[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221706
TWDAT

Tropical Weather Discussion NWS National Hurricane Center Miami
FL 1805 UTC Sat Jul 22 2023

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 1200 UTC surface analysis and satellite imagery through
1700 UTC.

...SPECIAL FEATURES...

Tropical Storm Don is centered near 39.1N 50.1W at 22/1500 UTC
or 470 nm SSE of Cape Race Newfoundland moving N at 11 kt.
Estimated minimum central pressure is 995 mb. Maximum sustained
wind speed is 55 kt with gusts to 65 kt. Don's convective
structure has increased in organization this morning. A curved
band has wrapped completely around the center with a ragged eye-
like feature becoming apparent during the past couple of hours.
Earlier microwave imagery also revealed this feature, but the
convection surrounding it was fragmented. A turn to the north is
expected later today, followed by a northeastward motion on
Sunday. Some strengthening is possible today.  However,
weakening is forecast to begin by tonight or Sunday morning, Don
is expected to become a post-tropical cyclone on Sunday or
Sunday night.

Please read the latest HIGH SEAS
FORECAST issued by National Hurricane Center at website
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest
T.S.
Don Forecast/Advisory and Public Advisory at www.hurricanes.gov
for more details.

Central Tropical Atlantic (AL95):
Shower activity associated with a small area of low pressure
located roughly midway between the Cabo Verde Islands and the
Lesser Antilles continues to show signs of organization.
Although environmental conditions are only marginally conducive,
some additional gradual development is anticipated and this
system will likely become a tropical depression by early next
week while it moves westward across the tropical Atlantic.
Interests in the Lesser Antilles should monitor the progress of
this system. The disturbance has a medium chance of development
over the next 48 hours. Refer to the latest Tropical Weather
Outlook at www.hurricanes.gov for more details.

Gale Warning E of 35W:
The strong pressure gradient between a 1029 mb high pressure near
the Azores and lower pressures over NW Africa has induced fresh
to near gale-force northerly winds in the eastern Atlantic,
mainly north of 17N and east of 25W. The strongest winds are
present off the coast of Morocco and Western Sahara and in the
water passages of the Canary Islands. Seas in the affected area
are 6-10 ft. Meteo-France is forecasting frequent gusts to gale
force and rough to very rough seas in the Agadir and Canarias
Marine Zones until 23/0300 UTC. Please read the High Sea
Forecast and Warning at https://wwmiws.wmo.int for more details.

...TROPICAL WAVES...

An eastern Atlantic tropical wave has its axis along 33W from
05N to 19W. It is moving westward at 10-15 kt. No significant
convection is noted in association with this wave.

A eastern Caribbean tropical wave has its axis along 82W and
south of 19N. It is moving westward at 10-15 kt. The interaction
between the wave axis and the eastern Pacific monsoon trough is
producing scattered showers and a few thunderstorms along the
coast of southern Costa Rica and along the coast of northern
Panama.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis reaches the Atlantic through the coast of
Mauritania near 19N16W. It continues southwestward to 11N24W,
then to 13N38W to the SPECIAL FEATURES low pressure near
12.1N41.7W and to 09N46W. Scattered moderate convection is from
04N to 13N and east of 24W to the coast of Africa.

...GULF OF MEXICO...

A trough is over the Yucatan Peninsula from 22N88W to 18N88W.
Scattered showers and isolated thunderstorms are seen east of
the trough. Weak high pressure continues to dominate the Gulf
waters, with the associated gradient resulting in moderate or
weaker winds and 1-3 ft seas.

For the forecast, the aforementioned weak high pressure centered
near the eastern Gulf will remain dominant into early next week.
This will support mainly gentle to moderate winds, except over
the eastern Bay of Campeche where winds will be enhanced by a
thermal trough that will emerge off the Yucatan Peninsula during
the overnight hours.

...CARIBBEAN SEA...

Please see the TROPICAL WAVE section above for convection
in the western Caribbean. The remainder of the basin is under
the influence of a subtropical ridge positioned near the Azores.
Saharan dust covers most of the eastern and central Caribbean,
resulting in drier conditions, above normal temperatures and
reduced visibility.

The pressure gradient between the ridge and lower pressures in NW
South America continue to sustain fresh to strong easterly trade
winds in the south-central Caribbean as seen by a recent
scatterometer. In the remainder of the basin, moderate or weaker
winds prevail. Wave heights are in the 8-10 ft range over the
central Caribbean and much lower in the 2-6 ft range elsewhere.

For the forecast, the pressure gradient between the Bermuda High
and lower pressure over Central America and northern South
America will maintain strong trades across the central Caribbean
through tonight. Winds should diminish slightly to fresh to
strong Sun through Tue night. Fresh to locally strong trades
will develop over the Gulf of Honduras tonight through Mon. Low
pressure, AL95, well east of the region is forecast to move into
Atlantic waters E of the Lesser Antilles early next week,
possibly as a tropical cyclone. Expect increasing wind and seas
over these waters in association with this low pressure system.


...ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section for information on
Tropical Storm Don in the north-central Atlantic, gale winds in
the eastern Atlantic, and INVEST 95L in the central Atlantic.

An upper-level trough north of 20N between 45W-60W  is
producing scattered showers and thunderstorms north of 25N and
between 54W-69W. The rest of the tropical Atlantic is under the
dominance of a 1029 mb subtropical ridge centered near the
Azores. A large outbreak of Saharan dust (SAL) continues to
propagate across the central and eastern Atlantic suppressing
the development of showers and thunderstorms.

Scattered moderate convection, aided by a broad upper-level
trough, is just north of the discussion area west of 74W. This
activity is moving eastward, and should remain quite active
through at least this evening.

The pressure gradient between the aforementioned ridge that
extends into the SW Atlantic and lower pressures over the
eastern United States is leading to moderate southwest to west
winds north of 27N and west of 66W. Seas over these waters are 4-
6 ft. Light variable winds and 2-4 ft seas are noted between the
SE Bahamas, northern Hispaniola and NE Cuba. Elsewhere, west of
55W, light to gentle anticyclonic winds and slight seas prevail.
Over the remainder of the tropical Atlantic moderate or weaker
winds and slight to moderate seas are prevalent.

For the forecast west of 55W, weak high pressure will dominate
into early next week. Fresh trades just north of Hispaniola and
over the Windward Passage will diminish tonight. Elsewhere
across forecast waters, winds will be moderate or weaker into
next week.

$$
KRV
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