[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 070412
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Wed Dec 7 2022

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 0000 UTC surface analysis and satellite imagery through
0400 UTC.

...SPECIAL FEATURES...

Central Atlantic Storm Warning:

A large area of low pressure located over the central subtropical
Atlantic about 670 nautical miles ESE of Bermuda centered near
29N53W with a minimum central pressure of 994 mb, continues to
produce a broad area of showers and thunderstorms in the northern
semicircle of the low. Environmental conditions appear marginally
conducive for development and a subtropical or tropical storm
could form in the next couple of days. By Thursday night or
Friday, the low will move northeastward over cooler waters and
interact with a mid-latitude trough, limiting subtropical or
tropical development of the system.

Regardless of development, this system is already producing a
large area of gale force winds and will strengthen to storm force
by 06 UTC. Storm force winds will initially occur in the NW
quadrant, surrounded by gales that extend up to 300 nm north and
240 nm west of the low pressure center. Strong gale to storm force
winds are expected to continue into Friday. Peak seas are
currently 25 ft near 31N53W, on a building trend through
Wednesday. Seas 12 ft or greater extend north of 22N, between 44W
and 63W. This area of very rough seas will continue to expand
through Wed. More information about this system, including the
official storm warning, can be found in High Seas Forecasts issued
by the National Weather Service at:
http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

...MONSOON TROUGH/ITCZ...-

The monsoon trough extends from the coast of Guinea near 10N14W to
08N17W. The ITCZ continues from 08N17W to 08N46W. Isolated
moderate convection is observed within 210 nm of the ITCZ.

GULF OF MEXICO...

A 1023 mb surface high pressure centered south of the Florida Big
Bend is dominating the Gulf of Mexico. Patchy fog is being
reported along the coast Alabama and the Florida Panhandle, which
will likely become more dense over the next six hours or so.
Light to gentle winds are observed in the NE Gulf near the high
pressure center. Moderate to fresh easterlies are observed in the
southern Gulf, while moderate to fresh SE winds are observed in
the western Gulf. Seas are 1-3 ft in the NE Gulf and 3-5 ft
elsewhere.

For the forecast, high pressure will meander about the NE Gulf
and North Florida into Sat. Dense fog will begin to dissipate by
mid-morning Wed. Moderate to fresh return flow will prevail W of
92W through Wed night then diminish into Sat night.

CARIBBEAN SEA...

The gradient between high pressure near Florida and lower pressure
in the southern Caribbean is supporting fresh to strong NE winds
in the Windward Passage, offshore Colombia, and in the lee of Cuba
and Hispaniola. Moderate to fresh NE winds dominate elsewhere.
Seas are generally 4-6 ft throughout the basin, with the exception
of the Mona and Anegada Passages, where northerly swell
originating from the central Atlantic is increasing seas to 6-8
ft.

For the forecast, deepening low pressure across the central
Atlantic during the next few days will maintain NE winds across
much of the basin, and fresh to locally strong NE winds through
the Caribbean Passages, in the lees of the Greater Antilles, and
offshore Colombia through Thu night. Large NE swell across the
central Atlantic will move through the Caribbean Passages and
Tropical Atlantic waters into the weekend, with highest seas Thu
through Fri evening.

ATLANTIC OCEAN...

Please read the Special Features section above for details on a
storm-producing low pressure SE of Bermuda that has a potential
for tropical or subtropical development over the next 48 hours.

The powerful and strengthening low pressure in the central
subtropical Atlantic is dominating weather across much of the
basin. In the western Atlantic, winds increase to fresh
northerlies east of 70W and south of 25N, roughly aligning with
the area of 8 ft or greater seas. A warm front extends eastward
from the low to 28N42W. A recent scatterometer pass found a sharp
wind shift along this front with strong southerlies south of the
front and gale force easterlies north of the front. In the eastern
Atlantic, a cold front extends from 31N19W to 26N35W, where it
becomes stationary and extends to the aforementioned warm front.
Winds are moderate to fresh north of these boundaries with 8-10 ft
seas. South of the fronts, high pressure centered between the Cabo
Verde and Canary Islands dominates, with light to gentle winds and
6-8 ft seas.

For the forecast for areas W of 55W, by Thursday night or early
Friday, the large non-tropical area of low pressure located over
the central subtropical Atlantic will move northeastward over
cooler waters and interact with a mid-latitude trough, limiting
the chance for additional subtropical or tropical development of
the system. Regardless of development, winds should increase
tonight to storm force, and prevail at that magnitude into Wed
night. Gales will then continue in NE waters through at least Thu.
Overall, there is a medium chance of subtropical or tropical
development within the next 48 hours. Large long-period north to
northeast swell will impact the Atlantic waters and Caribbean
Passages between the southeastern Bahamas and the E Caribbean
producing high seas into the weekend, with large E swell reaching
the Florida offshore waters N of 26N early Fri through Sat.

$$
Flynn
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