982
AXNT20 KNHC 201016
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Sat Jul 20 2024

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
1100 UTC.

...TROPICAL WAVES...

An eastern Atlantic tropical wave is along 28W/29W, south of 20N,
moving westward at 10 to 15 kt. A few showers are seen near the
trough axis.

A tropical wave is moving westward across the central Caribbean at
20 to 25 kt. Its axis is along 74W/75W extending from the Windward
Passage to northern Colombia. The wave is helping to induce scattered
to numerous showers with embedded thunderstorms over Hispaniola
and regional waters as well as across the Windward Passage and
the waters between eastern Cuba and Jamaica. These storms may
produce heavy downpours, lightning and gusty winds.

A tropical wave is over the Yucatan Peninsula and Guatemala
extending southward into the EPAC region moving westward at 20
kt. The wave, combined with an upper-level low over the south-
central Gulf of Mexico, is supporting scattered to numerous
showers and thunderstorms over parts of Belize and Guatemala.
Gusty winds are possible near the stronger storms.

...MONSOON TROUGH/ITCZ...

The monsoon trough enters the Atlantic through the coast of Senegal
near 15N16W and continues westward to 10N30W and to 07N55W. A large
area of Saharan dust extends across the Atlantic, and is suppressing
any significant convection at this time.

...GULF OF MEXICO...

Scattered showers and thunderstorms are noted over portions of the
Gulf region associated with an upper-level cyclonic circulation
located over the south-central Gulf. At the surface, the Atlantic
ridge extends westward into the central Gulf, supporting gentle to
moderate winds S of 25N, and light to gentle winds N of 25N. Seas
are in the 1 to 3 ft range.

For the forecast, a ridge will remain in place across the Gulf
waters over the next several days. It will support gentle to
locally moderate E to SE winds and slight seas. Pulsing moderate
to fresh winds are expected near and to the NW of the Yucatan
Peninsula during the evening and night hours due to local effects.

...CARIBBEAN SEA...

A tropical wave is moving westward across the central Caribbean
Sea. Please, see the Tropical Waves section above for more details.

Recent satellite derived wind data indicate moderate to fresh trade
winds with seas of 4 to 6 ft over the east and central Caribbean.
Gentle to moderate winds and seas of 3 to 5 ft are evident over
the NW Caribbean while light and variable winds are noted offshore
Costa Rica and Panama due to the presence of the EPAC monsoon trough.
Seas there are 2 to 3 ft. A band-like of showers and thunderstorms
extends from the Gulf of Honduras across NE Honduras and northern
Nicaragua into the SW Caribbean. Low-topped trade wind showers
are seen elsewhere outside the influence of the tropical wave.

For the forecast, as previously mentioned, a tropical wave is
moving across the central Caribbean. Expect increasing winds and
building seas in the wake of the wave axis today through Mon. The
forecast calls for fresh to strong winds and seas of 8 to 10 ft.
The trade winds and associated seas will diminish slightly on Tue,
then increase again across the east and central Caribbean Tue
night into Wed as the Atlantic high pressure strengthens some.

...ATLANTIC OCEAN...

An area of showers and thunderstorms is just N of Hispaniola to
about 24N. This convective active is related to the northern end
of a tropical wave moving across the central Caribbean. The
pressure gradient between the Atlantic high pressure and the
northern end of the wave is resulting in an area of fresh to
locally strong E winds offshore Puerto Rico and Hispaniola,
particularly from 20N to 22N between 67W and 74W, including
approaches to the Windward Passage. Scattered showers and
thunderstorms are also noted across the Florida coastal waters.
As it is normal for this time of the year, Saharan dust dominates
most of the Atlantic waters E of 62W/63W, including the Lesser
Antilles.

Of note, SAL activity usually ramps up in mid-June, peaks from
late June to mid-August, and begins to rapidly subside after mid-
August. During peak period, individual SAL outbreaks reach father
to the west (as far west as Florida, Central America and even
Texas) and cover a vast areas of the Atlantic.

A 1028 mb high pressure located ENE of Bermuda near 33N56W dominates
the Atlantic forecast waters. Under the influence of this system,
mainly moderate to fresh winds and 5 to 7 ft seas prevail S of 26N
with gentle to moderate winds and seas of 3 to 5 ft N of 26N.
Winds increase to fresh to strong speeds between the Canary Islands
and off the northwest coast of Africa. A surface trough runs from
30N35W to 20N46W. Mostly low level clouds with possible showers
are near the trough axis.

For the forecast west of 55W, the Bermuda-Azores high will continue
to dominate the Atlantic forecast waters. The associated ridge
will slowly lift N to near 30N Mon through midweek. The related
pressure gradient will support moderate to fresh easterly winds
south of 26N, with winds pulsing to strong during the late
afternoons and evenings off the northern coast of Hispaniola into
next week. The northern portion of a tropical wave will move
through the waters south of 24N through Mon accompanied by scattered
to numerous showers and thunderstorms, some of which may produce
strong gusty winds and rough seas.

Tropical cyclone formation is not expected during the next 7 days.
Please, see the latest NHC Tropical Weather Outlook at
www.hurricane.gov for more details.

$$
GR