[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 212330
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sun Aug 22 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 1800 UTC surface analysis and satellite imagery through
2315 UTC.

...SPECIAL FEATURES...

The remnants of Grace are centered near 19.6N 100.1W at 21/2100
UTC or 60 nm WNW of Ciudad De Mexico moving W at 11 kt. Estimated
minimum central pressure is 1002 mb. Maximum sustained wind
speed is 20 kt with gusts to 25 kt. Peak seas are currently 9 ft
near Tampico, Mexico. Scattered moderate convection is noted
over central Mexico. Grace is being affected by the mountainous
terrain across central Mexico, and has lost most of the strong
convection. Although Grace has dissipated, its remnants will likely
move into the eastern North Pacific by Sunday afternoon, where it
is likely to develop into a new tropical cyclone next week.
Please read the latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for
more details.

Hurricane Henri is centered near 36.3N 71.4W at 21/2100 UTC or
210 nm ENE of Cape Hatteras North Carolina moving NNE at 16 kt.
Estimated minimum central pressure is 991 mb. Maximum sustained
wind speed is 65 kt with gusts to 80 kt. Seas of 12 ft or
greater prevail within 180 nm E semicircle, 90 nm SW quadrant and
160 nm NW quadrant, with maximum seas of 33 ft. Numerous
moderate and isolated strong convection is noted from 34N-38N
between 67W-72W. On the forecast track, Henri is expected to
make landfall on Long Island or in southern New England on
Sunday. Strengthening is forecast through tonight.  Although some
weakening is expected prior to landfall on Sunday, Henri is forecast
to be at or near hurricane strength when it reaches the coasts of
Long Island and southern New England. Please read the latest NHC
Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml
and Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details.

...TROPICAL WAVES...

An Atlantic tropical wave extends its axis along 28W from 22N
southward and moving W at 15 to 20 kt. Scattered moderate
convection is noted from 05N to 14N between 24W and 32W.

Another Atlantic tropical wave extends its axis near 39W from
19N southward and moving W at 10 to 15 kt. Scattered moderate
convection is noted from 10N to 13N between 35W and 40W.

A third Atlantic tropical wave extends its axis along 52W from
21N southward and moving W near 15 kt. Scattered moderate
convection is present from 10N to 15N and between 47W and 55W.

A Caribbean tropical wave extends its axis along 72W from 21N
southward across Hispaniola to NW Venezuela and moving W near 15
kt. Drier air at the mid levels continue to hinder significant
convection near this wave.

Another Caribbean tropical wave is along 80W from 20N southward
across central Panama to the E Pacific Ocean, and moving W at 10
to 15 kt. This wave is well depicted in satellite imagery, as
well as scatterometer data. Scattered too numerous moderate
convection prevails from 15N to 20N between 76W and 85W.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends from the coast of Africa near the
Senegal-Gambia border at 14N17W to 11N42W. The ITCZ then
continues from 11N42W to 13N50W. Aside from the convection
related to the tropical waves described in the section above, a
large area of moderate convection is developing over coastal
Africa and exiting the landmass south of 13N and east of 19W.
Scattered moderate convection is evident from 05N to 16N between
24W and 55W.

...GULF OF MEXICO...

Refer to the Special Features section above for details on
Remnants of Grace now inland over central Mexico.

A surface ridge extends across the basin anchored by a 1017 mb
high centered near 29N87W. Modest convergent winds along the N
periphery of the high is coupling with northerly wind shear aloft
to trigger scattered showers and isolated thunderstorms currently
developing across the Florida peninsula. Light to gentle SE to S
winds and seas of 3 to 5 ft are evident over the N and E Gulf.
Moderate to fresh with locally strong ESE to SE winds and seas at
6 to 10 ft are seen across the SW Gulf, including the Bay of
Campeche.

For the forecast, Tropical Storm Grace continues moving westward through
Mexico, away from the area, and no further impacts are
anticipated. High pressure will build in the wake of Grace and
prevail through early next week.

...CARIBBEAN SEA...

Refer to the section above for details on the tropical waves
moving across the basin.

Modest convergent trade winds are triggering scattered showers
near the Windward Islands.

Moderate to fresh NE to ENE trades and seas at 4 to 7 ft are
present across the E and central basin. Gentle to moderate trades
and seas of 4 to 5 ft prevail for the rest of the basin.

For the forecast, moderate to fresh trade winds will dominate
into next week. Pulses of strong winds are possible offshore
Colombia starting tonight and will develop over much of the rest
of the central Caribbean later on Sun.

...ATLANTIC OCEAN...

Refer to the sections above for details on Hurricane Henri N of
the area and the tropical waves moving across the basin.

The Atlantic ridge stretching from the 1022 mb Azores high
across Bermuda to S Florida continues to support light to gentle
winds and seas of 3 to 5 ft, N of 25N between 32W and 64W. N of
29N, moderate to fresh SSE to SW winds and seas of 6 to 9 ft are
seen between 64W and 68W, and between 75W and 77W; strong to
near-gale S to SW winds and seas at 9 to 11 ft are found between
68W and 75W. Gentle to moderate NE trades and seas at 5 to 6 ft
are evident from 13N to 25N between 33W and Lesser
Antilles/Bahamas, and also near the Canaries Islands N of 20N
between the NW African coast and 33W. Gentle to moderate SE to SW
winds and seas of 4 to 6 ft prevail for the remainder of the
Atlantic Basin. Latest satellite loop suggests the leading edge
of Sahara Dust to be near 38W.

For the forecast west of 55W, Hurricane Henri is now well north
of the area and will continue moving away from the region today,
with no further impacts expected. Moderate to fresh E to SE winds
will prevail E and across the Bahamas through Mon, except for
fresh to possibly locally strong winds at night north of
Hispaniola and the approaches to the Windward Passage. A tropical
wave will move across the area by mid-week with fresh to strong
winds ahead of it.

$$
ERA
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