[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 281753
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Wed Jul 28 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
1730 UTC.

...TROPICAL WAVES...

An Atlantic tropical wave is along 24W from 18N southward, moving
W near 15 kt. This wave has yet to exit the monsoonal circulation
off of W Africa. Numerous moderate to isolated strong convection
is seen from 07N to 12N between 27W and western Africa.

Another Atlantic tropical wave is along 41W from 19N southward,
moving W 15-20 kt. Satellite imagery suggest that this wave is
surrounding by a broad area of Saharan air that is inhibiting deep
convection.

A Caribbean tropical wave has been relocated to 76W from 13N
southward across Colombia, moving W at 20-25 kt. No deep
convection is associated with this wave as dry stable air is
immediately located behind this wave across the E Caribbean.

Another tropical wave in the western Caribbean is along 90W from
Guatemala southward into the eastern Pacific, moving W near 10 kt.
Enhanced by an elongated upper-level low just to the NW of the
wave, scattered moderate to strong convection is present from 15N
to 20N between 88W and 89W, including coastal sections of Belize
and Yucatan Peninsula.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends across the Mauritania coast at 17N16W to
07N39W. The ITCZ then continues from 07N39W to the coast of
Suriname at 06N42W. Beyond convection described above associated
with the tropical waves, the Saharan Air Layer is limiting any
further convection.

...GULF OF MEXICO...

A surface trough is over the W central Gulf from 29N90W to
23N93W. An upper-level low is centered across the NW Gulf near
26N97W. This combination is triggering scattered moderate
convection from 27N to 28N between 93W and the central Gulf Coast
of Florida. Isolated showers are noted off the northeast coast of
Mexico and the southwest Bay of Campeche. Elsewhere, light to
gentle winds near the W periphery of the Atlantic ridge prevail
across the basin, with seas of 1 to 3 feet.

The surface trough remains over the W central Gulf aligned NE to
SW, and is accompanied by scattered showers and isolated
thunderstorms. The trough will drift toward the NW Gulf and
weaken through Thu. In its wake, the Atlantic high pressure will
begin to build westward into the Gulf waters on Thu, with a
ridge persisting along 27N into Sun.

...CARIBBEAN SEA...

Convergent trade winds behind the tropical wave along 90W are
producing scattered strong convection over the western basin, into
coastal Nicaragua and scattered moderate convection over the
southern Gulf of Honduras. Dry stable low level air and generally
fair weather prevails to the east of this area. Gentle to moderate
trades S of the Atlantic ridge dominate the entire Caribbean
basin. Seas of 2 to 4 ft are present over the W basin, and 4 to 6
ft are found over the central and E basin, except to 7 ft off the
NW coast of Colombia.

Gentle to moderate trade winds are expected across the basin
through Thu. The exception will be moderate to locally fresh winds
near the coast of Colombia, in the Gulf of Venezuela and Gulf of
Honduras, and S coast of Hispaniola. Winds will begin to increase
across the E and central Caribbean tonight through Thu night, then
persist through the weekend, as the Atlantic ridge builds
westward in the wake of a trough moving westward across the Atlc
waters north of the Greater Antilles.

...ATLANTIC OCEAN...

Scattered moderate convection is noted over the central Bahamas
and Great Bahama Bank. For convection elsewhere across the
Atlantic Basin, refer to the Tropical Waves and Monsoon
Trough/ITCZ sections.

The Atlantic ridge extends WSW from a 1029 mb Azores high, across
Bermuda to northern Florida. This ridge supports light to gentle
winds and seas of 3 to 5 ft N of 24N between 40W and the Georgia-
Florida coast. Scatterometer and altimeter data reveal gentle to
moderate trades and seas of 4 to 6 ft from 19N to 24N between 47W
and the Lesser Antilles. Dry and stable atmospheric conditions
across this region are producing generally fair weather. Moderate
to fresh trades and seas around 6 to 8 ft are evident near the
Canaries Islands N of 19N between the NW African coast and 29W.
Gentle to locally moderate SE trades and seas of 5 to 7 ft prevail
across the rest of the basin.

An inverted trough located along 65W south of 23N will move
quickly westward across the SE waters this morning, then continue
north of the Greater Antilles and across the southern Bahamas
through Thu. Expect fresh to locally strong easterly winds late
afternoon through the night just off the N of Hispaniola,
including approaches to the Windward Passage, most of the forecast
period.


$$

Nepaul/Rivera
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