[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091229
TWDAT

Tropical Weather Discussion...Update
NWS National Hurricane Center Miami FL
1205 UTC Thu Sep 9 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 0900 UTC surface analysis and satellite imagery through
1230 UTC.

Updated Special Features section below

...SPECIAL FEATURES...

Hurricane Larry is centered near 31.2N 61.5W at 09/1200 UTC or
180 nm ESE of Bermuda moving NNW at 14 kt. Estimated minimum
central pressure is 968 mb. Maximum sustained wind speed is 85
kt with gusts to 105 kt. Seas are peaking near 43 ft close to the
center and may increase some during the next day or so. Numerous
strong convection is noted within 90 nm of the center, with
scattered moderate convection noted within 180 nm of the center,
mainly in the SE quadrant. On the forecast track, the center of
Larry should pass east of Bermuda today, and move near or over
southeastern Newfoundland Fri night. Gradual weakening is forecast
during the next couple of days, but Larry is expected to remain a
hurricane into Sat. Please read the latest High Seas Forecast
issued by the National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC
Forecast/Advisory and Public Advisory at www.hurricanes.gov for
more details.

Recently downgraded Tropical Depression Mindy is inland, centered
near 30.8N 83.0W at 09/0900 UTC or 70 nm SSE of Valdosta Georgia
moving NE at 17 kt. Estimated minimum central pressure is 1004 mb.
Maximum sustained wind speed is 30 kt with gusts to 40 kt. Radars
indicate numerous moderate to isolated strong convection within
120 nm of the center in the NE quadrant, with a band of moderate
convection from 29N to 30N between 81W and 87W. Seas are around 8
to 9 ft in Gulf waters near the Florida Big Bend, but this will
continue to quickly diminish this morning. Seas are increasing off
the Georgia and NE Florida coasts, but currently remain below 8
ft. On the forecast track, the center of Mindy is expected to
move into the Atlantic this morning. Mindy is not expected to
restrengthen back over water, with unfavorable upper level winds
likely weakening Mindy further by Fri. Please read the latest
Offshore Zones Forecast issued by the National Hurricane Center at
website https://www.nhc.noaa.gov/text/MIAOFFNT4.shtml and the
latest NHC Forecast/Advisory and Public Advisory at
www.hurricanes.gov for more details.

...TROPICAL WAVES...

An Atlantic tropical wave is near 28W from 18N southward, now just
west of the Cabo Verde Islands, moving W at 10 to 15 kt. A
surface trough is noted in association with this wave. No deep
convection is currently occurring in association with this wave.

Another Atlantic tropical wave is along 45w from 16N southward,
moving W at 10 to 15 kt. A distinct surface trough, separated
behind the wave axis, is noted from 08N42W to 13N40W. Scattered
moderate convection is found from 08N-15N between 38W- 44W.

A third tropical wave is near 67W from 15N southward across
Venezuela, and moving W around 15 to 20 kt. The wave is mainly
monitored through the 700 mb trough diagnostics and the 700 mb
rawindsonde observations. No deep convection is currently
occurring in association with this wave.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through Senegal near 14N17W to 10N29W.
Farther west, the ITCZ extends from 07N43W to 06N55W, inland over
Suriname and French Guiana. Scattered moderate convection is seen
from 05N-08N between 25N-29N.

...GULF OF MEXICO...

Refer to the Special Features section above for details on
Tropical Depression Mindy.

N of 29N and E of 85W, fresh to locally strong SW winds prevail on
the southern periphery of Tropical Depression Mindy. Elsewhere,
mainly gentle winds prevail. Except in the vicinity of Mindy,
seas are only 1-3 ft across the Gulf.

For the forecast, Tropical Storm Mindy moved inland into the Florida
Panhandle overnight and has weakened to a tropical depression
early this morning over SE Georgia. Mindy will continue moving
away from the area, with fresh winds in the NE Gulf diminishing
this morning. Looking ahead, environmental conditions may become
conducive for gradual development of a trough of low pressure over
the Bay of Campeche this weekend and early next week.

...CARIBBEAN SEA...

A weak north-south pressure gradient across the Caribbean is
forcing only fresh E trades over the S central Caribbean and
moderate or weaker trades elsewhere. Seas of 5-6 ft due to swell
from Hurricane Larry continue in the Anegada Passage and the
Mona Passage. Seas are also 5-6 ft over the central Caribbean
with 3-4 ft elsewhere. Scattered moderate convection is noted
from 15N- 19N between 79W-85W.

For the forecast, swells generated by Hurricane Larry will
gradually subside across Atlantic waters of the Leeward Islands,
Puerto Rico, and Hispaniola today. As Larry moves farther north,
the Atlantic ridge will build westward N of the Caribbean Sea
bringing an increase in the trade wind flow tonight into the
weekend. Locally strong winds are possible offshore Colombia,
mainly during the nights.

...ATLANTIC OCEAN...

Please see the Special Features section above for details on
Major Hurricane Larry southeast of Bermuda and Tropical Depression
Mindy moving off the coast of Georgia.

Aside from Hurricane Larry, weak Bermuda/Azores Highs are
centered at 34N45W and 36N24W. with another weak high pressure
centered the Bahamas. The E trades are generally moderate or
lighter across the basin, with the exception being of the very
large wind field of Larry which has fresh or stronger winds around
250 NM radius from the center. Seas are 5-7 ft across the
tropical N Atlantic, except in the vicinity of Larry. No
significant deep convection exists aside that described with
Larry, the tropical waves, and the ITCZ/monsoon trough.

For the forecast, large swells, currently E of 70W, generated by
Hurricane Larry to the east, will continue to propagate to around
80W by tonight, with seas of over 8 ft expected N of the Bahamas.
Seas will then subside into the weekend. Tropical Depression
Mindy, inland over SE Georgia, will move off the coast north of
the area later today and track quickly ENE, causing only a brief
period of fresh to locally strong winds today N of 29N and W of
75W.

$$

Chan
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