[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 211803
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sun May 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Excessive Rainfall in Panama, Colombia and Venezuela:
A pronounced upper-level trough extends southwestward from
Hispaniola across the Caribbean Sea into northern Colombia. It
has been interacting with the monsoon trough over Panama and
northwest Colombia to trigger widespread deep convection across
Panama, northern Colombia and northwestern Venezuela, and adjacent
Caribbean waters. This trend will continue through at least
Monday.

Please, refer to the latest forecasts from your local meteorological
agencies for more information.

Volcanic Ash from Popocatepetl:
Two large eruptions from Popocatepetl Volcano in Mexico near
19N98.6W have been observed overnight, sending volcanic ash as
high as 32000 ft into the atmosphere. Westerly winds at mid and
upper levels have transported the ash to near the Mexican coast
and nearby waters in the Gulf of Mexico, south of 22N and west of
94W. Some of this ash may be reaching the surface, which could
produce reduced visibilities for marine operations. Mariners
should exercise caution. If mariners encounter volcanic ash or
floating volcanic debris...you are encouraged to report this
observation to the National Hurricane Center by calling
001-305-229-4424.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is near 15W from Gambia
southward, and moving westward about 10 knots. Widely scattered
showers are seen from 07N to 09N between the Sierra Leone coast
and 17W. Much drier air at the lower level is limited shower
coverage.

Another eastern Atlantic tropical wave is near 33W from 12N
southward, and moving westward about 15 knots. Scattered moderate
convection is found from 05N to 08N between 31W and 35W.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic along the southern Senegal
coast and extends southwestward to near 08N19W. No significant
convection is present near this feature. An ITCZ continues
westward from 08N19W to 06N31W, then resumes from 05N36W to near
the French Guiana-Brazil border. Scattered moderate convection is
noted from 01N to 04N between 00W and 16W. Scattered moderate
convection is noted up to 90 nm along either side of the first
ITCZ segment west of 24W, and the entire second ITCZ segment.

...GULF OF MEXICO...

Refer the Special Features section above for information on
possible volcanic ash in the southwestern Gulf waters.

A weak cold front reaches west-southwestward from the Florida
Panhandle, passing just south of New Orleans to just north of
Brownsville, Texas. Scattered showers are occurring near and
north of this boundary. A surface trough is triggering similar
conditions over the central and eastern Bay of Campeche. Gentle to
moderate N to NE winds and seas of 1 to 3 ft are present for the
entire Gulf.

For the forecast, weak high pressure will dominate the Gulf of
Mexico through early week, inducing light to gentle winds and
slight seas. A diurnal trough will move offshore each night west
of the Yucatan Peninsula, causing moderate N to NE winds ahead of
it. A weak frontal trough will sink into the northern Gulf Wed
and move southward, and gradually produce gentle to moderate N to
NE winds across the entire basin. Popocatepetl Volcano in Mexico
near 19N98.6W has produced 2 large eruptions overnight, with ash
moving ENE away from the volcano. Ash has reached areas of the SW
Gulf of Mexico S of 22N and W of 94W. Visibility may be restricted
in this area due to volcanic ashfall through this evening.
Mariners should exercise caution.

...CARIBBEAN SEA...

Please refer to the SPECIAL FEATURES section on heavy rainfall
across Panama and parts of Colombia and Venezuela.

Convergent SE winds are producing scattered showers and isolated
thunderstorms near and south of Hispaniola. A modest surface
trough between eastern Cuba and Jamaica is triggering isolated
thunderstorms just southwest of the Windward Passage. Moderate E
to SE trades and seas at 4 to 6 ft are evident over the eastern
basin. Gentle to ENE to ESE trades with 2 to 4 ft seas are found
at the central basin. Light to gentle winds and seas of 1 to 3 ft
prevail for the rest of the basin.

For the forecast, a weak pressure gradient will sustain mainly
light to gentle winds in the western basin, and gentle to
moderate trades over the eastern Caribbean this week. Slight to
moderate seas will prevail. Convergent southeasterly winds feeding
toward a low pressure north of Hispaniola will continue to trigger
scattered showers and thunderstorms east of 69W in the Caribbean
early this week. A pronounced upper-level trough will sustain
similar conditions near the coast from Venezuela to Panama through
Tue.

...ATLANTIC OCEAN...

A surface trough reaches northeastward from the southeast Bahamas
through a 1011 mb low near 24N71W to southwest of Bermuda at
28N68W. Enhanced by a mid to upper-level trough in the vicinity,
scattered moderate convection is flaring up north of 20N between
64W and 72W. Fresh to locally strong SE to S winds and seas of 6
to 8 ft are present just east of this low from 21N to 26N between
66W and 70W. Otherwise, moderate to fresh NE to ESE trades with 6
to 7 ft seas are seen north of 16N between 35W and 73W. Farther
west, Light to gentle winds and seas of 3 to 5 ft in moderate
easterly swell exist north of 20N between 73W and the Florida-
Georgia coast. Near the Canary and Cabo Verde Islands, gentle to
moderate with locally fresh NNE to NE trades and 5 to 7 ft seas in
moderate northerly swell dominate north of 11N between the Africa
coast and 35W. To the west, gentle to moderate ENE to E trades
and seas at 5 to 6 ft are present from 05N to 16N between 35W and
the Lesser Antilles. Light to gentle winds with 4 to 6 ft seas in
a mix of northerly and southerly swells prevail for the remainder
of the Atlantic Basin.

For the forecast W of 55W, the Atlantic high pressure ridge is
centered on the Azores high along 32W and extends west-
southwestward to near 65W. The surface trough and associated low
near the Bahamas should move slowly north-northeastward through
Wed. Scattered showers and thunderstorms along with fresh S to SE
winds are expected near and east of the trough axis through Wed
night. Another frontal trough may move off the southeast U.S.
coast and impact northeast Florida waters Thu.

$$

Forecaster Chan
This weather bulletin was brought to you by:
www.nashvilleweather.net