[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 181802
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Sun Jul 18 2021

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
1630 UTC.

...TROPICAL WAVES...

An Atlantic tropical wave is along 38W from 20N southward and
moving W near 10 kt. No significant convection is associated this
wave due to subsidence aloft.

A Caribbean tropical wave is near 69W from the Dominican Republic
southward across Venezuela and Colombia, and moving W near 20 kt.
Scattered showers and isolated thunderstorms are noted over the
central Caribbean basin, S Dominican Republic, W Puerto Rico and
E Colombia.

Another tropical wave previously located at the SW Caribbean has
moved inland over Honduras and Nicaragua. It is moving W at 15 to
20 kt and should enter the E Pacific in the next 6 to 12 hours.
Scattered showers and a few thunderstorms are occurring over the
NW Caribbean and SE Mexican coast.

A tropical wave over the Bay of Campeche and S Mexico is moving
W near 10 kt. It will continue westward across S Mexico and the E
Pacific. Scattered showers and thunderstorms are seen at the NW
corner of the Bay of Campeche.

...MONSOON TROUGH/ITCZ...

A monsoon trough stretches from the Gambian coast near 13N17W to
07N37W. Then the ITCZ extends from 07N40W to 09N55W, N of
Suriname. Scattered moderate to isolated strong convection is
evident 05N to 13N between the African coast and 36W. Scattered
showers are present within 60 nm either side of the ITCZ, and N of
Guyana.

...GULF OF MEXICO...

An upper-level trough curves westward from N Florida to the
central Gulf near 26N86W. Scattered moderate convection is found
over the central Gulf, and near New Orleans and the Panhandle.
Refer to the Tropical Waves section above for details on
additional convection.

Surface ridging across the N edge of the Gulf continues to
support light to gentle ESE to SE winds, and seas of 2 to 4 ft
across the entire Gulf.

For the forecast...the Bermuda High extends a ridge westward
along 30N and toward the north-central Gulf Coast. As the ridge
sinks southward through Mon, tranquil conditions will prevail
across the Gulf of Mexico through Thu. Moderate to fresh E winds
will begin pulsing Thu to the NW of the Yucatan Peninsula.

...CARIBBEAN SEA...

Scattered moderate convection is seen over Costa Rica, Panama and
adjacent waters near the E end of a monsoon trough across Panama.
Convergent trade winds are coupling with divergent flow aloft to
trigger scattered moderate convection over and near E Cuba. Please
refer to the Tropical Waves section above for details on
additional convection.

Fresh to strong trades and seas of 8 to 12 ft continue across the
S central basin, N of Colombia and Venezuela. Moderate to locally
fresh trades and seas of 5 to 7 ft prevail across the rest of the
basin.

For the forecast, the Bermuda High north of the area combined
with lower pressure over N Colombia will support fresh to strong
NE to E winds over the central Caribbean through most of the week.
Expect an increase in speed and areal coverage Mon night through
Wed night while reaching as far north as the Hispaniola adjacent
waters. Winds near the coast of NE Colombia and the Gulf of
Venezuela could pulse to strong to near gale force Wed night and
Thu night. Fresh to strong E winds will occur in the afternoons
and early evenings for the next several days in the Windward
Passage. Fresh to strong winds are expected to pulse in the Gulf
of Honduras by Wed night.

...ATLANTIC OCEAN...

Enhanced by upper-level wind shear, convergent trade winds are
producing scattered showers and a few thunderstorms over the SE
Bahamas and N of the Leeward Islands, from 19N to 23N between 62W
and 73W. Please refer to the Tropical Waves and Monsoon
Trough/ITCZ sections above for details on additional convection.

A persistent surface ridge across the central Atlantic basin near
33N promotes light to gentle winds and seas of 2 to 4 ft N of 24N
between 31W and the Florida-Georgia coastline. Moderate to locally
fresh trades and seas of 5 to 7 ft prevail from 10N to 24N
between 29W and the Lesser Antilles, and near the Canarias Islands
N of 25N between the NW African coast and 29W. Gentle to moderate
winds with seas at 4 to 6 ft are found elsewhere.

For the forecast W of 45W, fresh to strong E winds will occur in
the afternoons and early evenings north of Hispaniola for the next
several days. Surface ridging associated with the Bermuda High
will slowly sink southward to 27N by midweek, leading toward
quiescent conditions across the remainder of the western
Atlantic.

$$

Chan
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