[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251757
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Tue Jul 25 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
1700 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is east of the Cabo Verde
Islands near 21W from 19N southward, and moving west around 10
kt. Scattered moderate convection is noted from 08N to 19N between
the central Africa coast and 26W.

A central Atlantic tropical wave is near 39W from 19N southward,
and moving west around 15 kt. Most of the wave north of 10N is
enveloped by dry Saharan dust, thus no deep convection is present
at this time.

An eastern Caribbean tropical wave, Invest AL95 is near 63W from
near Anguilla southward into northeastern Venezuela. It is moving
west at 15 to 20 kt. Scattered heavy showers and isolated
thunderstorms with gusty winds are occurring across the eastern
Caribbean Sea, including the Lesser Antilles. There is a low
chance of tropical cyclone development for this wave during the
next 7 days.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic near the Mauritania/Senegal
border, then curves southwestward through 10N30W to 08N47W.
Scattered moderate convection is evident up to 100 nm north, and
200 nm south of the trough west of 28W. An ITCZ continues
northwestward from 08N47W to near the Windward Islands at 13N61W.
Widely scattered showers are noted near and up to 160 nm south of
the ITCZ.

...GULF OF MEXICO...

A very weak stationary front drapes across the north-central Gulf
from near New Orleans to the Florida Panhandle, no convection is
observed near this feature. A surface trough is causing scattered
showers and thunderstorms at the northwestern and north-central
Gulf, southwest and south of New Orleans. Another surface trough
is producing similar conditions at the western Bay of Campeche.

A surface ridge extending west-southwestward from a 1021 mb high
at the central Gulf to just south of Brownsville, Texas is
dominating the rest of the Gulf. Light to gentle winds and seas of
1 to 3 ft are seen across the northern Gulf. Gentle to moderate
ENE to SE winds and 2 to 4 ft seas prevail for the southern Gulf,
including the Bay of Campeche and Florida Straits.

For the forecast, the surface ridge will remain the dominant
feature across the basin into late this week. This will support
gentle to moderate winds, except over the eastern Bay of Campeche
where winds will be enhanced by a thermal trough that emerges off
the Yucatan Peninsula nightly. The surface trough to the south of
the stationary front will remain the focus for showers and
thunderstorms for the next couple of days.

...CARIBBEAN SEA...

An upper-level low near 20N84W is triggering isolated
thunderstorms at the northwestern basin. Refer to the Tropical
Waves sections above for additional weather in the Caribbean
Basin. Tight gradient between the Atlantic Ridge to the north near
27N and Colombian Low are causing fresh to strong ENE winds and
seas of 8 to 10 ft at the south-central and southwestern basin,
mainly north of Colombia. Moderate to fresh with locally strong
ENE to ESE winds and 5 to 8 ft seas are noted for the eastern
basin. Moderate to fresh ENE winds and seas at 4 to 6 ft are
present at the north-central basin. Gentle to moderate ENE to E
winds and 3 to 5 ft seas prevail for the rest of the basin.

For the forecast, the tight pressure gradient will maintain
fresh to strong trades across the southwestern and south-central
basin the next couple of days. Winds should diminish to between
moderate and fresh by Wed. The tropical wave, Invest AL95 is
expect to track westward across the eastern and central basin
over the next few days, generating locally heavy rains and strong
gusty winds.

...ATLANTIC OCEAN...

Enhanced by an upper-level low north of Puerto Rico near 24N66W,
a surface trough south-southwest of Bermuda near 27N69W is
producing scattered moderate convection from 23N to 30W between
65W and 74W. Isolated thunderstorms are found farther west over
the northwest Bahamas and near southeastern Florida. The northern
tip of a tropical wave near the northern Leeward Islands is
causing widely scattered showers and isolated thunderstorms near
Puerto Rico and the Virgin Islands. Refer to the Monsoon
Trough/ITCZ and Tropical Waves sections at the beginning for
additional weather in the Atlantic Basin.

Gentle southerly winds and seas of 2 to 4 ft exist from the
northwest Bahamas northward to beyond 31N west of 30W. Otherwise,
a large dome of 1029 mb Mid-Atlantic High near 34N48W supports
gentle to moderate with locally fresh NE to E winds and 5 to 7 ft
seas north of 20N between the Africa coast and 30W, including the
Canary Islands. Moderate to fresh easterly trades and seas of 3 to
5 ft exist across the central and southeast Bahamas. Just east of
the Lesser Antilles, moderate to fresh ESE winds and seas at 6 to
8 ft are present from 11N to 20N between 55W and the Lesser
Antilles. Farther east, gentle to moderate NNE to ENE trades and 4
to 6 ft seas dominate from 11N to 20N between the central Africa
coast and 55W. Gentle to moderate southerly and monsoonal westerly
winds with seas at 4 to 7 ft in moderate southerly swell prevail
elsewhere in the Atlantic Basin.

For the forecast west of 55W, the modest surface ridge dominating
the western Atlantic will gradually shift northward this week.
This is in response to the surface trough south-southwest of
Bermuda moving west-northwestward towards the southeastern U.S.
coast later this week and into the weekend. Fresh trades will
pulse nightly north of Hispaniola and over the Windward Passage.
Elsewhere west of 55W, winds will be moderate or weaker over most
of the area, except moderate to fresh northeast of the Leeward
Islands.

$$

Forecaster Chan
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