[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 192353
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0005 UTC Tue Jul 20 2021

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
2300 UTC.

...TROPICAL WAVES...

A tropical wave is likely along 22W/23W from 15N southward. The
Hovmoller Diagram shows the westward propagation of the wave
that should be added to the next surface analysis at 0000 UTC.
The Tropical Wave Diagnostics and the TPW also support the
presence of the wave. Scattered moderate to isolated strong
convection is from 09N- 12N between 22W-26W.

A tropical is across the tropical Atlantic along 42W from 20N
southward and moving W near 10 kt. No significant convection is
associated with this wave that is surrounding by African dust.

A tropical wave is over the western Caribbean along 81W, and
extends from the Cayman Islands southward across Panama, and
moving W at 15 to 20 kt. Scattered to numerous showers and
thunderstorms are ahead of the wave axis affecting parts of
Honduras and Nicaragua.

A tropical wave is over the Bay of Campeche along 93W/94W and
extends southward into the eastern Pacific region. Scattered
showers are noted near the northern end of the wave axis.

...MONSOON TROUGH/ITCZ...

A monsoon trough enters the Atlantic Ocean through Senegal near
14N17W and extends to 11N30W to 07N44W. The ITCZ then continues
from 07N44W to northern Guyana. Aside from convection related to
the tropical waves, no significant convection is noted.

...GULF OF MEXICO...

A tropical wave is over the Bay of Campeche. Please refer to the
Tropical Wave section above for details.

A ridge dominates the Gulf waters with a 1019 mb high pressure
located over the NE Gulf. This system is producing mainly a light
to gentle anticyclonic flow across the basin based on the most
recent scatterometer data. Seas are generally 1-3 ft across the
entire Gulf. The northern portion of a tropical wave currently
located over the Caribbean Sea along 81W is analyzed as a trough
over the NW Bahamas and central Cuba. This system is forecast to
approach South Florida late tonight into Tuesday increasing the
likelihood of showers and thunderstorms.

For the forecast, as it is normal for this time of the year,
the Bermuda-Azores High extends a ridge across Florida into the
Gulf region. A high pressure cell sometimes develops over the NE
Gulf. This system will continue to dominate the Gulf waters with
gentle to moderate winds the rest of the work-week. The exception
will be moderate to fresh NE-E winds to the west of the Yucatan
Peninsula Wed night through Fri night due to local effects induced
by a thermal trough.

...CARIBBEAN SEA...

A tropical wave is over the western Caribbean. Please refer to
the Tropical Wave section above for details.

Showers and thunderstorms have flared up across most of Cuba and
Hispaniola. An upper-level trough, that crosses the SE Bahamas
and eastern Cuba into the NW Caribbean, combined with the northern
extent of the aforementioned tropical wave is likely causing
this convective activity.

Fresh to strong trades are seen over the south-central Caribbean
and near the tropical wave located along 81W. Moderate trades
are noted over the eastern Caribbean with gentle to moderate
winds over the NW part of the basin. Seas are in the 6-9 ft
range over the south-central Caribbean, 4-6 ft over the eastern
Caribbean, and 2-5 ft over the NW Caribbean.

For the forecast, high pressure N of the Caribbean Sea combined
with the Colombian low will support near gale force winds within
about 90 nm of the coast of Colombia, and in the Gulf of Venezuela
mainly during the overnight and early morning hours through at
least Thu. In addition, expect an increase in areal coverage of
the fresh to strong wind reaching as far north as Hispaniola
adjacent waters. Fresh to locally strong easterly winds are
expected in the Gulf of Honduras through Thu night.

...ATLANTIC OCEAN...

A pair of tropical waves are between the west coast of Africa and
the Lesser Antilles. Please refer to the Tropical Wave section
above for details.

The Bermuda-Azores High dominates the Atlantic forecast waters
with a couple of centers, one of 1026 mb located E of Bermuda
near 32N75W, and the second one near 31N36W. Mainly patches of
low level clouds are seen over the ocean. Moderate to fresh NE
winds are noted around the southern periphery of the ridge, and
near the coast of Morocco and Mauritania. Seas are in the 5-7 ft
range within these winds.

For the forecast W of 65W, high pressure will be in control of
the weather pattern across the region. Fresh to strong easterly
winds will pulse in the late afternoon and evening hours just off
north of Hispaniola, including the approach to the Windward
passage for the next several days.

$$
GR
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