[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100004
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 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 1800 UTC surface analysis and satellite imagery through
2345 UTC.

...TROPICAL WAVES...

A central Atlantic tropical wave has its axis along 42W from 06N
to 19N, moving westward at about 20 kt. Scattered moderate
convection is on either side of the wave from 09N to 16N between
36W-50W. Latest scatterometer data showed fresh northeast-east
winds in the vicinity of the tropical wave.

A tropical wave has entered the eastern Caribbean Sea. It has
its axis along 61W/62W from 09N 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. It is moving westward about 15
kt. Only isolated showers are seen from 12N to 16N between
69W-75W.

The northern part of a tropical wave is analyzed in the western
Bay of Campeche near 96W and south of 21N. It is moving westward
at 10 kt. Isolated showers and thunderstorms are within 60 nm
either side of this portion of the wave. Scattered moderate
convection is occurring in the W Bay of Campeche, south of 22N.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis enters the Atlantic through the coast of
Senegal near 14N17W. It extends southwestward to near 11N20W,
where it transitions to the ITCZ and continues to 11N30W to
10N38W. The ITCZ resumes at 08N45W and continues to the coast of
Guyana near 07N58W. Aside from convection mentioned above under
Tropical Waves, scattered moderate convection is within 120 nm
south of the ITCZ between 35W-38W, and north of the ITCZ from 09N
to 12N between 50W-60W. This activity trails the tropical wave
that is in the eastern Caribbean Sea.

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 as depicted in a partial ASCAT data pass and as
confirmed by the buoys across the Gulf. Seas throughout are 2-4
ft, except for slightly higher seas of 3-5 ft in the central and
west-central Gulf zones.

Scattered to numerous showers and thunderstorms, some on the
strong side producing frequent lightning and locally strong
winds and seas, are moving east-southeastward over the far
northeastern Gulf. This activity is ahead of an upper-level
shortwave trough. It spreads well inland northern Florida, the
Florida panhandle, Alabama, Mississippi and Louisiana.

For the forecast, the weak high pressure ridge will continue to
dominate the Gulf waters while a trough develops 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 broad central
Atlantic high pressure and relatively lower pressure found in
Colombia where the climatological low is located. Trade winds to
near gale-force are expected within 90 nm of Colombia tonight.
Seas with the fresh to strong trade winds, and with the expected
winds to near gale-force are 6-9 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.

An area of Saharan Dust (also referred to as the Saharan Air
Layer) is approaching the Lesser Antilles.

Scattered showers and few thunderstorms are in the southwestern
Caribbean south of 12N and west of 75W to the coasts of Costa
Rica and Panama.

For the forecast, the tropical wave moving across the central
Caribbean and a new wave entering the E basin today will support
fresh to strong winds and rough seas in this region of the basin
through Tue evening. Fresh to locally strong winds will pulse in
the Gulf of Honduras at night through Tue, then mainly moderate
to fresh winds will prevail through Fri night. Generally
moderate to fresh winds will persist in the eastern and
southwestern sections of the basin through the end of the
upcoming week. Looking ahead, yet another tropical wave is
forecast to bring an increase in winds and seas across the NE
Caribbean Tue night into Wed. The wave will move across Puerto
Rico through late Wed and across Hispaniola Wed night into Thu.
This will induce fresh to strong northeast winds along and in
the Windward Passage Wed night.

For the forecast, the tropical waves moving across Caribbean will
support fresh to strong winds and rough seas in this region of
the basin through Tue evening. Fresh to locally strong winds will
pulse in the Gulf of Honduras at night through Tue, then mainly
moderate to fresh winds will prevail through Thu night.
Generally, moderate to fresh winds will persist in the eastern
and southwestern sections of the basin for the next few days.
Looking ahead, a new tropical wave is forecast to bring an
increase in winds and seas across the northeastern Caribbean Tue
night into Wed. The wave will move across Puerto Rico through
late Wed and across Hispaniola Wed night into Thu. Its associated
gradient will induce fresh to strong northeast winds along the
Windward Passage during this period.

ATLANTIC OCEAN...

A 1025 mb high pressure centered is analyzed near 29N38W, and a
1026 mb high is located near 32N33W. In general, broad high
pressure covers the Atlantic north of 20N and east of 70W. West
of 70W, the high pressure becomes a ridge 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 28N
between 63W-75W. 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. This activity
contains frequent lightning and may be accompanied by locally
higher winds and seas.

An area of Saharan Dust (also referred to as the Saharan Air
Layer), typical for this time of year, is approaching the Lesser
Antilles.

An upper-level low is identified on water vapor imagery to be
near 26N52W. Last GOES-E visible imagery shows high clouds
rotating cyclonically from 21N-29N and between 50W-55W.

For the forecast W of 55W, surface high pressure and associated
ridging will remain in place over the southwestern N Atlantic
waters through Fri night, while a trough moves across the
Carolinas and Georgia adjacent waters through mid-week. The
pressure gradient between these two features will support
moderate to fresh southwest winds north of about 27N, increasing
briefly to fresh to strong speeds through Mon mainly across the
waters N of 29N between 65W-75W. Moderate to locally fresh trade
winds are expected south of 22N, occasionally pulsing to 25 kt
off Hispaniola through Fri night. Light to gentle winds will
persist elsewhere along the ridge axis or to the east of the
Bahamas.

$$
Aguirre
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