[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201750
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Jul 20 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 34.3N 42.2W at 20/1200 UTC.
or about 739 nm WSW of the Azores. It is moving west-northwest at
6 kt. The estimated minimum central pressure is 1002 mb. Maximum
sustained winds are 45 kt with gusts to 55 kt. Numerous moderate
convection is present within 150 nm northeast to east of the
center of Don, and within 30 nm southwest of Don. Don is forecast
to continue its current motion, with an increase in forward speeds
during the next couple of days. Don is later expected to turn
northward over the weekend. Slight strengthening is expected
during the next day or so, followed by little change in strength
through Saturday.

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 far eastern Atlantic tropical wave is west of the Cabo Verde
Islands with its axis stretching from near 19N28W to 05N31W. It
is moving westward around 10 kt. Scattered moderate convection is
within 60 nm east of the wave from 07N to 10N.

An eastern Caribbean Sea tropical wave has its axis near 71W
south of 18N, just south of Dominican Republic to inland
Venezuela. It is moving westward at about 15 kt. No significant
convection is seen near this wave based on the latest analysis.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic near Bissau
west Africa, and continues southwestward to 12N30W and to 07N48W.
Aside from convection associated to the far eastern Atlantic
tropical wave, scattered moderate to isolated strong convection is
moving off the coast of Africa from 06N to 17N. This convection
may be associated with the next tropical wave. Scattered moderate
convection is within the trough and south of the trough between
33W-41W. In addition, recent scatterometer data revealed
localized fresh southeasterly winds whithin this area.

...GULF OF MEXICO...

A surface trough along the Florida west coast is producing
scattered showers and isolated thunderstorms over the southwestern
near shore and off shore Florida waters. Elsewhere, a weak
surface high pressure is dominating the sensible weather. Moderate
E to SE winds and seas of 3-5 ft are occurring at the central and
eastern Bay of Campeche. Light to gentle winds and seas of 1-2 ft
are present across the north- central and northeastern Gulf.
Gentle to moderate E to SE winds with 2-4 ft seas prevail for the
rest of the Gulf, including the Straits of Florida. Winds and seas
may be higher in areas of convection.

For the forecast, a weak ridge of high pressure will remain in
control of the weather pattern across the Gulf waters through the
forecast period. This will support mainly gentle to moderate
winds, except over the Bay of Campeche where winds will be
enhanced by a thermal trough coming off the Yucatan Peninsula
during the night hours.

...CARIBBEAN SEA...

The GOES-16 Saharan Air Layer Tracking product is showing an area
of Saharan dust moving west across the Atlantic Ocean and into the
eastern Carribbean. This dust is already moving across the Lesser
Antilles, Puerto Rico, and the Hispaniola. Therefore, expect
adry and hazy conditions with patches of lower visibility.

Convergent ESE trade winds in combination with an mid to upper
level disturbance are producing scattered showers and isolated
thunderstorms near Jamaica and south of Cuba. Refer to the
Tropical Waves section above for more details about additional
convection in the basin. A recent scatterometer pass confirmed
that the tight pressure gradient between the Bermuda High and
lower pressure at northwestern Colombia is producing strong with
locally near- gale E to NE winds and seas of 7-11 ft, between
Haiti and Colombia. Fresh to strong E winds and 4-7 ft seas are
present for the eastern basin. Gentle to moderate NE winds and
seas of 6-10 ft are present in the southwestern basin. North of
Panama and near western Cuba moderate mainly E winds, with seas
2-5 ft.

For the forecast, the aforementioned pressure gradient between
the Bermuda High and lower pressure over Central America/N South
America will maintain fresh to near gale trades across the central
Caribbean through Sat. Winds should diminish down to fresh to
strong Sun and Mon. Fresh to locally strong trades will develop
over the Gulf of Honduras Sat night through Mon.

ATLANTIC OCEAN...

Please see the SPECIAL FEATURES section for the latest information
on Tropical Storm Don.

Low level convergence is producing scattered showers and isolated
thunderstorms south of Bermuda, north of 28N between 62W-68W.
The GOES-16 Saharan Air Layer Tracking product is showing an area
of Saharan dust moving west across the Atlantic Ocean. Hence, the
lack of convection is the central and western Atlantic. Therefore,
expect dry and hazy conditions with patches of lower visibility
within this area. Refer to the Monsoon Trough/ITCZ and Tropical
Waves sections above for additional cnvection in the tropical
Atlantic.

The Bermuda High is supporting light to gentle winds with seas at
3-5 ft across the western Atlantic, except for the area north of
20N between 63W and east coast of Florida where seas are 4-6 ft.
Over the central and eastern Atlantic, surface high pressure
ridging related to a 1023 mb Azores High is maintaining light to
gentle winds and 3-6 ft seas north of 20N between 27W-50W. Near
the Canary Islands, moderate to fresh NNE trades and seas of 4 to
6 ft dominate north of 21N between the Africa coast and 28W. Across
the tropical Atlantic, outside of convection, light to gentle ENE
trades with 4-6 ft seas are seen from 07N to 20N between 48W and
the Lesser Antilles, and from 12N to 20N between 27W-48W. Near the
Cabo Verde Islands, gentle to moderate NE to N winds and seas of
3-5 ft are found from 14N-20N between 20W-27W. Gentle to moderate
with locally fresh southerly and monsoonal westerly winds and 4-6
ft in southerly swell prevail for the remainder of the Atlantic
Basin.

For the forecast west of 55W, the Bermuda High centered near
31N59W this morning will weaken and shift east-southeastward
through the weekend. Fresh to strong trades just north of
Hispaniola and over the Windward Passage will diminish by Fri.
Elsewhere across forecast waters, winds will be moderate or weaker
through Mon.

$$
KRV
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