[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231033
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Tue May 23 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
0930 UTC.

...SPECIAL FEATURES...

Gulf of Mexico Ashfall Advisory: The Popocatepetl Volcano in
Mexico continues in an active state of unrest. Ash from recent
large eruptions has moved E-NE as far as the Yucatan Peninsula.
Ash from more recent moderate eruptions is reaching as high as
30000 ft. Upper-level westerly winds are transporting the ash
across the adjacent SW Gulf of Mexico, S of 20N and west of 93W,
and is expected to reach 91W by morning. Mariners who encounter
volcanic ash or floating volcanic debris are encouraged to report
this observation to the National Hurricane Center, by calling
+1-305-229-4424.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 26W, south
of 12N. It is moving west at 10 kt. Scattered moderate to strong
convection is observed from 05N to 09N and between 21W and 28W.

Another eastern Atlantic tropical wave has its axis along 42W,
south of 10N. It is moving westward at 10 kt. Scattered moderate
to strong convection is present from 04N to 09.5N between 39W and
46W.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Guinea-Bissau near 11N15W and continues to 08N20W. The ITCZ
extends from 08N20W to 07.5N25W, then resumes from 07N27W to
06N40W, and then resumes again from 06N43W to the coast of Guyana
at 07.5N59W. Scattered moderate isolated strong convection is
seen from 01.5N to 07N between 07W and 17W. Outside of convection
described with the tropical waves, scattered moderate to strong
convection is noted within 120 nm N and 60 nm S of the ITCZ
between 28W and 47W.

GULF OF MEXICO...

Please read the Special Features section for information on the
Ashfall Advisory for the SW Gulf of Mexico.

An outflow boundary has moved west-southwestward across much of
the NE Gulf overnight, and has recently reached from Lake
Pontchartrain to just north of Tampa Bay. The passage of this
boundary has triggered scattered moderate convection that lingers
from 27N to 29N between 85W and 89W. The rest of the basin is
dominated by a weak high pressure system centered over the NW
Gulf. Surface observations and a recent scatterometer satellite
pass show light to gentle anticyclonic winds prevailing over most
of the Gulf, except for localized fresh winds off the Big Bend
region of Florida, behind the outflow boundary, and in the
eastern Bay of Campeche. Seas are 1-3 ft across the Gulf waters.

For the forecast, weak high pressure will generally dominate the basin
through the week, yielding light to gentle winds and slight seas.
A modest cold front will move S through the eastern Gulf
late Wed through Thu, followed by moderate to locally fresh N to
NE winds E of 90W through Sat morning. Popocatepetl Volcano in
Mexico near 19N99W has been active since Sun and continues to
erupt this morning. Ash has moved E to NE away from the volcano
and over the Bay of Campeche, S of 22N and W of 90W. Visibility
may be restricted in this area due to volcanic ashfall through
tonight. Mariners should exercise caution.

CARIBBEAN SEA...

An upper level trough extends from the western Atlantic S-SE
across the Mona Passage into the NE Caribbean, and is shifting
slowly eastward. This feature is supporting scatted showers and
isolated thunderstorms from eastern Puerto Rico, east and
southeast across the eastern Caribbean, the Lesser Antilles, and
to the Atlantic waters W of 5W. The rest of the Caribbean Sea
experiences generally dry conditions. The weak pressure regime
maintains gentle to moderate easterly trade winds in the central
and eastern Caribbean, while light to gentle easterly breezes are
found in the remainder of the basin. Seas are slight to moderate
across the Caribbean.

For the forecast, elongated low pressure extending from the SE
Bahamas to near 30N70W will lift N-NE and exit the region early
Wed. Low pressure is then expected to develop over central Florida
Wed night and move slowly NE through Sat. This pattern will
maintain a weak pressure gradient across the central and western
Caribbean through Sat, supporting light to gentle winds. Over the
E Caribbean, the Azores High ridge will support gentle to moderate
SE trade winds through the forecast period. Expect scattered
showers and thunderstorms across the waters between 65W and 55W
through Tue night.

ATLANTIC OCEAN...

A surface trough extends from low pressure near Bermuda through
1008 mb low pressure near 25.5N71.5W to offshore of Haiti near 21N71W.
An upper level trough across the western Atlantic W of 70W and
extends S-Se through the MOna Passage. This deep layered feature
is supporting scattered moderate to isolated strong convection
to the east of the surface trough to west of 63W, and north of
22N. Overnight scatterometer satellite data depicted fresh
northerly winds within 180 nm of the low in the W and NW
quadrants. Gentle to moderate winds, in cyclonic fashion, are
noted elsewhere within 360 nm of the low and trough. Seas of 6-9
ft are present over the waters north of 22N and east of the
Bahamas to 60W. Farther west, a weak stationary front is along
about 31N and reaches NE Florida, where and a few thunderstorms
are seen near the boundary.

The remainder of the tropical Atlantic is dominated by an
extensive subtropical ridge positioned north of the Azores. The
pressure gradient is supporting moderate to fresh easterly winds
over most of the central and eastern Atlantic waters. Localized
strong winds are evident in the areas of the ITCZ where strong
convection resides. Moderate seas of 6 to 8 ft are prevalent in
the central and eastern Atlantic. Elsewhere in the basin, moderate
or weaker winds and moderate seas prevail.

For the forecast W of 55W, the elongated low pressure will move
N-NE and reach near 30N70W early Wed, when it will interact with a
weak cold front approaching from the NW, then move NE and exit
the region Wed night. Fresh to strong SE winds, rough seas, with
scattered showers and tstms will prevail E of the low and trough
through Wed. New low pressure is forecast to develop over central
Florida late Wed, move N-NE off the peninsula Thu, and across the
far NW waters through Sat. The pressure gradient between high
pressure over the eastern U.S. and the low will support fresh to
locally strong NE winds and large NE swell across the NE Florida
offshore waters beginning Thu night through Sat. Gale-force NE
winds are possible late Fri across these waters.

$$
Stripling
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