[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080417
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Tue Aug 8 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 0000 UTC surface analysis and satellite imagery through
0415 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 26W, south of
18N, moving westward at 10 kt. No deep convection is noted near
the wave axis.

A central Atlantic tropical wave has its axis along 45W, south of
19N, moving westward at 10 kt. Scattered moderate convection is
observed from 06N to 09N and between 43W and 46W.

A tropical wave is approaching the Lesser Antilles. The axis of
the wave is along 59W, south of 21N, moving westward at 10-15 kt.
Scattered moderate to isolated strong convection is noted from
12N to 22N and 55W and 65W.

A central Caribbean tropical wave has its axis along 75W, south of
20N, moving westward at 10-15 kt. No significant convection over
water is noted near the tropical wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of The
Gambia near 13.5N17W and continues westward to 13N37W. The ITCZ
extends from 13N37W to 10N45W and from 10N47W to 11N55W. Scattered
moderate to isolated strong convection is evident from 06N to 15N
and between 31W and 41W. Similar convection is observed from 06N
to 12N and between 48W and 55W.

GULF OF MEXICO...

The subtropical ridge extends westward into the Gulf of Mexico,
anchored by a local 1019 mb high pressure system located near
26N91W. A few showers and isolated thunderstorms that developed
earlier today in the Yucatan peninsula are propagating westward
across the eastern Bay of Campeche. Similarly, isolated showers
and thunderstorms are noted off NW Cuba and SW Florida. The weak
pressure gradient promotes primarily moderate or weaker
anticyclonic winds. Seas of 2-3 ft are noted west of 90W and 1-2
ft elsewhere.

For the forecast, relatively weak high pressure over the area
will support gentle to moderate winds over most of the basin
during the next several days. Moderate return flow across the far
western Gulf will become moderate to fresh by early Wed,
continuing through most of the week. A thermal trough will move
off the Yucatan Peninsula each night, producing moderate to fresh
winds to the northwest of the Yucatan Peninsula through most of
the week.

CARIBBEAN SEA...

Scattered showers and isolated thunderstorms are seen in the
nearshore waters of southern Cuba and Hispaniola, especially the
Gulf of Gonave. Similar storm activity is affecting northern
Colombia and Panama and extending to the nearshore waters.
Elsewhere, a generally dry airmass suppresses the development of
deep convection. The pressure gradient between the ridge north of
the islands and lower pressures in northern South America support
fresh to occasionally strong easterly trade winds in the central
Caribbean, along with seas of 4-7 ft. The strongest winds are seen
on the latest scatterometer satellite data in the Gulf of
Venezuela. Moderate or weaker winds and slight to moderate seas
prevail in the rest of the basin.

For the forecast, fresh to strong trade winds will prevail over
the south-central Caribbean through Tue, with fresh trade winds
over the central Caribbean. Meanwhile, moderate to fresh trades
are expected over the eastern basin, with gentle to moderate
trades are expected in the western basin. Winds across the
Caribbean will diminish slightly Tue night into early Wed through
Thu. A tropical wave will move into the eastern Caribbean late Thu
into Fri, bringing fresh to locally strong winds and moderate
seas.

ATLANTIC OCEAN...

A 1025 mb subtropical ridge positioned near 29N52W dominates the
tropical Atlantic, maintaining fairly tranquil weather conditions
outside of the deep tropics. There are a few exceptions, including
divergence aloft producing a few showers north of 29N and between
62W and 67W. Similar activity is noted between SE Florida and
Andros Island. Scattered moderate convection is also seen south of
22N and west of 55W in association with the tropical wave in the
area as mentioned in the Tropical Waves section. These storms are
also affecting Puerto Rico and the US Virgin Islands.

Moderate to locally fresh easterly trade winds due to the pressure
gradient between the ridge and lower pressures in the tropics are
found south of 26N and west of 37W. Seas in these waters are 5-7
ft. Moderate or weaker winds and moderate seas prevail elsewhere.

For the forecast W of 55W, the subtropical ridge axis will
continue to be situated along 28N through much of the week. Fresh
E trade winds S of 25N and E of 75W will diminish to mostly
moderate speeds Tue night into Wed. Seas generated by these winds
will gradually subside tonight. Winds off the N coast of
Hispaniola will pulse to strong speeds this evening, then pulsing
moderate to locally fresh Tue through Thu. Winds will then
increase to fresh to locally strong speeds through Sat night as
the northern portion of a tropical wave moves across the
southeastern forecast waters late in the week. The Bahamas can
expect increased winds Sat and Sat night.

$$
DELGADO
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