[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 230930
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Jan 23 2021

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

Caribbean Gale Warning: 1018 mb high pressure north of Puerto
Rico and low pressure over northern Colombia is resulting in a
tight pressure gradient in the south-central Caribbean. Winds are
pulsing to gale force during the overnight and early morning hours
which will continue through the next several days. Seas will build
to 11-12 ft around sunrise each day. Please read the latest NWS
High Seas Forecast issued by the National Hurricane Center at the
website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more
details.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Africa at the Cote
d'Ivoire and Liberia border near 04N08W to 04N27W. The ITCZ
extends from 04N27W to 05N50W. Scattered moderate and isolated
strong convection is noted from 05N-07N between 13W-17W, from
02N-04N between 17W-20W, from 00N-05N between 27W-33W, and from
04N-05N between 42W-49W. Scattered moderate convection is noted
from 01N-03N between 47W-51W near the coast of northern Brazil.

GULF OF MEXICO...

Patchy to areas of dense fog is noted across portions of the Gulf
coastal waters early this morning, with the potential for
visibilities to be reduced to 1 nm or less. This fog should
diminish by late morning. Otherwise, fair conditions are noted
across the basin.

A surface ridge extends from high pressure east of the southern
Bahamas across the upper Florida Keys and Florida Bay to the
north-central Gulf. A surface trough is analyzed in the western
Gulf from 29N93W to 26N96W to 21N97W. A stationary front extends
from northern Florida to across the northern coastal waters.
Earlier scatterometer data showed mainly light to gentle
anticyclonic winds under the ridging and gentle to moderate NE
winds behind the front, with N-NE moderate winds west of the
Yucatan Peninsula. Seas are mainly 3 ft or less across the basin
per recent buoy observations and altimeter data.

The stationary front will retreat northward as a warm front
through the remainder of the weekend. High pressure will rebuild
over the southeast U.S.A. with increasing southerly return flow
and building seas Sun into early next week. The ridge will weaken
late Mon as a weak cold front moves into the western Gulf,
stalling by early Tue. The front will then get reinforced and
progress eastward across the basin through the remainder of the
week.

CARIBBEAN SEA...

Refer to the Special Features section above for details on an
ongoing Gale Warning in the south-central Caribbean northwest of
the coast of Colombia.

Elsewhere, mainly gentle to moderate trades prevail, except
moderate to fresh in the central Caribbean. Seas are 3 ft or less
in the northwest Caribbean, and mainly 4-7 ft elsewhere. Isolated
tradewind showers are possible with no significant convection
noted across the basin, however deep convection is occurring over
portions of central to northwest Colombia and far eastern Panama.

Mainly moderate to fresh trades will prevail through the next
several days outside of the south-central Caribbean, pulsing to
fresh to strong over the Gulf of Honduras on Mon through Wed. N
swell will propagate into the Tropical North Atlantic waters from
Mon night through Thu. A cold front may approach the Yucatan
Channel from the northwest Thu night.

ATLANTIC OCEAN...

West of 55W, 1018 mb high pressure is noted east of the southern
Bahamas and Turks and Caicos near 23N66W with a ridge axis
extending west-northwest toward the upper Florida Keys. A cold
front extends from 32N58W to 28N70W to near Jacksonville, Florida.
Scattered showers are possible near the front with fair conditions
elsewhere. Fresh to strong SW winds are occurring north of 27N
and east of the front, with mainly gentle to moderate winds
elsewhere. A set of large northerly swell with seas of 7-11 ft
associated with the frontal system extend across the waters north
of 27N and east of 70W, with 3-6 ft seas noted elsewhere outside
of the Bahamas, except 4-7 ft east of 70W.

The cold front will reach along 26N by this evening, while a
reinforcing cold front merges with it along 25N by Sun morning.
The merged front will stall along 20N off the coast of the
Dominican Republic by Mon afternoon, and then dissipate on Tue.
A new cold front will move across the northern waters Tue night
shifting south while weakening through early Thu. Another cold
front may move off the southeast U.S.A coast by Thu afternoon
while parent low pressure rapidly intensifies north of the area
through the end of the week. Gale force winds and very large seas
are possible with this system, with storm force to near hurricane
force winds possible north of 32N.

East of 55W, a cold front extends from 1010 mb low pressure north
of the area near 37N39W through 32N40W to 26N44W to 20N59W.
Isolated to scattered showers are possible near the front, with
scattered moderate convection noted north of 27N between the front
and 37W. Fresh to strong SW winds are occurring north of 27N
within 120-180 nm ahead of the front, while northerly swell of
7-11 ft covers the waters north of 20N, except 11-14 ft north of
27N between 37W-50W. A 1027 mb high pressure area is centered
northwest of the Canary Islands near 32N20W with a ridge axis
reaching from the high west-southwest through 27N35W to 23N55W.
Moderate to fresh trades cover the waters south of 20N, with
gentle to moderate trades found near the ridge. Seas of 6-9 ft in
mainly fresh trade wind swell dominate the open waters of the
tropical Atlantic.

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