[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211121
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Feb 21 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 0600 UTC surface analysis and satellite imagery through
1100 UTC.

...SPECIAL FEATURES...

Caribbean Sea Gale Warning: The pressure gradient between strong
high pressure north of the area and relatively lower pressure in
Colombia and in the far south-central Caribbean will continue to
maintain strong to near-gale force NE to E trade winds in the
south-central Caribbean offshore Colombia during the daytime
hours. These winds will pulse to gale-force during the late night
and early morning hours just offshore NW Colombia. An overnight
ASCAT satellite data pass nicely highlighted near gale to gale
force NE winds within about 120 nm offshore northwestern Colombia.
This weather pattern is expected to continue through the rest of
the week. Seas are forecast to build to near 14 ft with the
strongest winds.

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

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of Liberia near 07N11W
and continues southwestward to 05N16W, where latest scatterometer
data indicates that it transitions to the ITCZ and continues to
01N25W to 02N36W and to 01N50W. Scattered moderate to isolated
strong convection is noted within 120 nm S of the ITCZ between
25W-33W and within 120 nm N of the ITCZ between 33W-35W. Scattered
moderate convection is within 120 nm N of the ITCZ between
39W-42W and within 60 nm N of the ITCZ between 16W-19W. Similar
convection is N of the ITCZ from 03N to 06N between 46W-50W.

...GULF OF MEXICO...

The western extension of the Atlantic subtropical ridge reaches
westward to the eastern Gulf of Mexico. It is maintaining fairly
tranquil weather conditions across the basin. Moderate or lighter
anticyclonic winds are present along with seas of 3-5 ft per
latest buoy observations and altimeter data, with the exception of
slighter higher seas of 4-6 ft in the west-central Gulf section.

Areas of smoke and haze are in the southwestern and west-central
Gulf sections, while marine fog, some of which is dense in
patches and in areas, is along and just offshore the Gulf coastal
plains westward from Mobile, Alabama.

For the forecast, a 1019 mb high pressure center located near
25N86W will shift to well E of the Gulf by early Wed. Moderate to
fresh southerly winds will develop across the western half of the
Gulf today, then strengthen to strong to near gale-force tonight
and Wed over the NW and north-central Gulf, ahead of a frontal
system that will stall across Texas. High pressure and fresh
return flow is expected across most of the basin Thu, then over
the western section and also over the central section S of about
26N from Thu night through Fri night. Gentle to moderate E to SE
winds are expected across the basin Sat and Sat night as the
western extension of Atlantic high pressure will reach westward
along 30N.

...CARIBBEAN SEA...

Please read the Special Features section for details about the
ongoing Gale Warning.

The pressure gradient between the subtropical ridge centered north
of the Caribbean Sea and relatively lower pressure in NW South
America continues to support fresh to strong easterly breezes
across the central and eastern Caribbean Sea. Strong to near gale-
force winds are occurring in the south-central Caribbean and
winds to gale-force are offshore NW Colombia as described above
under the Special Features section. Outside of the Gale Warning
area, seas are 7-10 ft in the west central Caribbean from 11N to
15N W of 80W, 8-12 ft in the southwestern part of the sea due to
northeast swell, 9-13 ft S of 15N between 76W-80W and 5-8 ft
elsewhere except 3-5 ft N of 18N and W of 76W, where moderate
or lighter winds are present as noted in overnight ASCAT data
over that part of the basin.

Patches of moisture, in the form of low-level clouds, are
seen moving westward over the eastern Caribbean and elsewhere
S of about 18N. Isolated showers are possible with these clouds.

For the forecast, Atlantic high pressure ridge along 26N will
help sustain fresh to strong trade winds across the central
Caribbean through Wed, then become strong Wed night through Fri as
high pressure reorganizes NE of the Bahamas. Winds will pulse to
gale- force off the coast of Colombia at night through the period.
Fresh to strong NE to E winds will also occur in the Windward
Passage and lee of Cuba Wed through Fri night. Fresh to strong SE
winds will develop across the Gulf of Honduras tonight, then
spread to the Yucatan Channel through Thu night.

...ATLANTIC OCEAN...

High pressure over the Atlantic anchored by a 1022 mb high near
26N60W and a 1025 mb high well N of the area near the Azores
is the main feature controlling the weather pattern throughout.
It is inhibiting deep convective activity from developing. Fresh
to strong SW to W winds are occurring off NE Florida, especially
north of 29N and west of 78W as confirmed by an overnight ASCAT
pass. Seas over these waters are 6-9 ft. Moderate or lighter winds
and seas of 4-7 ft exist W of 60W. Farther east, a surface trough
extends from near 31N45W to 24N54W. No deep convection is being
produced by this feature. The aforementioned high pressure
supports gentle to moderate NE-E winds between 35W-60W. Seas over
these waters re 5-7 ft, except for a small pocket of 6-8 ft seas
from 25N to 27N between 41W-45W.

The pressure gradient between the 1025 mb high that is located
south of the Azores and relatively lower pressure in western
Africa is allowing for fresh to strong N-NE winds south of 22N and
east of 30W as seen in an overnight ASCAT pass over that part of
the Atlantic. Seas over these waters are 6-8 ft. Elsewhere,
moderate or lighter winds along with moderate seas prevail.

For the forecast W of 55W, an E to W ridge axis along 26N will
weaken through tonight, then reorganize NE of the Bahamas Wed.
Fresh to strong SW to W winds across the northern waters should
continue through early Wed as a frontal system sweeps eastward
across the NW Atlantic. The western end of that front will move
across the forecast NE waters Wed afternoon and night, and reach
along 22N late Thu. High pressure behind the front will act to
freshen NE to E trade winds south of 24N during this period.

$$
Aguirre
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