[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 022237
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
637 PM EDT Wed Sep 2 2020

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 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2200 UTC.

...SPECIAL FEATURES...

Tropical Storm Nana is centered near 17.0N 85.9W at 02/2100 UTC
or 60 nm NE of Isla Roatan Honduras moving W at 13 kt. Estimated
minimum central pressure is 999 mb. Maximum sustained wind speed
is 50 kt with gusts to 60 kt. Seas 12 ft or greater are within
75 nm NE quadrant...30 nm SE quadrant...0 nm SW quadrant...and 60
nm NW quadrant with peak seas near 21 ft. Numerous moderate to
strong convection is noted within 120 nm SW semicircle. Nana will
be moving near but north of the coast of Honduras and the Bay
Islands this evening, and the center should make landfall on the
coast of Belize tonight or early Thu. While Nana has not
strengthened during the past several hours, strengthening is
expected before landfall, and Nana could become a hurricane by the
time the center reaches the coast of Belize. Please read the
latest NHC Public Advisory at
https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/
Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more
details.

Tropical Depression Omar is centered near 36.1N 65.7W at 02/2100
UTC or 230 nm N of Bermuda moving E at 12 kt. Estimated minimum
central pressure is 1005 mb. Maximum sustained wind speed is 30
kt with gusts to 40 kt. Seas 12 ft or greater are within 0 nm N
semicircle...60 nm SE quadrant and 80 nm SW quadrant with peak
seas to 13 ft. A turn toward the east-northeast with some
reduction in forward speed is forecast on Sat. Further weakening
is forecast, and Omar is likely to become a remnant low Sat with
dissipation by Sat night. Please read the latest NHC Public
Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and
Forecast/ Advisory at
https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details.

...TROPICAL WAVES...

A tropical wave, located just off the coast of west Africa along
20W, is producing limited shower activity. The wave is expected
to merge with a disturbance centered a couple of hundred miles
southeast of the Cabo Verde Islands toward the end of the week.
Gradual development of this system is then possible, and a
tropical depression could form over the weekend while it moves
westward over the eastern and central tropical Atlantic Ocean.
This system has a low chance of tropical cyclone formation during
the next 48 hours, and a medium chance during the next five days.
Please see the North Atlantic Tropical Weather Outlook for the
latest updates.

An Atlantic Ocean tropical wave is along 37W from 17N southward,
moving W at 10-15 kt. Scattered moderate convection is from 13N
to 15N between 37W and 39W. Some development of low pressure in
association with this wave is possible this week as it drifts
generally westward over the eastern and central tropical Atlantic
Ocean. This system has a low chance of tropical cyclone formation
during the next five days. Please see the North Atlantic Tropical
Weather Outlook for the latest updates.

An Atlantic Ocean tropical wave is along 48W from 17N southward,
moving W at 10 kt. No significant convection is associated with
the wave at this time.

An Atlantic Ocean tropical wave is along 59W from 20N southward,
moving W at 10-15 kt. Isolated moderate convection is noted from
13N to 15N within 120 nm east of the wave axis.

A Caribbean Sea tropical wave is along 73W from 20N southward,
moving W at 15-20 kt. Scattered moderate convection is noted N of
14N within 180 nm of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough extends off the coast of Mauritania near
19N16W to 12N22W to 1007 mb low pressure near 12.5N36.5N to
11N45W. The ITCZ extends from 11N49W to 10N58W. In addition to the
convection described above, scattered moderate convection is
occurring within 300 nm S of the monsoon trough between 25W and
31W.

GULF OF MEXICO...

A surface ridge extends across the western Atlantic and passes
through central Florida to 1017 mb high pressure over the NE Gulf
near 29N87W. Moderate southerly winds prevail across the Gulf
waters W of 93W, with locally fresh winds possible near the
southern Texas coast. Buoy 42019 has reported wave heights between
6.5-8 ft over the past several hours. Elsewhere, moderate winds
are noted in earlier scatterometer data through the Straits of
Florida. Light to gentle winds prevail near the high pressure over
the NE Gulf.

High pressure over the eastern Gulf will support moderate to
fresh southerly winds over the western Gulf, and light to gentle
breezes over the eastern Gulf through tonight. The high pressure
will lift north of the area later in the week ahead of a trough
entering the eastern Gulf. The trough will dissipate over the
central Gulf by Fri. Looking ahead, a weak front will stall over
the northern Gulf Sat and dissipate through late Sun.

CARIBBEAN SEA...

Please see the Special Features section above for information
about Tropical Storm Nana. Nana will move to 16.8N 87.8W Thu
morning, inland to 16.6N 90.1W Thu afternoon, move inland and
weaken to a tropical depression near 16.4N 92.4W Fri morning,
become a remnant low and move to 16.2N 94.8W Fri afternoon, and
dissipate Sat morning.

Moderate to fresh E winds are occurring south of Hispaniola this
evening, while moderate E winds continue south of Cuba. Seas are
generally 4-6 ft within these enhanced trades. Elsewhere, gentle
to moderate breezes are ongoing N of 15N, with light winds S of
15N over the SW Caribbean. GOES-16 satellite imagery and
lightning data show scattered showers and thunderstorms over
portions of the NW Caribbean this evening.

Moderate to fresh trades will persist over the central Caribbean
in the wake of Nana through Sun with gentle to moderate breezes
elsewhere.

ATLANTIC OCEAN...

A subtropical ridge extends westward from 1019 mb high pressure
near 32N50W toward central Florida. Light to gentle winds prevail
near the ridge axis that crosses the offshore waters along 28N.
South of the ridge, moderate trades are occurring S of 24N W of
60W, with fresh winds north of Hispaniola and near the approach
to the Windward Passage. Seas likely range from 5-7 ft in this
region. Visible GOES-16 imagery from earlier today indicated that
dust associated with the Saharan Air Layer was moving across
portions of the SW Atlantic waters.

Farther east, broad ridging N of 20N is supporting gentle to
moderate trades and 5-7 ft seas over much of the eastern Atlantic.
Fresh to occasionally strong winds and locally higher seas are
found south of the monsoon trough E of 40W.

A ridge extending from the central Atlantic to near Bermuda to
the northern Bahamas will support fresh to locally strong winds
off Hispaniola and the approaches to the Windward Passage tonight
into Thu morning. The ridge will remain along 29N Thu and Fri,
supporting moderate to fresh trades south of 22N.

$$
B Reinhart
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