[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 052329
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Tue Dec 06 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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

Atlantic Storm Warning: A deepening broad 1002 mb low is
centered near 25N57W. A trough extends from the low to just
north of the British Virgin Islands. A stationary front extends
from the low northeastward to 27N55W and eastward to 27N50W to
26N43W, and northeastward from there to low pressure near 29N32W
1007 mb. An ASCAT data pass from this afternoon depicted gale-
force northeast to east winds within about 300 nm NE of the 1002
mb low. Seas with these winds are in the 14-18 ft range. The low
is embedded also within a broad upper-level trough that is
clearly evident in water vapor imagery. Latest satellite imagery
shows quite an extensive area of numerous moderate convection
that covers the area from 20N to 31N and between 42W-58W. This
area of convection is gradually sliding east- northeastward. The
area of gale-force winds is forecast to expand to north of 27N
and between 47W-60W by early on Tue, with seas building to 15-22
ft. sustained winds in the range of 40-50 kts are forecast to
begin late Tue night into early Wed morning. Seas are forecast to
significantly build to a range of 24-28 ft by this time. Marine
conditions will become substantially hazardous in this region as
the low intensifies. Mariners are urged to activate a plan of
avoidance to avoid these hazardous conditions. Please read the
latest High Seas Forecast issued by the National Hurricane Center
at the website:
http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis approaches the coast of Sierra Leone,
but remains inland over Africa. Latest scatterometer data
indicates that the ITCZ begins just offshore the coast of Sierra
Leone near 07N12W and extends to 06N24W, and resumes to the west
of a trough near 06N27W to 07N36W to 06N43W and to 06N50W.
Scattered moderate to isolated strong convection is noted within
180 nm north of the ITCZ between 19W-24W. Scattered moderate
convection is within 240 nm south of the ITCZ between 18W-22W,
within 60 nm south of the ITCZ between 31W-35W and within 60 nm
north of the ITCZ between 36W-45W.

GULF OF MEXICO...

The 18 UTC analysis has a 1019 mb high center over the far
eastern Gulf near 27N83W. A 1019 mb high center is just inland
the coast of Mexico near Jalapa. Generally, weak high pressure is
present over the area. The associated gradient is allowing for
gentle to moderate southeast to south winds over the area, except
in the southeastern part of the Gulf, including the Straits of
Florida, where winds are from the east, gentle to moderate in
speeds. Seas are 3-5 ft throughout, with the exceptions of the
north-central, NE and southeastern sections, where seas are
slightly lower in the 2-4 ft range per latest buoy observations
and altimeter data passes. The basin remains void of significant
convection, with the exception of a few thunderstorms over the
central Bay of Campeche. This activity will most likely dissipate
in a few hours. Broken areas of dense fog are over the coastal
waters of southeastern Louisiana, Alabama and northwest Florida.

For the forecast, high pressure over the area will remain in
place through Fri. Moderate to fresh return flow will continue
west of 92W through Wed.

CARIBBEAN SEA...

The pressure gradient between high pressure over the Gulf of
Mexico and lower pressures western Caribbean and over Colombia
is allowing for fresh to strong north to northeast winds south
of Cuba and Hispaniola, including the Windward and Mona Passages,
where seas are 6-8 ft. Elsewhere, latest satellite ASCAT data
passes indicate moderate trade winds over the eastern Caribbean
where seas are 3-5 ft, and moderate to fresh trade winds are over
the western and northwestern Caribbean Sea, where seas are 4-6
ft. Moderate to fresh trade northeast to east trade winds are
also noted within 60 nm of the coast of Colombia, also with seas
of 4-6 ft.

For the forecast, deepening low pressure across the central
Atlantic during the next few days will initiate northeast
winds across much of the basin, and fresh to locally strong
north to northeast winds through the Caribbean Passages and in
the lee of Cuba through Thu. Large northeast swell in the
central Atlantic will move through the Caribbean Passages and
Tropical Atlantic waters through the end of the week.

ATLANTIC OCEAN...

Please read the Special Features section above for information
about ongoing gale winds that are forecast to increase to storm
force in association with deepening broad low pressure that is
centered about 530 nm southeast of Bermuda.

The dominate feature in the Atlantic basin is the Special
Features 1002 mb deepening low pressure system that is centered
near 25N57W. A surface trough extends from this system
southwestward to just north of the British Virgin Islands.
Isolated showers are along and the trough. These showers are
moving in a general north to south motion per satellite imagery
detected motion, and as seen on the San Juan radar display
imagery. Moderate to fresh northwest to north winds are west
of the trough to near 62W. Similar winds are within 180 nm east
of the trough from 22N to 24N. Moderate to fresh north winds are
elsewhere west of the low and trough to near 73W. Light to
gentle north to northeast winds are west of 73W, except for
northeast to east south of 25N and west of the Bahamas, including
the Straits of Florida. Large seas are in the range of 6-9 ft
primarily due to a long-period northeast swell elsewhere west of
the low and trough to the Bahamas and to 78W north of Bahamas.
Seas are 5-7 ft west of the Bahamas and 78W, except 3-5 ft in
the Straits of Florida. The remainder of the central and eastern
Atlantic is dominated by high pressure, with 1016 mb high center
near 23N22W. The associated gradient is allowing for gentle to
moderate anticyclonic winds over these sections of the discussion
area.

For the forecast W of 55W, fresh to strong north to northeast
winds will continue east 70W through late Tue associated with
the 1002 mb low pressure system near 25N57W. The low will move
in a small cyclonic loop and deepen through Wed, before moving
northeast to east, then exit the region to the northeast on Fri.
Near gale force winds are occurring across the far northeastern
waters will increase to gale-force tonight, then briefly to storm
force by Wed morning. Winds will then diminish slightly with
gale- force winds continuing Wed afternoon through Thu. Large
long- period north to northeast swell will continue to impact
the Atlantic waters and Caribbean Passages between the
southeastern Bahamas and the eastern Caribbean, with high seas
throughout the rest of the week. Large east swell is forecast to
reach the Florida offshore waters north of 26N from early Fri
through Sat.

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