for more
information.

...TROPICAL WAVES...

Please see the Special Features Section for details on the
tropical wave (Invest 90L) along 33W.

A central Atlantic tropical wave has its axis along 57W, south
of 22N, moving westward around 10 kt. Scattered moderate
convection is noted south of 12N west of 57W.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Senegal near 14N16W and continues westward to the aforementioned
low pressure near 14N33W, before terminating near 10N43W. The
ITCZ then extends from 10N43W to 10N51W. Scattered moderate
convection is noted from 14N-20N between 28W-35W.

GULF OF MEXICO...

Weak high pressure over the lower Mississippi Valley is
supporting only light to gentle NE to E breezes and slight seas
across most of the basin this afternoon. Isolated moderate
convection is noted in the E Gulf between 24N-27N and east of
87W.

For the forecast, the weak high pressure over the lower
Mississippi Valley will control the weather pattern across basin
through early next week. This will support mostly gentle to
moderate east to southeast winds and slight seas, except for
moderate to fresh winds pulsing offshore the western Yucatan
Peninsula in the evenings.

CARIBBEAN SEA...

Weak surface ridging north of the Caribbean is forcing only
gentle to moderate trades across the Caribbean, except fresh NE
winds within 90 NM of the coast of Colombia. Seas are 4-6 ft in
the central Caribbean and 2-4 ft in the W and E Caribbean. No
deep convection is noted today over the Caribbean.

For the forecast, the moderate to fresh trade winds in the
central Caribbean will change little through the next few days
as high pressure remains centered over the central Atlantic.
Fresh to strong trade winds will pulse offshore of northern
Colombia and northwest Venezuela during mainly the overnight and
early morning hours into early next week. Looking ahead,
combined seas will build northeast of the Leeward Islands
starting Mon ahead of low pressure moving westward across the
tropical Atlantic, possibly as the next tropical cyclone.

ATLANTIC OCEAN...

Please see the Special Features section section above for
information on Tropical Storm Ophelia and Invest 90L.

A trough extends from Tropical Storm Ophelia south-southwestward
to 24N79W. Scattered moderate convection is noted from 21-25N
between 68W-79W. Elsewhere, ridging extends across the Atlantic
along roughly 30N. Between the ridge and the monsoon
trough/ITCZ, the trades are gentle to moderate with seas 6-8 ft.
Winds and seas are higher in the vicinity of Potential Tropical
Cyclone Sixteen and Invest 90L. Isolated moderate convection is
noted from 21N-26N between 47W-56W in association with an upper-
level trough.

For the forecast west of 55W, Ophelia will move to 33.2N 76.3W
this evening, then continue to move north of the area and inland
across coastal North Carolina early Sat. A weak ridge will build
in the wake of Ophelia off northeast Florida through early next
week, although a trough will persist across the Bahamas. Looking
ahead, combined seas will build northeast of the Leeward Islands
starting Mon ahead of low pressure moving westward across the
tropical Atlantic, possibly as the next tropical cyclone.

$$
Landsea
This weather bulletin was brought to you by:
www.nashvilleweather.net