[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 202333
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Sat Aug 21 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
2220 UTC.

...SPECIAL FEATURES...

Hurricane Grace is centered near 20.5N 95.1W at 2100 UTC or about
100 nm NE of Veracruz, Mexico, moving W at 9 kt. Maximum
sustained wind speed is 80 kt with gusts to 100 kt. Peak seas are
currently 32 ft. Estimated minimum central pressure is 979 mb.
Numerous moderate to strong convection is noted across the SW
Gulf south of 22.5N, including the W and central Bay of Campeche.
Grace will track westward across the SW Gulf and reach near the
coast at 20.4N96.6W tonight, then move inland and weaken to a
tropical storm near 19.9N 98.9W Sat afternoon, move into
Michoacan, Mexico, Sat night, and dissipate Sun afternoon. 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.

Tropical Storm Henri is centered near 31.2N 73.9W at 2100 UTC or
255 nm SSE of Cape Hatteras, North Carolina, moving N-NW at 6 kt.
Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak
seas are currently 25 ft. Estimated minimum central pressure is
994 mb. Numerous moderate to isolated strong convection is noted
from 29N to 32N between 72W and 74W. Henri is nearing hurricane
strength and is expected to become a hurricane tonight as it
reaches near 32.8N 73.3W, then continue northward and out of the
discussion area, moving toward coastal New York Sun. Moderate
northeast swell from Henri will impact coastal areas from central
Florida to Georgia and the Carolinas tonight through Sat. 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...

A new Atlantic tropical wave is just off the African coast near
18W-19W from 20N southward and moving W at 10 kt. Scattered
moderate isolated strong convection is seen from 11N to 13.5N
between 18W and 26W.

Another Atlantic tropical wave is along 34W from 20N southward
and moving W at 15 to 20 kt. Scattered moderate convection is
noted from 05N to 13N between 30W and 37W.

A third Atlantic tropical wave is near 46W from 21N southward of
and moving W at 15 to 20 kt. Scattered moderate convection is
present from 07N to 12N between 43W and 50W.

A Caribbean tropical wave is along 66W from 21N southward across
Puerto Rico to Venezuela, and moving W at 15 to 20 kt. Scattered
showers and isolated thunderstorms are from 14N to 19N between 64W
and 73W. This wave has also dragged the ITCZ northward across the the
Windward Islands and into E central Caribbean along 63W.

Another Caribbean tropical wave is near 76W-77W from E Cuba
southward to N Colombia, and moving W near 10 kt. Deep layered dry
air is hindering significant convection from flaring up near this
wave.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends from the coast of Senegal near 14.5N17W
to 16.5N22W to 10N50W. The ITCZ then continues from 10N50W to
14N63W. Scattered moderate convection is present near the monsoon
trough 05N to 14N between 35W and 42W. Scattered showers are
evident near the ITCZ from 09N to 12N between 50W and 56W.

The E Pacific monsoon trough extends into the SW Caribbean Sea
from near the Costa Rica-Panama border to northern Colombia.
Scattered showers and thunderstorms are flaring up across Panama
and Costa Rica and their immediate Caribbean coastal waters.

...GULF OF MEXICO...

Refer to the Special Features section above for details on
Hurricane Grace.

Other than Hurricane Grace, a surface ridge reaches southeastward
from the NE Gulf through S Florida; providing light to gentle S
to SE and seas at 2 to 5 ft east of 90W. Moderate to fresh E to
SE winds and seas of 6 to 12 ft are found near the NW and central
Gulf, where building SE swell is reaching the Mexican coastlines.

Grace will move near the Mexican coast to 20.4N 96.6W tonight then
move inland and weaken to a tropical storm near 19.9N 98.9W Sat
afternoon. Grace will weaken to a tropical depression near
Michoacan, Mexico, Sun morning and dissipate Sun afternoon. High
pressure will build in the wake of Grace and prevail through early
next week.

...CARIBBEAN SEA...

Convergent trade winds are coupling with divergent winds aloft to
produce scattered showers and thunderstorms over Hispaniola and
the central Caribbean Basin, ahead of the tropical wave along 66W.

Moderate to fresh E to SE winds and seas at 5 to 7 ft are noted
along the E coast of the Yucatan Peninsula, and the N central
basin. Gentle to moderate trades and seas of 4 to 6 ft prevail for
the rest of the basin.

Moderate to fresh trade winds will dominate the basin through the
weekend, except localized pulses of strong winds are possible in
the Gulf of Honduras tonight. Early next week, fresh to strong
winds will develop over the central Caribbean as high pressure
builds across the Atlantic in the wake of Henri.

...ATLANTIC OCEAN...

Refer to the Special Features section above for details on
Tropical Storm Henri. Convergent winds feeding toward Tropical
Storm Henri are producing scattered showers and isolated
thunderstorms N of the Bahamas, N of 27N between 75W and 79W.
Please read the Tropical Waves and Monsoon Trough/ITCZ sections
for additional convection across the Atlantic Basin.

The Atlantic ridge stretches from the 1022 mb Bermuda high near
31N55W, extending SW to S Florida. Light to Gentle winds and seas
at 3 to 5 ft are found N of 27N between the NW African coast and
67W. Moderate to fresh with locally strong winds and seas of 5 to
8 ft are present N of 28N, E of Tropical Storm Henri between 67W
and 71W, and also W of Henri between 75W and 77W. Gentle to
moderate NE trades and seas of 4 to 7 ft are found from 16N to 27N
between the African coast and Lesser Antilles. Light to gentle SE
to S winds and seas at 3 to 4 ft are evident across the Bahamas
and near the E Florida coast. Gentle to moderate winds and seas at
4 to 6 ft prevail for the rest of the basin.

For the forecast west of 55W, Tropical Storm Henri Henri will
strengthen to a hurricane near 32.8N 73.3W tonight, then move to
35.8N 72.3W Sat afternoon. By Sun morning, Hurricane Henri will be
well north of the area, off the coast of the Mid-Atlantic U.S.
Otherwise, moderate to fresh E to SE winds will prevail E and
across the Bahamas Fri through Mon, except for fresh to possibly
locally strong winds at night north of Hispaniola and the
approaches to the Windward Passage.

$$
Stripling
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