[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100651
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0605 UTC Mon Jul 10 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 0000 UTC surface analysis and satellite imagery through
0500 UTC.

...TROPICAL WAVES...

An Atlantic tropical wave has its axis along 44W from 06N to 19N,
moving westward at about 20 kt. A brought area of scattered
moderate convection is seen on either side of the wave from 09N to
18N between 38W-50W. Latest scatterometer data showed fresh
northeast- east winds in the vicinity of the tropical wave.

A tropical wave in the eastern Caribbean Sea has its axis along
63W from the coast of Carupano Venezuela to 19N, and is moving
westward at 15-20 kt. No significant convection is noted at this
time.

A central Caribbean tropical wave has its axis extending from
the southeastern Bahamas to across western Haiti, and continues
to inland Colombia near 08N75W. This wave is moving westward
at about 15 kt. Scattered to isolated strong convection is seen
over Haiti, on both sides of the wave axis.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic through the coast of
Senegal near 14N17W. It extends southwestward to near 08N25W,
where it transitions to the ITCZ and continues to 08N32W to
10N42W. The ITCZ resumes at 11N45W and continues to the coast of
Guyana near 08N58W. Aside from convection mentioned above under
the Tropical Waves section
, scattered moderate convection is
within 120 nm south of the ITCZ between 29W-35W, and north of the
ITCZ from 09N to 15N between 54W to 59W.

GULF OF MEXICO...

Weak Atlantic high pressure ridging stretches southwestward
across South Florida, the Florida Keys and the Straits of Florida
to the southeastern Gulf waters. Its associated gradient is
allowing for generally light to gentle anticyclonic flow across
the basin, with seas 2-4 ft.

Scattered to numerous showers and thunderstorms, some on the
strong side are producing frequent lightning and locally strong
winds and seas. This activity is moving east-southeastward over
the far northeastern Gulf. This activity is ahead of an upper-
level shortwave trough and spreads well inland northern Florida,
the Florida Panhandle, Alabama, Mississippi and Louisiana. Another
area of scattered to numerous showers and thunderstorms is seen
in the Campeche Bay in association with the interaction of a
surface trough and an eastern Pacific tropical wave.

For the forecast, a ridge will continue to dominate the Gulf
waters while a trough will develop over the Yucatan Peninsula each
evening and move offshore. Under this weather pattern, moderate
to fresh winds will pulse north and west of the Yucatan peninsula
during the late afternoon and evening hours. Elsewhere, gentle to
moderate winds and slight seas will prevail.

CARIBBEAN SEA...

Please see the Tropical Waves section above for more details on
a couple of tropical waves that are moving through the basin.

Fresh to strong trade winds are in the south-central Caribbean
as a result of the pressure gradient between a broad central
Atlantic high pressure and relatively lower pressure found in
Colombia, where the climatological low is located. Resent
data from the scatterometer shows northeast to east strong to
near gale-force winds right of the coast of Colombia. Within this
area seas are 6 to 9 ft. Fresh trade winds are elsewhere in the
central Caribbean along with seas of 5-7 ft. In the eastern and
western Caribbean, trade winds are gentle to moderate along with
seas of 3-6 ft.

GOES 16 Saharan Air Layer Tracking Products is depicting an area
of Saharan Dust in the eastern Caribbean and moving west. This
area of dust will move over Puerto Rico and the U.S Virgin Island
this morning. Across the area affected by this, expect lower
dewpoint temperatures and haze skies.

For the forecast, fresh to strong winds and rough seas are
expected over the central Caribbean through at least Tue. Fresh to
locally strong winds will pulse in the Gulf of Honduras at night
through Tue night, then mainly moderate to fresh winds prevail.
Generally moderate winds and seas will persist elsewhere. Looking
ahead, a tropical wave is forecast to bring an increase in winds
and seas across the waters E of the Leeward Islands on Tue, and
over the NE Caribbean on Wed. Fresh to strong NE winds are
expected in the Windward Passage ahead of the wave axis by Wed
night.

ATLANTIC OCEAN...

A 1026 surface high pressure is analyzed near 36N25W, and a 1026
mb high is located near 32N32W. In general, broad high pressure
covers the Atlantic north of 20N and east of 70W. West of 70W, the
high pressure becomes a ridges axis that stretches southwestward
to South Florida, the Florida Keys and the Straits of Florida.
South of 20N, the gradient is allowing for moderate to fresh trade
winds along with seas of 6-8 ft. North of 20N, the gradient
supports gentle to moderate anticyclonic winds along with seas of
3-6 ft.

Scattered showers and thunderstorms are occurring north of 29N
between 61W-71W. This activity is shifting eastward as it is
being sustained by an upper-level trough that extends from
offshore the eastern U.S seaboard, southwestward to the NW
Bahamas.

Scattered to numerous showers and thunderstorms are pushing
offshore central and northern Florida to near 79W in association
with a surface trough. This activity contains frequent lightning
and may be accompanied by locally higher winds and seas.

An upper-level low is identified on water vapor imagery near
26N52W. Last GOES-E visible imagery shows high clouds rotating
cyclonically from 22N to 28N and between 49W-55W

An area of Saharan Dust (also referred to as the Saharan Air
Layer), typical for this time of year, is moving throughout the
Atlantic Ocean as depicted by GOES 16 Saharan Air Layer Tracking
Products. While another Saharan Air Layer outbreak seems to be on
going. Therefore, expect patches of dust through the basin with
lower dewpoint temperatures and haze skies.

A cluster of showers and thunderstorms are seen exiting the coast
of Guinea. This convection may be associated with the next
tropical wave.

For the forecast W of 55W, a ridge will remain in place while a
trough persist off the Carolina and Georgia coasts. The pressure
gradient between these two features will support moderate to fresh
SW winds north of 27N through Tue. A developing low pressure just
N of the forecast region could bring increasing winds over the NE
waters Tue night into Wed. The northern end of a tropical wave is
forecast to impact the waters north of the Leeward Islands and
Puerto Rico on Wed, and north of Hispaniola, including approaches
to the Windward Passage by Wed night. Light to gentle winds will
persist elsewhere along the ridge axis.

$$
KRV
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