[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101131
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 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 0600 UTC surface analysis and satellite imagery through
1000 UTC.

...TROPICAL WAVES...

A tropical wave has its axis along 46W from 06N to 19N, moving
westward at about 20 kt. Abundant cloudiness, with scattered
showers and thunderstorms are associated with the wave. Recent
scatterometer data indicate fresh winds in the vicinity of the
tropical wave, mainly N of 13N while an altimeter pass shows seas
of 7 to 9 ft on the E side of the wave axis.

A tropical wave in the eastern Caribbean Sea has its axis along
67W, extending from Puerto Rico to the coast of central Venezuela.
The wave is moving westward at 15-20 kt. A few showers are near
the wave axis.

Another tropical wave is moving westward across the Caribbean
Sea. Its axis is along 77W/78W and extends from eastern Cuba to
eastern Panama. The wave is generating isolated to scattered
showers and thunderstorms over eastern Cuba and near the Cayman
Islands.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of Senegal
near 14N17W, then continues SW to near 08N25W. The ITCZ extends
from 08N25W to 06N35W to 10N44W to 10N60W. A large cluster of
moderate to strong convection is moving off the W coast of Africa
and covers the waters from 07N to 11N between 15W and 20W. This
convective activity could be associated with the next tropical
wave. Another cluster of moderate to isolated strong convection
is noted from 06N to 09N between 20W and 23W. Scattered moderate
convection is within about 210 nm S of the ITCZ axis between 30W
and 35W.

GULF OF MEXICO...

The Atlantic ridge extends 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 eastern half of the Gulf waters where
seas are in the 1 to 3 ft range. Moderate to locally fresh SE
winds are noted N of the Yucatan Peninsula likely associated with
the thermal trough that develops there. Moderate to locally fresh
Se to S winds are observed over the western Gulf with seas of 2 to
4 ft. Scattered showers and thunderstorms are over the NE Gulf.
This activity is ahead of an upper-level shortwave trough.
Another area of scattered 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
anticyclonic flow 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 the Atlantic high
pressure and relatively lower pressure found in Colombia, where
the climatological low is located. Seas are 7 to 10 ft within
these winds. Fresh trade winds are elsewhere in the central
Caribbean along with seas of 5 to 7 ft. In the eastern and
western Caribbean, trade winds are gentle to moderate along with
seas of 3 to 6 ft. The Saharan Air Layer tracking product from
CIMSS shows African dust reaching the eastern Caribbean, including
Puerto Rico.

Scattered showers and thunderstorms are in the southwestern Caribbean
affecting parts of Nicaragua and near the coast of western Panama.
Similar convective activity is impacting the Windward Islands and
regional waters.

For the forecast, fresh to strong winds and rough seas are expected
over the central Caribbean through at least Tue night. 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 1025 mb high pressure centered is analyzed SW of the Azores
near 32N31W. The associated ridge extends westward reaching the
Bahamas and South Florida. South of 20N, the pressure gradient is
allowing for moderate to fresh trade winds along with seas of 6
to 8 ft. North of 20N, the gradient supports gentle to moderate
anticyclonic winds along with seas of 3 to 6 ft. Light and
variable winds are along the ridge axis.

An upper-level low located near 26N52W is generating isolated
showers and thunderstorms. Scattered showers and thunderstorms are
near 31N70W. This activity is shifting eastward ahead of an
upper-level trough that extends from offshore the eastern U.S
seaboard, southwestward to the NW Bahamas.

An area of Saharan Dust, typical for this time of year, is moving
throughout the Atlantic Ocean as depicted by the Saharan Air Layer
Tracking Products from CIMSS. Therefore, expect patches of dust
through the basin with lower dewpoint temperatures and haze skies.

Looking ahead, an area of low pressure is expected to form in a
couple of days several hundred miles to the east-northeast of
Bermuda. This system is then forecast to interact with an upper-
level trough, and could acquire some subtropical or tropical
characteristics during the middle to latter part of this week
while it pivots southeastward to northeastward. By the weekend,
the low is expected to turn northward bringing the system over
cooler waters, likely limiting additional development. Please,
refer to the latest Tropical Weather Outlook at
www.hurricanes.gov for more details.

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
located 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.

$$
GR
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