[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 082315
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Fri Jun 9 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 1800 UTC surface analysis and satellite imagery through
2300 UTC.

...SPECIAL FEATURES...

Excessive Rainfall possible for Cuba and Bahamas:
Moist southerly mid-level flow combined with enhanced rising air
motion due to a strong upper-level jet positioned just northwest
of this area will maintain the potential for heavy rain and
strong thunderstorms. Over 4 inches (100 mm) of rain was observed
over isolated areas in eastern Cuba in the last 24 hours, and
additional rain is forecast over the next 2 or 3 days. The
heaviest rainfall is expected to occur through Sat afternoon
across portions of eastern and central Cuba and the central
Bahamas. These rains could cause flooding, especially over
mountainous areas in eastern and central Cuba. Please see the
latest forecast from your national meteorological service for
more information.

...TROPICAL WAVES...

Three tropical waves are analyzed between the W coast of Africa
and the Lesser Antilles.

A new tropical wave is added to the 1800 UTC surface map along
12W from 12N southward based on the Tropical Wave Diagnostic and
the Hovmoller Diagram, that shows the westward propagation of
the wave. Scattered moderate convection is near the southern end
of the wave axis.

Another tropical wave is along 35W, from 13N southward, moving
westward at 10 to 15 knots. Scattered moderate and isolated
strong convection is noted ahead of the wave axis from 04N to
09N between 35W and 40W.

A third tropical wave is along 56W, from 12N to inland Suriname,
moving westward at 10 to 15 knots. Scattered moderate convection
is seen where the wave meets the ITCZ from 07N to 09N between
54W and 59N. Clusters of moderate to isolated strong convection
are inland on either side on the wave affecting parts of French
Guiana, Suriname and Guyana.

The axis of a Caribbean Sea tropical wave is near 73W, from 13N
southward, moving westward at 10 to 15 knots. The wave is
enhancing scattered to numerous moderate to strong convection
over northern Colombia and regional waters.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coast of The Gambia near
13N17W the continues SW to near 08N19W. The ITCZ extends from
08N19W to 07N40W to 09N60W. Outside of the convection associated
with the tropical waves, scattered moderate to isolated strong
convection is noted from 05N to 08N between 20W and 26W.

...GULF OF MEXICO...

A weak pressure pattern continues to dominate the Gulf waters
supporting mainly light to gentle winds and slight seas. A 1012
mb high pressure is over the western Gulf near 25N95W while a
surface trough extends from northern Florida to near 25N86W.
Scattered showers and thunderstorms are noted over the north
Gulf, particularly N of 27N between 86W and 94W. A mid- upper
level trough, that now extends over the eastern Gulf, is
enhancing convection over Florida and western Cuba.

For the forecast, the weak pressure gradient will generally
prevail across the basin through the end of the week, with
mainly gentle to moderate winds. Moderate to locally fresh
return flow will develop across the western Gulf over the
upcoming weekend.

...CARIBBEAN SEA...

See Special Feature above for heavy rainfall to affect Cuba
through Sat afternoon.

Convection has flared-up over western Cuba this afternoon ahead
of a mid-upper level trough located over the eastern Gulf of
Mexico. Scattered to numerous showers and thunderstorms continue
to affect eastern Cuba and Jamaica. Similar convective activity
is noted over parts of Central America, more concentrated over
Panama and Costa Rica.

The pressure gradient between high pressure building northeast
of the area and the Colombian/Panamanian low is supporting
mainly moderate to fresh E to SE winds across most of the east
and central Caribbean with seas of 4-7 ft based on altimeter
data. Light to gentle winds and seas of 2-4 ft are noted over the
NW and SW Caribbean.

For the forecast, high pressure over the central Atlantic will
maintain fresh to strong easterly trade winds in the eastern and
central Caribbean through Fri. The ridge will weaken Fri night
through the weekend, with winds and seas across the basin diminishing
modestly. A return to a more typical easterly trade wind regime
is expected early next week, with locally strong trades in the
south-central Caribbean and Gulf of Honduras.

...ATLANTIC OCEAN...

Please see Special Features above for heavy rainfall to affect
the Bahamas through Sat afternoon.

High pressure of 1021 mb located over the central Atlantic near
26N55W extends a ridge westward across the Greater Antilles, the
Bahamas and the western Atlantic. Multilayer clouds, with
embedded showers and thunderstorms dominate most of the waters W
of 70W, and N of 22N between 60W-70W. This cloudiness is associated
with strong upper-level winds. Moderate to locally fresh southerly
winds are noted on the western periphery of the ridge, with seas
of 4-6 ft E of the Bahamas. A weakening cold front enters the
forecast waters near 31N37W and extends SW to near 26N44W. A
weak low pressure of 1015 mb is still noted near 23N29W. A weak
pressure gradient dominates the eastern Atlantic. Light to gentle
winds are blowing across the Atlantic N of 12N and E of 50W with
seas generally in the 2-4 ft range. Moderate to locally fresh
trades are E of the Lesser Antilles to 50W with seas of 4-5 ft.

For the forecast west of 55W, a tightening pressure gradient
between the high pressure system over the central Atlantic and
lower pressures off the SE United States will sustain fresh to
strong SW winds across parts of the SW Atlantic, mainly through
Fri night. The high pressure will weaken over the upcoming
weekend, resulting in a decrease in winds and seas across the
area.

$$
GR
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