[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100009
TWDAT

Tropical Weather Discussion...UPDATED
NWS National Hurricane Center Miami FL
0009 UTC Fri Sep 10 2021

Updated to include the information in the intermediate advisory
on Hurricane Larry

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
2345 UTC.

...SPECIAL FEATURES...

Hurricane Larry is centered near 34.2N 62.3W at 10/0000 UTC or
165 nm NE of Bermuda moving NNW at 18 kt. Estimated minimum
central pressure is 966 mb. Maximum sustained wind speed is 80
kt with gusts to 100 kt. Seas are peaking near 40 ft about 400 nm
in the NE quadrant and 280 nm SE quadrant. Numerous moderate to
strong convection is noted in 180 nm NE quadrant and scattered
moderate convection is seen about 100 nm in the SW quadrant. On the
forecast track, the center of Larry will continue to move away from
Bermuda tonight, and move near or over southeastern Newfoundland
Friday night or early Saturday morning. Gradual weakening is
forecast to begin on Friday, but Larry is expected to remain a
hurricane until it passes Newfoundland. Larry should become an
extratropical cyclone on Saturday, then weaken further while it
passes southeast of Greenland Sunday night. Larry is expected to be
absorbed by a larger extratropical low east of Greenland by Monday.
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.

Tropical Depression Mindy is centered near 32.0N 78.3W at
09/2100 UTC or 100 nm ESE of Charleston South Carolina moving
ENE at 20 kt. Estimated minimum central pressure is 1005 mb.
Maximum sustained wind speed is 30 kt with gusts to 40 kt.
Satellite imagery shows scattered moderate convection is noted
NNE of the center, along the coast of S and N Carolinas. Seas are
from 7 to 8 ft off the Georgia and NE Florida coasts. The
depression is moving toward the east-northeast and this motion is
expected to continue through tonight, followed by a decrease in
forward speed on Friday. Gradual weakening is expected, and Mindy
is forecast to become a remnant low on Friday. 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 31W from 20N southward and
moving W near 15 kt. Scattered showers are noted in the vicinity
of the wave axis.

Another Atlantic tropical wave is along 46W from 19N southward
and moving W at 10 to 15 kt. A 1014 mb low is observed with this
wave near 12N43W. Scattered moderate convection is seen from 07N
to 17N between 41W and 46W.

A Caribbean tropical wave is near 69W from 15N southward across
N Venezuela and SE Colombia, and moving W near 15 kt. The wave is
mainly monitored through the 700 mb trough diagnostics and the
700 mb rawindsonde observations. Scattered showers and isolated
thunderstorms are occurring over S Venezuela.

...MONSOON TROUGH/ITCZ...

A monsoon trough passes through the Gambia coast near 13N16W to
12N31W. The ITCZ continues from 12N31W to 14N41W, then resumes
from 08N44W. Scattered moderate to isolated strong convection
is noted south of the monsoon trough along the coast of Africa
from Guinea-Bissau to the coast of Sierra Leon. Scattered
moderate convection is noted 08N to 18N between 39W to 41W and
between 44W to 47W.

...GULF OF MEXICO...

A surface trough runs northeastward from 22N95W to 26N94W across
the W Gulf. Aided by a mid to upper-level trough in the vicinity,
scattered showers and thunderstorms are flaring up over much of
the Gulf, except waters off the N Mexico coast. Moderate to
locally fresh winds and seas at 3 to 5 ft are evident at the NE
Gulf near the Florida Big Bend coast. Light to gentle winds and
seas at 2 to 3 ft prevail across the rest of the Gulf.

For the forecast, Tropical Depression Mindy is over the Atlantic
waters E of the coast of Georgia. The northern portion of a
tropical wave over northeastern Honduras and the western Caribbean
Sea is forecast to emerge over the southern Bay of Campeche on
Saturday. Environmental conditions are expected to be conducive to
support some gradual development of the system before it moves
over mainland Mexico early next week. This could bring an increase
in winds and seas across the Gulf waters during the upcoming weekend.

...CARIBBEAN SEA...

Convergent trade winds are coupling with divergent flow aloft to
trigger scattered showers and thunderstorms over the NW basin,
including the coast of the Yucatan Peninsula and Honduras. The
E end of the E Pacific monsoon trough is producing similar
conditions at the SW basin, including the coast of Nicaragua,
Costa Rica and Panama.

Due to weaker pressure gradient between the mid-Atlantic ridge and
the lower pressure over Colombia, mainly gentle to moderate trades
and seas at 3 to 5 ft are present across much of the basin.
Locally fresh winds and seas up to 6 ft are possible in stronger
thunderstorms.

For the forecast, as Larry continues to move 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 and
in the Gulf of Venezuela, mainly during the nights.

...ATLANTIC OCEAN...

Please see the Special Features section above for details on
Major Hurricane Larry near Bermuda and Tropical Depression Mindy
just off the coast of S Carolina.

Convergent moderate SW to W winds SW and S of Tropical Depression
Mindy are causing scattered showers and isolated thunderstorms
across N and central Florida, and over NW and central Bahamas. A
pronounced upper-level trough S of the Azores near 30N29W is
producing scattered moderate convection N of 25N between 20W and
30W. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections
for additional convection across the Atlantic Basin.

Larger swells traveling farther away from Larry are generating
seas of 5 to 8 ft N of 23N between 69W and the Florida-Georgia
coast, including the Bahamas. Similar seas are also found from 21N
to 25N between 56W and 69W, and N of 24N between 48W and 53W. For
the remainder of the basin, seas range from 4 to 6 ft. Outside
the influence of Larry, light to gentle winds are present from the
N coast of the Greater Antilles to beyond 31N between 67W and
77W. Gentle to moderate NE trades are dominating N of 10N between
the African coast and 53W/Windward Islands. Light to gentle S to
SW winds prevail S of 10N.

For the forecast, Tropical Depression Mindy near 32.0N 78.3W 1005 mb
at 5 PM EDT moving ENE at 20 kt. Maximum sustained winds 30 kt gusts
40 kt. Mindy will move to 32.9N 74.9W Fri morning, become post-
tropical and move to 33.8N 71.2W Fri afternoon, and dissipate Sat
morning. Mindy is causing a brief period of fresh to strong SW
to W winds N of 29N and W of 78W. Swells generated by Hurricane
Larry will continue to propagate across the waters E of the
Bahamas tonight and Fri. Seas will then subside into the weekend.

$$
Torres/Delgado
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