[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271740
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu May 27 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 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.

...TROPICAL WAVES...

A far eastern Atlantic tropical wave has its axis along 22W south
of 13N. It is moving westward at 15 to 20 kt. Scattered moderate
to isolated strong convection noted with 300 nm of either side
of  the wave from 01N to 06N. Another area of similar convection
is noted east of the wave from 02N to 05N between 05W to 16W.

Another tropical wave has its axis along 42W south of 12N. It is
moving westward at 15 to 20 kt. This wave is located under a
more  stable upper environment that is marked by subsidence and
dry sinking air found behind an upper-level trough. Scattered
moderate convection is west of the wave to the coast of Brazil
from 03N to 07N. ASCAT data from earlier today notes a surge of
fresh NE winds west of the wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough remains inland in Africa. The ITCZ is
identified  between the tropical waves from 05N26W to 04N39W.
Scattered moderate convection is within 100 nm north of the ITCZ
between 28W to 34W.

GULF OF MEXICO...

A ridge dominates the Gulf anchored by a 1022 mb surface high
pressure center over the western Atlantic. A local 1021 mb high
pressure center is south of the Florida Panhandle near 29N84W.
High  pressure and deep layer dry air apparent in water vapor
satellite imagery is keeping mainly fair weather conditions in
place. ASCAT data notes gentle to moderate E to SE winds are
across the basin. Seas are 1 to 2 ft in the NE Gulf and 3 to 5
ft in the SW Gulf.

For the forecast, gentle to moderate east to southeast winds are
expected through Sat night as weak high pressure off the NE
Florida coast extends westward to SE Texas and gradually
weakens. Fresh northeast to east winds will pulse nightly to
strong off the Yucatan Peninsula through Sat. A cold front is
expected to move across the northern Gulf on Sat night into Sun,
then stall across the northern Gulf Sun night. Expect moderate
north to northeast winds behind the front.

CARIBBEAN SEA...

The monsoon trough is analyzed over eastern Panama into the
eastern  Pacific. Scattered moderate convection associated with
the trough is in the SW Caribbean, south of 10N. Debris high
level cloudiness from this activity continues to stream eastward
over the SW Caribbean.

ASCAT data from this morning reveals fresh to strong NE winds
over  the central and south-central Caribbean, south of 16.5N.
Wave heights with these winds are in the 6 to 11 ft range.
Gentle to moderate trades are elsewhere across the basin with
seas ranging from 3 to 5 ft.

As for the forecast: Fresh to strong trades will prevail across
the central portions of the Caribbean through early today as high
pressure resides in the western Atlantic. Winds will diminish
significantly through early next week as the high collapses.
Fresh  winds are expected in the southern Gulf of Honduras and
the Windward Passage tonight.

ATLANTIC OCEAN

An upper-level low is vividly noted near 27N64W, with a surface
trough stretching from 30N63W to 23N65W.  A very moist and
unstable atmospheric environment around the upper-level low
along with upper diffluence is supporting scattered moderate
convection within 270 nm east of the surface trough. The GOES-16
geostationary lightning mapper reveals frequent lightning within
this convection.

Otherwise, high pressure is anchored in the western Atlantic
near  31N68W allowing for gentle return flow west of 65W with
seas of 3 to 5 ft. Farther east, another area of high pressure
is centered near 37N40W allowing for gentle to moderate NE to E
winds across the basin. Seas east of 50W range from 6 to 9 ft.

For the forecast, light winds will prevail north of 24N through
today as a weak trough along 65W interrupts the Atlantic ridge.
Moderate to locally fresh winds will continue across the Bahamas
and Greater Antilles through this morning. Winds will become
gentle to moderate later today through Sun as the Atlantic ridge
extends from the east-central Atlantic weakly WSW to Florida.
Fri night, moderate to fresh southerly winds will develop off
the NE Florida coast ahead of a cold front forecast to emerge
off the southeastern CONUS early Sun. A cold front will move
across northern Florida on Sun before stalling Sun night.

$$
Mora
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