[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231724
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Feb 23 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...

Caribbean Sea Gale Warning: A high pressure ridge between the
Bahamas and Bermuda combined with the Colombian low will help
maintain fresh to strong trades across the central Caribbean for
the next several days. Winds will pulse to gale-force off the
coast of Colombia during the evening and early morning hours
through Sat night. The coverage area of the fresh to strong trades
is expected to diminish beginning late Sat night as the high
pressure located N of area weakens. Seas will peak near 14 ft with
the strongest winds.

Please read the latest High Seas Forecast at
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic through the coast of
Sierra Leone near 07N12W and continues southwestward to 03N20W.
The ITCZ extends from 03N20W to the equator at 30W, then to
01N50W. Clusters of moderate to isolated strong convection are
noted from the equator to 03N between 25W and 38W. Similar
convection is also seen from 00N to 04.5N between 46W and 51W.

GULF OF MEXICO...

A 1026 mb high pressure system positioned SE of Bermuda near
31N61W has a ridge that extends westward into the Gulf of Mexico.
Some cloudiness, with possible showers, is noted over the western
Gulf while dry air is evident over the rest of the basin. Fresh
to locally strong anticyclonic flow dominates most of the Gulf
waters. Seas of 6-8 ft due to SE to S swell are over the NW Gulf
per latest altimeter passes, while seas of 5-7 ft are elsewhere
are over the Gulf with the exception of lower seas of 3-5 ft in
the central Bay of Campeche and in the offshore waters of W
Florida.

Dense fog advisories were in effect along the coasts of Texas and
Louisiana to around 10 am. Some of the buoys and platforms in the
NW Gulf were also reporting light fog this morning. The return
moist southerly flow across the Gulf of Mexico will continue to
favor the development of fog during the overnight and morning
hours along the northern Gulf states. Mariners should take
precaution navigating these waters as visibility may decrease
below 1 nm. Also, areas of smoke and haze due to agricultural
fires in southeastern Mexico are confined to the the far
southwestern Gulf.

For the forecast, a high pressure ridge between the Bahamas and
Bermuda interacting with an expansive area of deep low pressure
over the central U.S. is allowing for fresh to locally strong SE
to S winds over most of the Gulf. As the low pressure continues to
shift northeastward, these winds should diminish by this evening.
However, a diurnal trough developing over the Yucatan Peninsula
during the day will induce fresh to strong E to SE winds over the
SW Gulf nightly for the next several days. Elsewhere, moderate or
weaker E to SE winds should prevail through Mon night. Looking
ahead, a weak cold front may emerge off of the Texas and Louisiana
coast on Mon.

CARIBBEAN SEA...

Please read the Special Features section for information on the
ongoing Gale Warning for the south-central Caribbean off the
coast of Colombia.

Fresh to strong easterly trade winds are prevalent across most of
the Caribbean Sea waters. The strongest winds are found in the
south-central Caribbean, S of Hispaniola and in the Gulf of
Honduras. Seas are 8 to 11 ft in the south-central Caribbean, 8 to
9 ft in the Gulf of Honduras, and 4 to 7 ft elsewhere, except in
the lee of Cuba where seas are in the 1 to 3 ft range.

Low topped trade wind showers are noted moving across the basin.
They are more concentrated over the Lesser Antilles and the
eastern Caribbean. The San Juan Doppler Radar shows these showers
moving across the US/UK Virgin Islands and Puerto Rico.

For the forecast, a high pressure ridge between the Bahamas and
Bermuda will help maintain fresh to strong trades across the
central Caribbean for the next several days. Winds will pulse to
gale-force off the coast of Colombia evening and early morning
hours through Sat night. The coverage area of the fresh to strong
trades is expected to diminish beginning late Sat night as the
high pressure weakens. Fresh to strong NE to E winds will also
occur in the Windward Passage and lee of Cuba through Sun night.
Strong to near gale E to SE winds in the Gulf of Honduras will
continue the next several days. Looking ahead, large long-period N
swell may begin impacting the tropical N Atlantic zones starting
Sun night.

ATLANTIC OCEAN...

Since yesterday, satellite imagery is showing an unusual outbreak
of African dust just S of the Cabo Verde Islands that is now
reaching near 50W. Saharan Air Layer (SAL) activity usually ramps
up in mid-June, peaks from late June to mid-August, and begins to
rapidly subside after mid- August.

A cold front extends from near 31N39W to 26N50W to 25N63W. Satellite
imagery shows increasing showers and thunderstorms ahead of the
front to about 36W and N of 24N. Recent scatterometer data indicate
the wind shift associated with the front, and suggest that a
shearline should be place on the next surface analysis W of 50W.
The remainder of the Atlantic is dominated by a rather expansive
areas of high pressure. As previously mentioned, a 1026 mb high
pressure center is positioned SE of Bermuda and a modest gradient
supports moderate to locally fresh NE to E winds N of Hispaniola
to about 22N based on recent satellite derived wind data. Seas
over these waters are 4 to 7 ft. Moderate southerly winds are
located off NE Florida, along with seas of 3-4 ft.

Another high pressure center of 1022 mb is located near 28N30W.
The pressure gradient between this system and lower pressures over
W Africa supports an area of fresh to strong N to NE winds between
the coasts of Mauritania and Senegal and the Cabo Verde Islands
according to an ASCAT pass. Seas are in the 6 to 8 ft range within
these winds. Elsewhere in the basin, moderate or lighter winds
and moderate seas prevail.

For the forecast W of 55W, a high pressure ridge between the Bahamas
and Bermuda will help maintain fresh to strong trades north of
Hispaniola and gentle to moderate winds elsewhere through Sat
night. The W end of a weak cold front moving southeastward across
the NE forecast waters will dissipate by Fri morning. A stronger
cold front will move across the N forecast waters Fri night, extend
from near 31N55W to 28N65W to 31N78W Sat morning, and weaken as
it reaches from near 24N55W to 24N65W Sun morning. Strong NW to N
winds are likely on Sat across the NE waters behind the front,
with large N swell propagating southward east of 65W though Mon
night. Looking ahead, another cold front should arrive over the NE
waters on Sun, causing strong breeze to near gale conditions on
both sides of the front north of 27N through Mon night. NE swell
producing large seas is expected behind this front.

$$
GR
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