[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211053
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Fri Apr 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
1030 UTC.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends from the coast of Guinea near 12N15W
southwestward to 03N21W, where latest scatterometer data indicates
that it transitions to the ITCZ and continues from 01S25W and to
01S32W, where it briefly pauses east of a trough that extends
from 06N32W to 01S34W. It resumes west of the trough at 01S36W and
continues to near the coast of Brazil at 02S42W. Increasing
0numerous moderate to strong convection has moved offshore the
coast of Africa from 04N to 10N between the coast and 17W.
Scattered moderate to isolated strong convection is seen from 01S
to 02N between 26W-30W. Scattered moderate convection is south of
the trough from the Equator to 03N and between 12W-17W.

GULF OF MEXICO...

High pressure stretches from the southeastern U.S. southwestward
to the north-central Gulf. The associated gradient is allowing for
generally moderate to fresh return flow over most of the basin,
with locally strong east winds west of the Yucatan Peninsula.
Seas are 4-6 ft over the NW Gulf, the west-central Gulf and the
eastern Bay of Campeche and 3-5 ft elsewhere per latest buoy
observations. Visibility may be reduced at times over the SW Gulf
and Bay of Campeche due to smoke and haze from agricultural fires
over southern Mexico and Central America. A line of numerous
moderate to strong thunderstorms is quickly moving into the far NW
Gulf. This activity contains frequent lightning, very heavy rain
and strong gusty winds.

For the forecast, the aforementioned high pressure along the
southeastern U.S. seaboard will continue to support moderate to
fresh southeast to south return flow over the Gulf of Mexico
today. Fresh to strong east winds will develop along and just
offshore the northern Yucatan Peninsula at night Sun and Tue. A
cold front will move over the NW Gulf tonight into early Sat.
Moderate to fresh N to NE winds will follow in behind the front on
Sat. The dissipating front will extend from southwestern Florida
to near the Texas- Mexico border by early Sun. Fresh to strong E
to SE to E winds are expected on Sun through Mon over most of the
western and central Gulf. Agricultural fires mainly over southern
Mexico and Central America may result in smoke and haze over the
the SW Gulf and the Bay Campeche through at least Sat. Mariners
may experience reduced visibility over these waters.

CARIBBEAN SEA...

A surface trough that extends along 75W from eastern Cuba to the
central Bahamas is disrupting the subtropical ridge north of the
area. As a result, only light to gentle trade winds exist west
of 79W, with the exception of moderate to fresh east to southeast
winds near the coast of Honduras. The gradient is allowing for
moderate to fresh northeast to east winds across the Caribbean
east of 80W. Combined seas are 5-7 ft east of 80W and lower seas
of 2 to 4 ft west of 80W.

For the forecast, high pressure north of the area will weaken
through tonight. This will allow for fresh northeast to east
trade winds over the south-central Caribbean to become light and
variable winds and for fresh east trade winds over the Gulf of
Honduras to diminish slightly. Elsewhere, rather quiet marine
conditions can be expected through early next week.

ATLANTIC OCEAN...

A mid to upper-level low is starting to take shape near 30N74W as
noted in water vapor imagery. A trough extends from the low
southward to the central Bahamas. At the surface, a trough is
analyzed along 76W from eastern Cuba northward to near 28N.
Recent satellite imagery shows increasing shower and thunderstorm
activity present to the east of the upper-level low and trough
from 22N to 30N and between 63W-74W. This activity is under a
region of upper-level diffluence that is helping to sustain it.
The gradient between the surface trough and the subtropical ridge
north of the area is generally supporting moderate to fresh east
winds and 4-6 ft seas from about 26N to 31N and west of 65W.
Strong winds are likely in and near the shower and thunderstorm
activity as were suggested in an overnight ASCAT pass. Seas over
this part of the area are in the 4-6 ft range. Farther east,
the ridging associated to high pressure of 1020 mb located
near 26N50W is supporting moderate to fresh trade winds and seas
of 5-7 ft south of 15N, and light to gentle winds and seas of 4-6
ft due to a long-period north to northeast swell. The tail-end of
a cold front is analyzed from near 31N53W to 28N59W. Isolated
showers and thunderstorms are ahead of it to near 48W and from 31N
to 32N.

Broad high pressure ridging is present over the eastern part of
the discussion maintaining rather tranquil conditions there.

For the forecast west of 55W, weak low pressure is forecast to
develop along a trough by tonight east of the Bahamas and drift
southward through Sun. A tight gradient will develop between high
pressure to the north and the low. This will increase the trade
winds to fresh to strong speeds between Bermuda and the Bahamas
from tonight through late Sat night, and along with seas building
to about 8 ft. Seas will subside late Sat night. A weak cold front
is expected to move off the coast of northeast Florida Sat night,
then dissipate north of the Bahamas by Mon. Moderate north swell
is forecast to impact the northern waters east of 60W beginning
on Sat.

$$
Aguirre
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