[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 061001
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Mon Sep 6 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

...SPECIAL FEATURES...

Hurricane Larry is centered near 21.6N 52.4W at 06/0900 UTC,
moving NW at 10 kt. Estimated minimum central pressure is 956 mb.
Maximum sustained wind speed is 105 kt with gusts to 130 kt. The
eye diameter is 50 nm on IR satellite imagery. Numerous moderate
to strong convection is within 180 nm of the center. Seas of 12 ft
or higher extend outward 300 nm from the center in the N
semicircle, 240 nm SE quadrant, and 270 nm SW quadrant, with seas
peaking at 45 ft. On the forecast track, a northwest motion with a
slight decrease in forward speed is expected during the next few
days. Little change in strength is forecast during the next day or
so, followed by very gradual weakening. Swells generated by Larry
are reaching the Lesser Antilles and are expected to spread
westward to portions of the Greater Antilles, the Bahamas, and
Bermuda later today and Tuesday. Significant swells should reach
the east coast of the United States and Atlantic Canada by
midweek. These swells are likely to cause life-threatening surf
and rip currents. 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 WAVES...

An eastern Atlantic Ocean tropical wave has an axis along 26W,
from 19N southward, moving W around 15 kt. Scattered moderate
convection is noted from 06N to 09N between 20W and 30W.

A central Atlantic Ocean tropical wave has an axis along 42W, from
17N southward, moving W around 10 kt. The wave is situated at the
leading edge of a Saharan dust plume, so no significant convection
is associated with this wave.

A Caribbean Sea tropical wave has an axis along 80W, from Jamaica
to central Panama, moving W at 10 kt. Scattered moderate
convection is within 150 nm either side of the wave axis, mainly S
of 14N.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends into the Atlantic Ocean off the coast
of northern Senegal near 16N17W to 06N32W. The ITCZ extends from
06N32W to 05N39W, then continues W of a tropical wave from
04N42W to 06N52W to 09N61W. Aside from the convection mentioned in
the Tropical Waves section above, scattered moderate convection is
noted from 03N to 06N between 30W and 35W and from 04N to 08N
between 46W and 51W.

GULF OF MEXICO...

A weak 1011 mb low along a surface trough is analyzed just off
the west coast of the Yucatan Peninsula near 21N91W. The surface
trough extends NNE from the low to near 24N89W. Locally fresh
SE winds are occurring on the NE side of the low, just N of the
Yucatan Peninsula. Scattered moderate convection is noted over the
peninsula, extending northward to 25N. Numerous moderate to
isolated strong convection is occurring within 90 nm offshore of
Veracruz, Mexico.

Generally modest surface ridging dominates the rest of the basin,
with a surface high pressure of 1016 mb centered over the Florida
Straits. This is leading to light to gentle winds and seas of 3
ft or less.

For the forecast, the low pressure off the coast of the Yucatan
Peninsula is forecast to move N or NE over the central and NE Gulf
of Mexico over next few days, likely reaching the northern Gulf
coast by mid-week. Upper- level winds are currently unfavorable
for tropical development, but could become somewhat conducive for
formation before it reaches the coast. Aside from this low
pressure, high pressure will bring light to gentle winds and
slight seas into mid-week.

CARIBBEAN SEA...

See the Tropical Waves section above for details on the tropical
wave moving into the western Caribbean.

Scattered moderate convection is noted over eastern Cuba and
adjacent waters, while activity previously over the northwest
Caribbean has diminished early this morning. Generally dry air and
high pressure dominate the rest of the basin, with moderate to
fresh trades ongoing. Seas are generally 3 to 5 ft, except 5 to 7
ft offshore Colombia. Swell from distance hurricane Larry is
beginning to enter Atlantic passages off the Leeward Islands,
where seas of 5 to 7 ft are occurring.

For the forecast, major Hurricane Larry will remain well to the
northeast of the Leeward Islands today, then move farther north of
the area through mid week. Associated rough seas east of Leeward
Islands and Atlantic entrances will persist into mid week.
Elsewhere, gentle to moderate trade winds will persist, pulsing to
fresh winds off Colombia mainly at night.

ATLANTIC OCEAN...

Please see the Special Features section for details on Category 3
Hurricane Larry.

Mid and upper level divergence is leading to scattered moderate
to isolated strong convection over the Bahamas, otherwise
generally high pressure dominates the basin outside of Major
Hurricane Larry. A 1018 mb high pressure is centered near 27N62W,
and a 1019 mb high pressure center is noted near 27N40W. Thus,
generally outside of Larry, light to gentle wind prevails with
seas of 3 to 6 ft. To the S and E of Larry, generally S of 20N and
E of 50W, moderate to fresh NE trades prevail. Also, a weakening
cold front is noted in the northeast basin, from 30N18W to 27N27W
to 30N37W. No convection is associated with this front, and winds
north of the boundary are N and gentle to moderate.

For the forecast, Major Hurricane Larry will move to 22.6N 53.6W
this afternoon, 23.9N 54.9W Tue morning, 25.3N 56.2W Tue
afternoon, 26.8N 57.5W Wed morning, 28.5N 59.0W Wed afternoon, and
30.6N 60.6W Thu morning. Larry will change little in intensity as
it moves to the northeast of Bermuda early Fri. Large swell and
rough seas generated by Larry will continue to propagate across
waters northeast of the Leeward Islands and spread west of 65W
today, the perhaps reach 70W by mid week.

$$
KONARIK
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