[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301027
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Nov 30 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 0600 UTC surface analysis and satellite imagery through
1015 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Gale Warning: A cold front will enter the NW Gulf
this morning, followed by strong to near gale force N-NE winds.
Frequent gusts to gale force are expected in the NW Gulf through
this afternoon, more likely west of 94W. As a result, seas will
build to 8-10 ft in the NW Gulf this afternoon, then begin to
subside late tonight into Thu. Scattered showers and thunderstorms
are expected along and ahead of the front. Winds will diminish
on Thu as high pressure in the wake of the front shifts eastward.
Seas in the NW Gulf will subside to below 8 ft late on Thu.
For details on this Gale Warning, please read the latest High
Seas Forecast issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from the coast of Guinea-Bissau near
12N16W to 07N20W, where overnight scatterometer data indicates
that it transitions to the ITCZ to 05N30W to 03N40W and to 03N51W.
Scattered moderate convection is seen within 180 nm north of the
ITCZ between 38W-48W, and within 120 nm north of the ITCZ between
30W-34W.

...GULF OF MEXICO...

High pressure ridging associated to multiple high centers over
New England stretches southwestward to the central Gulf of Mexico.
The only moisture that is evident is that of the upper levels,
where high level clouds are streaming east-northeastward as seen
in satellite imagery. The gradient between the ridging and
relatively low pressures in the western Gulf is supporting
moderate to locally fresh southeast to south winds prevail in the
Gulf, except for light to gentle winds south of 20N in the western
and central Bay of Campeche, in the extreme northwest Gulf, where
gentle southwest winds are present. Seas range from 3-5 ft north
of 20N to lower values in the 1-3 ft range south of 20N.

For the forecast, high pressure over the area will shift eastward
through tonight in response to an upcoming strong cold front.
This front will enter the NW Gulf this morning followed by strong
to near gale force north to northeast winds. Frequent gusts to
gale force are expected in the NW Gulf today. The front will reach
from southeastern Louisiana to near Corpus Christi, Texas this
morning, and from near Tampa Bay, Florida to far northeastern
Mexico by early this evening. The front will stall and weaken late
tonight into Thu, then begin to dissipate through late Thu.
Strong high pressure behind the front will shift eastward through
the weekend allowing for winds to become easterly and moderate to
fresh in speeds across most of the basin. Scattered to numerous
showers and thunderstorms are expected along and ahead of the
front.

...CARIBBEAN SEA...

Scattered moderate to isolated strong convection is confined to
extreme southwestern Caribbean, mainly south of 13N and west of
79W. This is where the eastern segment of the E Pacific monsoon
trough is present. The rest of the basin is under fairly tranquil
weather conditions. High pressure north of the Caribbean
continues to support moderate to fresh trade winds in the eastern
and central Caribbean, including the Windward Passage, and in the
lee of Cuba. Similar winds are south of 16N and west of 80W.
Fresh to strong northeast to east winds have developed near the
coast of northwest Colombia between 74W-76W. Fresh, to at times,
strong northeast winds are in the Windward Passage and off the
coast of Hispaniola. Moderate or weaker winds are found elsewhere.
Seas are 4-6 ft in the eastern and central Caribbean, including
the Windward Passage. Seas are 3-5 ft in the remainder of the
Caribbean.

For the forecast, Atlantic high pressure will maintain moderate to
fresh trade winds across the central and eastern Caribbean Sea
through Thu afternoon. Winds will pulse to strong speeds tonight
south of Hispaniola and in the Windward Passage. Beginning late
Thu afternoon, fresh to strong northeast winds will develop in
the lee of Cuba, in the Windward Passage and continue south of
Hispaniola. These winds will spread a good distance to the
southwest over the western and central Caribbean areas through Sat
night as strengthening high pressure shifts offshore the mid-
Atlantic region. Long-period north swell propagating through the
Tropical N Atlantic waters will subside on Wed.

...ATLANTIC OCEAN...

A weak cold front is analyzed from 31N55W to 26N68W, where it
becomes a dissipating stationary front to the central Bahamas. No
deep convection is noted near the frontal boundary. Moderate to
locally fresh northeast to east winds are present behind the
front, along with seas of 3-7 ft. Similar winds are evident south
of 26N and west of 55W. Seas in these waters are 4-7 ft.

Farther east, an upper-level low is identified to be near 22N45W.
Ahead of the upper-level low, a surface trough extends from
31N46W to 26N51W and to 15N47W. The close proximity of these
systems is creating plenty of atmospheric instability that
is promoting a rather concentrated area of scattered moderate
convection that covers from 16N to 24N between 43W and the trough.
The rest of the tropical Atlantic is dominated by a broad
subtropical ridge that is centered in the northeast part of
the Atlantic. The pressure gradient between this ridge and lower
pressures in the deep tropics and in NW Africa is maintaining
moderate to fresh northeast to east winds south of a line from
the Canary Islands to the Leeward Islands. The exception was
captured by an overnight ASCAT satellite data pass that depicted
fresh to strong east winds from about 16N to 24N between 30W-37W.
Seas are 8-12 ft in these waters, with the highest seas occurring
in the area of strongest winds. Elsewhere, moderate or weaker
winds and moderate seas are noted under a weak pressure gradient.

For the forecast, the aforementioned weak cold front will become
stationary today and weaken before dissipating tonight. A
stronger cold front will move off the northeast Florida coast
early this evening, reach from near 31N63W to the NW Bahamas and
to South Florida Thu night, then become stationary near 25N by
late Fri afternoon as strong high pressure in the wake of the
front moves eastward. Scattered showers and thunderstorms will be
possible ahead of the front. On Thu, expect increasing winds and
building seas across most of the forecast waters W of 65W,
including the Bahamas and the Straits of Florida. Marine
conditions will continue to deteriorate across the waters W of 55W
Fri through the weekend, with seas building to around 17 ft east
of the Bahamas. Long- period north to northeast swell will impact
the waters between the southeastern Bahamas and Puerto Rico with
rough seas during the weekend leading to potentially hazardous
marine conditions.

$$
Aguirre
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