[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221728
TWDAT

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

...SPECIAL FEATURES...

Gulf of Mexico Storm Warning: A strong cold front is expected to
move off the Texas coast later this afternoon. The front will
bring widespread gale force NW winds and rough to very rough seas
across most of the basin tonight through Fri. Minimal storm-force
winds are expected Fri afternoon near Veracruz. Gale-force winds
will come to an end by Fri night for most of the basin. Gale-force
winds are expected to continue near Veracruz through Fri night
and possibly Sat and Sun. The 12 ft seas will spread across nearly
all of the Gulf west of 85W with peak seas approaching 20 ft.
Conditions will slowly improve later this weekend and into early
next week. A blast of arctic air will also follow the front
bringing to south Florida the coldest temperatures so far this
season during the upcoming holiday weekend.

SW N Atlantic Gale Warning: A strong cold front will emerge from
the SE United States coast tonight into early Fri morning. W to
NW gales should occur west of the frontal boundary Fri morning
through Fri afternoon north of 30N west of 74W. Seas may reach 15
ft on Fri. By Fri night, the gales will move north of the forecast
waters. Strong winds will slowly diminish on Sat and the seas
will gradually subside by Sun.

Please read the latest High Seas Forecast issued by the National
Hurricane Center at http://www.nhc.noaa.gov/text/MIAHSFAT2.shtml
for more details on the Gale and Storm Warnings.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic Ocean through the coast of
Sierra Leone near 08N13W and continues to 07N20W. The ITCZ extends
from 07N20W to 03N30W to the coast of Brazil near 02N50W.
Isolated to scattered moderate convection is observed from 02N to
07N between 24W and 32W, and within about 120 nm N of the ITCZ W
of 42W.

GULF OF MEXICO...

Please read the Special Features section above for information
on the Storm warning. This front will bring dangerous weather
conditions across the Gulf region tonight through Fri.

A weak pressure gradient dominates the basin with a weak 1015 mb
low pressure located near 27.5N88W. A trough is associated with
this low and extends from 29N88W to 24N91W. A few showers and
thunderstorms are noted ahead of the trough, particularly from 25N
to 27.5N between 85W and 88W. Abundant multilayer clouds with
possible showers are noted across much of the Gulf waters. As of
1500 UTC, another 1015 mb low pressure is added to the surface
map near the coast of Texas, and just E of Corpus Christi. A
recent scatterometer pass confirmed the presence of this low that
is producing gentle to moderate southerly winds over the NW Gulf.
Elsewhere, light to gentle winds prevail. Seas are 2-3 ft in the
eastern Gulf and 4-6 ft elsewhere across the basin.

For the forecast, a Storm Warning has been issued for the Gulf of
Mexico. Please, see the Special Features section for details.

CARIBBEAN SEA...

The most recent satellite derived wind data provide observations
of fresh to strong trade winds over the south-central Caribbean
where seas are in the 8 to 10 ft range. These winds are the
result of the pressure gradient between high pressure N of the
basin and the Colombian/Panamanian low. Elsewhere across the E and
central Caribbean, moderate to fresh trades prevail with seas of
4 to 6 ft. Over the NW Caribbean, light to gentle winds and seas
of 2-4 ft are noted, except 1 to 2 ft in the lee of Cuba. Shallow
moisture embedded in the trade wind flow is moving across the
region producing isolated to scattered passing showers.

For the forecast, surface ridging north of the region will support
pulsing fresh to strong NE to E tradewinds across the central and
SW Caribbean through early next week. Moderate to fresh winds
will prevail in the E Caribbean with gentle to moderate winds in
the NW Caribbean through the weekend. Moderate long-period N to
NE swell will persist over the tropical Atlantic waters through
early next week. A cold front will move into the NW Caribbean by
late Fri into early Sat. The front will reach from central Cuba to
the northern Yucatan by Sat night, stall from eastern Cuba to the
Gulf of Honduras on Sun night and linger in this area through
early next week. Fresh to strong winds and rough seas will follow
the front.

ATLANTIC OCEAN...

A Gale Warning is in effect for the SW N Atlantic. Please read
the Special Features section for details.

The low pressure area previously located off NE Florida has moved
N of the forecast area, and now is along the coast of South Carolina
near 32.5N80W. A cold front extends from the low center to near
29N74W where it becomes stationary reaching south-central Florida.
Only a few showers are near the frontal boundary. Fresh to locally
strong westerly winds are noted ahead of the front N of 29N to
about 77W per a recent ASCAT pass. A 1016 mb low pressure is
analyzed E of the Bahamas near 26N72W with a surface trough
extending along 24N71W to the SE Bahamas. A well defined swirl of
low clouds is noted on visible satellite pictures associated with
this low. The most recent scatterometer data indicated fresh to
strong easterly winds between the low and a ridge across the
waters between 60W and 70W. Seas in this area are 6 to 8 ft with
higher seas of 8 to 11 ft across the northern semicircle of the
low center. Farther east, a cold front enters the forecast region
near 31N37W and extends SW to near 26N46W. Then, a stationary
front stretches from this point to near 23N66W. Multilayer clouds
with embedded showers are related to the frontal boundary.
Moderate to fresh NE-E winds are found north of the front, along
with seas of 8-14 ft in N swell. The highest seas are occurring
north of 26N between 40W and 52W.

The remainder of the Atlantic forecast waters is dominated by a
ridge with a 103o mb high pressure system near the coast of
Portugal. The pressure gradient between the ridge and lower
pressures in the vicinity of the ITCZ support moderate to fresh
trade winds across the tropical Atlantic, especially south of 20N.
Seas are 7-9 ft in these waters. Moderate or weaker winds and
slight to moderate seas prevail elsewhere.

For the forecast west of 55W, refer to the Special Features
section for details on a Gale Warning associated with the next
cold front moving off NE Florida.

$$
GR
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