[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 171003
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1205 UTC Wed Aug 17 2022

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
0950 UTC.

...TROPICAL WAVES...

A central Atlantic tropical wave has its axis near 43W, south of
20N, moving W at 15 o 20 knots. Isolated moderate convection is
seen from 07N to 11.5N between 40W and 43W.

Two tropical waves are located across the western Caribbean, one
along 81W, moving W near 15 knots, and a second along 84W, moving
W at 10 to 15 knots. Scattered to locally numerous moderate to
strong convection is observed from 15N to 18.5N and between 81W
and 87W. The associated moisture and wind field of these two waves
are expected to merge during the next 24 hours as this feature
moves across Central America, the Gulf of Honduras and into the
Yucatan Peninsula Wed night.

...MONSOON TROUGH/ITCZ...

The monsoon trough reaches the Atlantic through the coast of
Mauritania near 10.5N16W to 08.5N30W to 11N40W to 07N49W.
Scattered moderate to isolated strong convection is present from
04N to 15N and E of 25W. Scattered moderate to strong convection
is noted from 06N to 13.5N E of 22W to the coast of Africa.
Scattered moderate isolated strong convection is noted from 03.5N
to 10N between 30W and 40W.

GULF OF MEXICO...

A weak high pressure regime continues to dominate the Gulf of
Mexico, promoting fairly tranquil weather conditions across the
basin. Moderate ENE-NE winds are found offshore NW and W Yucatan
peninsula, while light to occasionally moderate anticyclonic winds
are noted elsewhere. Seas of 3-4 ft are occurring across the
eastern Bay of Campeche and W Gulf waters, while 1-3 ft prevail
in the remainder of the Gulf.

For the forecast, the weak high pressure centered across the SE
Louisiana coastal waters will drift ESE in the north-central Gulf
through tonight. A stalled front across the NE Gulf coast states
will sink S and settle just north of the northern Gulf today and
linger in this area through Thu. This will increase winds across
the northeast and north- central Gulf with moderate westerly
winds. A tropical wave currently located over Honduras and
Nicaragua will move W across Central America through Thu and
emerge over the Bay of Campeche Thu night, where an area of low
pressure could form on Friday. Active weather and fresh easterly
winds are expected to accompany this wave as it exits the Yucatan
Penninsula into the Gulf. Some gradual development of this system
is possible while it moves northwestward over the southwestern
Gulf of Mexico through the weekend.

CARIBBEAN SEA...

Aside from the convection discussed in the Tropical Waves section,
isolated showers and thunderstorms dot the waters north of 19N
between the Windward Passage and Yucatan Channel. The rest of the
basin enjoys tranquil weather conditions. A weak pressure
gradient supports moderate or weaker easterly trade winds across
the basin, except for locally fresh to strong trades off N
Colombia and the Gulf of Venezuela, with fresh to local strong
winds in the Gulf of Honduras. Seas are in the 3-5 ft range in
the south- central Caribbean as well as in the Gulf of Honduras.
Seas of 1-3 ft prevail elsewhere.

For the forecast, the two tropical waves in the western Caribbean
are expected to continue generating strong thunderstorms across
NE portions of Honduras and Nicaragua and across the Gulf of
Honduras. This active weather is expected to shift gradually
westward with the tropical waves through Wed night. Weak 1015 mb
high pressure is centered near 25N70W and yielding generally
moderate trade winds across much of the basin. This high will
strengthen modestly behind the exiting tropical waves tonight
through Fri night to gradually bring a return of fresh to strong
trade winds across the south-central basin. A tropical wave
accompanied by a very broad surface trough will move across the
Tropical Atlantic waters Thu night, across the eastern Caribbean
Fri, and the central Caribbean Fri night and Sat.

ATLANTIC OCEAN...

Short lines of thunderstorms continue to develop across the NW
waters early this morning, ahead of a frontal boundary off the SE
United States coast. Gentle moderate SW winds are combining with
divergent winds aloft sustain these lines of convection to the N
of 28N between 67W and 79W. Farther south, a weak surface trough
persists from Puerto Rico to 27N65W, and is interrupting the
Atlantic ridge from extending further SW into the region, leaving
a weak 1015 mb high centered near 25N70W. Scattered showers and
thunderstorms are seen across the waters north of the Caribbean
islands to 21N between 60W and 70W. The remainder of the tropical
Atlantic is dominated by an expansive subtropical ridge positioned
north of the Azores, maintaining tranquil weather conditions.
Light to moderate anticyclonic winds and seas of 3-5 ft are found
W of 55W. Gentle to locally fresh easterly trade winds and seas of
4-7 ft are noted between 22W and 55W. Fresh to strong NE winds
and seas of 7-11 ft are present N of 18N and E of 22W, with the
strongest winds and highest seas occurring off NW Mauritania and
SE Western Sahara. Elsewhere, moderate or weaker winds and seas of
3-5 ft prevail.

For the forecast W of 55W, the weak high pressure near 25N70W will
collapse through tonight as the weak trough N of Puerto Rico
drifts W. A stalled frontal boundary just NW of the area will
drift SE to near the NE Florida waters today and linger across the
region through Thu, which will maintain active weather N of 28N
between Florida and 68W. High pressure will reestablish across the
SW N Atlantic waters Wed night through Fri and lift northward
Sat.

$$
Stripling
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