[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 182331
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Thu Aug 19 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
2300 UTC.

...SPECIAL FEATURES...

Hurricane Grace is centered near 19.7N 83.7W at 18/2100 UTC or
220 nm E of Tulum Mexico moving WNW at 14 kt. Estimated minimum
central pressure is 992 mb. Maximum sustained wind speed is 70
kt with gusts to 85 kt. Numerous moderate and scattered strong
convection is noted from 16N-21N between 80W-85W. Peak seas are
25 ft. A general west-northwestward to westward motion is
expected for the next several days.  On the forecast track,
Grace is expected to make landfall in the eastern Yucatan
Peninsula Thursday morning, move over the Yucatan Peninsula on
Thursday, and move over the southwest Gulf of Mexico Thursday
night or early Friday. Weakening will occur while the center
moves over the Yucatan Peninsula on Thursday, with
restrengthening expected when Grace moves over the southwest
Gulf of Mexico on Friday. Seas may reach 30 ft in the NW
Caribbean before landfall in Yucatan and then redevelop to 25 ft
in the SW Gulf of Mexico. 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 29.9N 67.6W at 18/2100 UTC
or 200 nm SW of Bermuda moving W at 8 kt. Estimated minimum
central pressure is 995 mb. Maximum sustained wind speed is 60
kt with gusts to 75 kt. Peak seas are near 20 ft. Numerous
moderate and scattered strong convection is noted from 28N-32N
between 65W-69W. A turn to the north is expected on Friday with
that motion continuing into the weekend. Little change in
strength is forecast during the next day or so, but Henri is
expected to become a hurricane on Friday. Peak seas should
continue near 20 ft through Friday morning, before diminishing
in our waters as Henri moves northward. 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 was identified near 23W from 19N
southward. Scattered moderate convection is seen from 03N-13N
between 22W-28W.

A far eastern Atlantic tropical wave has its axis along 34W from
19N southward, moving westward at around 10 kt. Scattered
moderate convection is seen from 07N-13N between 30W-38W.

A central Atlantic wave has its axis along 51W south of 20N,
moving westward at 15 kt. No significant deep convection is
currently associated with this wave.

A tropical wave over the eastern Caribbean has its axis along
66W from 20N southward, moving westward at 15 kt. No significant
deep convection is currently associated with this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from Senegal near 12N18W to
09N50W. The ITCZ then extends from 08N51W to 09N61W. Aside from
the convection associated with the tropical waves along 26W,
no significant deep convection is occurring.

...GULF OF MEXICO...

Fairly tranquil weather conditions prevail across most of the
Gulf of Mexico. However, moderate to fresh NE to E winds are
over the SE Gulf waters including the Yucatan Channel.
Elsewhere, light and gentle winds prevail in the basin north of
24N with seas 3-5 ft in the SE Gulf and 1-3 ft elsewhere. No
significant deep convection is currently occurring over the Gulf.

For the forecast, Hurricane Grace near 19.7N 83.7W 992 mb at 5
PM EDT moving WNW at 14 kt. Maximum sustained winds 70 kt gusts
85 kt. Grace will move to 20.2N 86.1W Thu morning, move inland
and weaken to a tropical storm near 20.7N 89.3W Thu afternoon,
20.9N 92.2W Fri morning, strengthen to a hurricane near 20.8N
94.6W Fri afternoon, inland to 20.4N 97.3W Sat morning, and move
inland and weaken to a tropical depression near 20.0N 99.9W Sat
afternoon. Winds and seas will begin to increase across the
southeastern Gulf ahead of Grace tonight. These conditions will
shift to west of 90W Thu through late Fri night.

...CARIBBEAN SEA...

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

Outside of the wind field of Tropical Storm Grace, strong to
near gale-force NE to E trades in the south-central Caribbean
Sea, especially within 90 nm of the NW coast of Colombia. Fresh
to strong trades are noted in the rest of the central and E
Caribbean. Gentle to moderate trades are found in the rest of
the basin. Latest observations indicate seas are 5-7 ft in the
central and E Caribbean, and 1-3 ft SW Caribbean.

For the forecast, Hurricane Grace near 19.7N 83.7W 992 mb at 5
PM EDT moving WNW at 14 kt. Maximum sustained winds 70 kt gusts
85 kt. Grace will move to 20.2N 86.1W Thu morning, move inland
and weaken to a tropical storm near 20.7N 89.3W Thu afternoon,
20.9N 92.2W Fri morning, strengthen to a hurricane near 20.8N
94.6W Fri afternoon, inland to 20.4N 97.3W Sat morning, and move
inland and weaken to a tropical depression near 20.0N 99.9W Sat
afternoon. Elsewhere, fresh to strong trades will be over the
central Caribbean through early Thu.

...ATLANTIC OCEAN...

Please refer to the sections above for details on Tropical Storm
Henri and on the tropical waves moving across the basin.

An expansive 1026 mb Azores ridge dominates the tropical
Atlantic, resulting in fairly tranquil weather conditions. The
strong high pressure system and lower pressures over NW Africa
result in a tight pressure gradient over the NE Atlantic. Fresh
to strong NE winds are occurring surrounding the Canary Islands
and off the coasts of Morocco and Western Sahara. Seas in this
area are in the 5-7 ft range. Elsewhere the NE to E trades are
moderate to fresh. Seas are generally 5-7 ft.

For the forecast west of 65W, Tropical Storm Henri near 29.9N
67.6W 995 mb at 5 PM EDT moving W at 8 kt. Maximum sustained
winds 60 kt gusts 75 kt. Henri will move to 29.8N 69.0W Thu
morning, 29.8N 70.7W Thu afternoon, strengthen to a hurricane
near 30.1N 72.3W Fri morning, 31.0N 73.2W Fri afternoon, 32.7N
72.7W Sat morning, and 35.2N 71.7W Sat afternoon. Elsewhere,
high pressure will persist across the forecast waters through
the period. Fresh east to southeast winds over the far southwest
part of the area will shift W to the Straits of Florida tonight.

$$
Landsea/MTorres
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