[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 231759
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Mon Aug 23 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
1700 UTC.

...TROPICAL WAVES...

An Atlantic tropical wave is along 21W from 19N southward and
moving W near 15 kt. Scattered moderate to isolated strong
convection is seen from 02N to 10N between 18W and 28W.

A well defined Atlantic tropical wave is near 38W from 20N
southward and moving W at 15 to 20 knots. Scattered moderate
convection is present from 09N to 19N between 35W and 39W.

A weak Atlantic tropical wave is along 52W from 18N southward and
moving W near 15 knots. Much drier air at mid and upper levels is
hindering any significant convection near this wave.

A robust Caribbean tropical wave is near 64W from 20N southward
across the Virgin Islands to E Venezuela, and moving W near 10
kt. Enhanced by strong trade-wind convergence in the vicinity,
scattered showers and isolated thunderstorms are occurring across
the S central and SE Caribbean Basin, and farther E into the
Atlantic from 9N to 14N between 55W and the Windward Islands.

Another Caribbean tropical wave is along 83W from 20N southward
across the Costa Rica-Panama border into the E Pacific, and
moving W at 10 to 15 knots. Scattered showers and a few
thunderstorms are present near the coast of Honduras, Nicaragua,
Costa Rica and Panama.

A tropical wave is over the E Bay of Campeche near 90W from 21N
southward across S Mexico and Guatemala into the E Pacific, and
moving W near 15 kt. Scattered showers and thunderstorms are
evident along the E coast of the Yucatan Peninsula and over
Belize.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends from the African coast near the
Mauritania-Senegal border at 16N16W through a 1011 mb low
pressure near 13N41W to 09N46W. Scattered moderate convection is
seen S of the low from 06N to 11N between 39W and 43W. No ITCZ is
present based on the latest analysis.

...GULF OF MEXICO...

A surface ridge extends east-southeastward from a 1017 mb high
near the Texas-Louisiana border across the N central Gulf to
central Florida. Convergent surface winds N of the ridge axis are
coupling with modest divergence aloft to trigger scattered showers
and isolated thunderstorms from near New Orleans eastward across
N Florida. An upper-level low over E central Mexico at 21N100W is
producing similar conditions over the SW Gulf, including the W Bay
of Campeche. Moderate to locally fresh winds and seas up to 4 ft
are expected near strong thunderstorms. Otherwise, light to Gentle
E to ESE winds associated with the ridge and seas at 1 to 3 ft
prevail across much of the Gulf.

For the forecast, high pressure will dominate the basin through
Fri producing mainly gentle to moderate E to SE winds. Fresh winds
will pulse west of the Yucatan Peninsula tonight and again Tue
night.

...CARIBBEAN SEA...

Convergent trade winds are causing scattered showers and isolated
thunderstorms over the W central basin, N of Panama and Colombia.
Please refer to the Tropical Waves section above for additional
convection across the Caribbean Basin.

The latest satellite scatterometer and altimetery data reveal
fresh to strong NE to E trade winds and seas at 5 to 7 ft across
the central and E basin. Gentle to moderate trades and seas of 2
to 4 ft prevail for the rest of the basin.

For the forecast, fresh to strong trade winds will dominate most
of east and central Caribbean through midweek, building seas to
between 8 and 10 ft. Fresh to locally strong winds are also
expected in the Windward passage through Tue night. A tropical
wave currently over the eastern Carribbean seas may induce the
formation of a broad low pressure in the SW Caribbean Sea late
this week.

...ATLANTIC OCEAN...

Enhanced by an upper-level trough along the US E Seaboard near
34N74W, convergent SE winds are creating scattered showers and
thunderstorms off the Georgia-N Florida coast, N of 29N between
73W and 79W. Please refer to the Tropical Waves and Monsoon
Trough/ITCZ sections above for additional convection across the
Atlantic Basin.

The Atlantic ridge curves westward from the 1024 mb Azores high
near 34N23W to the Bermuda high near 32N63W. These features
continue to provide gentle to moderate winds and seas of 3 to 5 ft
N of 23N between 23W and the Georgia-Florida coast. Moderate to
fresh with locally strong trade winds and seas at 7 to 10 ft are
found near the Canary Islands N of 16N between the NW African
coast and 23W, and W of the Cape Verde Islands from 08N to 22N
between 34W and 40W. Moderate to fresh trades and seas of 5 to 6
ft are found from 10N to 23N between 50W and the Lesser Antilles.
Gentle to moderate SE to S winds and seas at 5 to 7 ft prevail for
the rest of the Atlantic Basin.

For the forecast W of 65W, high pressure located near Bermuda
will dominate the region through at least Wed. A surface trough
is forecast to approach from the E on Thu, possible reaching the
NE waters on Fri. Fresh to locally strong winds are expected N of
Hispaniola including the approaches to the Windward Passage
through Tue night. The pressure gradient could increase some
across the SW N Atlantic Tue night into Wed between the high
pressure located just N of Bermuda and the approaching surface
trough.

$$

Chan
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