[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 210605
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 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 0000 UTC surface analysis and satellite imagery through
0450 UTC.

...SPECIAL FEATURES...

Hurricane Grace is making landfall south of Tuxpan, Mexico. As of
0600 UTC, the hurricane is centered near 20.6N 97.2W or about 25
nm S of Tuxpan, Mexico. Greta is moving W at 9 kt and this general
motion is expected to continue through this evening. Maximum
sustained wind speed is 110 kt with gusts to 120 kt. Peak seas are
currently 37 ft near the center. Estimated minimum central
pressure is 962 mb. An eye is now visible in the latest satellite
imagery. Numerous moderate to strong convection is noted across
the SW Gulf south of 23N, including the W and central Bay of
Campeche. On the forecast track, the center of Grace is
forecast to farther inland over mainland Mexico today. Rapid
weakening is expected as Grace moves inland over the mountains of
central Mexico later today.

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 forecast to become a hurricane today. As
of 0600 UTC, it is centered near 32.4N 73.4W at or 200 nm SSE of
Cape Hatteras, North Carolina, moving N at 8 kt. Maximum
sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are
currently 25 ft near the center. Estimated minimum central
pressure is 994 mb. Numerous moderate to isolated strong
convection is noted from 28N to 34N and between 71W and 75W. A northward to
north-northeastward motion is expected today, with a turn toward
the north-northwest expected late today or tonight. On the
forecast track, Henri is expected to make landfall in Long Island
or southern New England late Saturday night or on Sunday.
Strengthening is forecast during the next 24 hours, and be at or
near hurricane strength when it makes landfall in Long Island or
southern New England. 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...

An Atlantic tropical wave has its axis along 21W, south of 20N,
and it is moving W at 10-15 kt. Scattered moderate convection is
noted from 10N to 14N and between 20W and 25W.

Another Atlantic tropical wave has its axis along 35W, south of
21N, and it is moving W at around 15 kt. Scattered moderate
convection is observed from 05N to 13N and between 30W and 39W.

A third Atlantic tropical wave has its axis along 47W, south of
21N, and it is moving W at around 15 kt. Scattered moderate
convection is present from 06N to 12N and between 42W and 54W.

A Caribbean tropical wave has its axis along 67W, south of 21N,
extending from near Puerto Rico southward to Venezuela, and it is
moving W at around 15 kt. The wave is enhancing the formation of
a few showers and isolated thunderstorms over Venezuela.

Another Caribbean tropical wave has its axis along 77W, south of
20N, extending from E Cuba southward to N Colombia, and it is
moving W near 10 kt. Scattered moderate convection is noted ahead
of the wave axis to the coast of Nicaragua from 11N to 15N.

...MONSOON TROUGH/ITCZ...

A monsoon trough extends from the coast of Mauritania near
19N17W to 13N37W and to 11N50W. The ITCZ then continues from
11N51W to the coast of NE Venezuela near 10N61W. Scattered
moderate convection is present near to 200 nm south of the ITCZ
between 50W and 60W.

...GULF OF MEXICO...

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

Hurricane Grace is the main weather feature dominating the Gulf of
Mexico. A weak surface ridge is positioned over the NE Gulf,
allowing for light to gentle anticyclonic winds across the E and
north-central Gulf with seas of 1-3 ft. Moderate to fresh E-SE
winds are found in the periphery of Grace in the NW and south-
central Gulf. Seas in the area are in the 6-12 ft range.

For the forecast, Grace will make landfall near 20.3N 97.9W Sat
morning, move inland and weaken to a tropical storm near 20.0N
100.9W Sat evening, and dissipate Sun morning. High pressure will
build in the wake of Grace and prevail through early next week.

...CARIBBEAN SEA...

The outer rainbands of Hurricane Grace are enhancing the
formation of showers and thunderstorms over Central America. Most
of the activity is inland or in the E Pacific, however, a few
showers and isolated thunderstorms are affecting the W Caribbean
coast of Guatemala and S Belize. Scattered moderate convection is
also noted south of Hispaniola from 14N to 17N and between 71W and
74W. The rest of the basin enjoys fairly tranquil weather
conditions. Moderate to locally fresh trades are found in the Bay
of Honduras and north-central Caribbean, with seas of 4-6 ft.
Gentle to moderate trades and seas of 2-4 ft prevail elsewhere in
the basin.

For the forecast, moderate to fresh trade winds will dominate,
except localized pulses of strong winds are possible in the Gulf
of Honduras through Sat night. Early next week, fresh to strong
winds will develop over the central Caribbean.

...ATLANTIC OCEAN...

Refer to the Special Features section above for details on
Tropical Storm Henri. ALso, please read the Tropical Waves and
Monsoon Trough/ITCZ sections for additional convection across the
Atlantic Basin.

The tropical Atlantic remains under the dominion of an expansive
1023 mb Azores-Bermuda subtropical ridge. The reliable easterlies
are carrying an outbreak of dry and dusty Saharan air across the
basin, resulting in fairly tranquil weather conditions outside of
the deep tropics and the outer rainbands of Tropical Storm Henri.
A recent scatterometer satellite data show fresh to strong winds
in the periphery of Henri, roughly from 28N to 30N and between 68W
and 76W. Seas in the area are 6-12 ft. Moderate to fresh winds
are found from 13N to 27N and between 35W to the E Bahamas. Seas
in this region are in the 5-7 ft range. Gentle to moderate trades
and seas of 4-6 ft are found elsewhere in the basin.

For the forecast west of 55W, Henri will strengthen to a
hurricane as it continues north of the area to near 34.3N 72.8W
Sat morning, and moving off the coast of the Mid-Atlantic U.S.
Otherwise, 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.

$$
DELGADO
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