908
AXPZ20 KNHC 170321
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Sep 17 2024

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0230 UTC.

...TROPICAL WAVES...

The southern portion of a tropical wave is along 86W extending
from Belize to western Honduras and continuing southward over
the eastern Pacific to near 09N. It is moving westward at 5-10
kt. Scattered moderate convection is noted within 120 nm either
side of the wave where it just crosses the monsoon trough.
Otherwise, no significant convection is occurring with this wave.

A tropical wave is along 105W from southwestern Mexico to near
08N, moving westward at about 10 kt. Scattered moderate
convection is within 120 nm east of the wave from 09N to 10N.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from 11.5N73.5W to 10.5N85W to 08N93W
to 10.5N104W to 10.5N122W. The ITCZ extends from 10.5N122W to
08.5N137W to beyond 09N140W. Scattered moderate convection is
seen from 03.5N to 09N E of 96W. Scattered moderate to strong
convection is within 60 nm of the coasts from NW Nicaragua along
87W to Cabo Corrientes along 106W, from 10.5N to 12N between 96W
and 105W, within 90 nm NW of a line from 15.5N112W to 10N122W,
and from 06.5N to 12N between 122W and 136W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

The remnants and associated moisture of former tropical cyclone
Ileana has moved well inland across Sonora, Mexico this afternoon
and evening, bringing scattered showers and an isolated moderate
thunderstorm or two. Gentle to moderate southerly flow prevail
across the central Gulf of California in its wake, with seas 3 ft
or less. A narrow plume of fresh to strong SW gap winds extends
northeastward across the northern Gulf from the coast along Campo
Huerfanito to near La Choya. Seas there are 4 to 6 ft, while
winds and seas are lower on either side. Elsewhere, light and
variable winds prevail across the southern Gulf south of 25N,
where seas are 2 to 3 ft.

A persistent broad and weak ridge extends southeastward into the
area waters tonight. The resultant pressure gradient is
producing gentle to moderate NW winds prevail across the
near and offshore waters of Baja California, and extend to Cabo
Corrientes and the Revillagigedo Islands. Winds have increased t
fresh this evening along the coast near Punta Abreojos. Seas
across these area waters are generally 3 to 5 ft except to 6 ft
across the waters NW of Isla Guadalupe. Generally, light and
mostly westerly winds dominate the waters from Manzanillo to the
Tehuantepec region where seas are 4 to 5 ft in southerly swell
east of 103W, and with mixed NW and S swell west of 103W.
Scattered moderate to strong thunderstorms have shifted off the
coast and into the nearshore waters from Cabo Corrientes to
Chiapas.

For the forecast, fresh to strong SW winds will continue over
portions of the northern Gulf of California through early Tue
morning. A brief instance of fresh to strong N winds is expected
N of 30N early Tue morning as the tail-end of a weak cold front
sweeps eastward across the far northern Gulf of California.
Elsewhere, broad high pressure northwest of the area support
gentle to moderate northerly winds across the Baja offshore
waters will increase slightly tonight through Wed morning. Winds
will pulse to fresh during the afternoons and evenings off the
Baja California coast through Fri. New northerly swell will move
into the regional waters Tue through Wed, raising seas slightly
before slowly subsiding Thu and Fri.

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

Moderate to fresh NE gap winds prevail across the Papagayo
region this evening, where seas are 4 to 5 ft. Elsewhere Light
and variable winds prevail across the regional waters north of
09N. Seas there range 4 to 5 ft in south swell. S of 09N, gentle
to moderate southwest to west winds prevail. Seas are 4 to 6 ft
in south to southwest swell there, except 2 to 3 ft inside the
Gulf of Panama. Very active thunderstorms along the Central
America coast from Costa Rica to Panama and Colombia this
afternoon has diminished considerably this evening.

For the forecast, gentle to moderate southwest to west winds
will continue south of the monsoon trough through Tue, then
freshen modestly Wed and Fri. North of the trough, light to
gentle winds are expected through Thu. The moderate to fresh
gap winds across the Papagayo region will become gentle to
moderate east winds on Tue before shifting SE. Moderate seas in
primarily southwest swell will continue through Wed before
increasing Wed night through Fri, with little change expected
afterward.

...REMAINDER OF THE AREA...

A 1030 mb high continues across the NE Pacific along 153W,
extending a broad ridge southward into the region, dominating the
area north of the ITCZ and west of about 122W. The related
pressure gradient is producing generally moderate to fresh
northeast trades S of about 21N and W of 124W, except W of 135W
where locally strong trades are occurring due to a weak low level
trough shifting westward across that area. Seas are 7 to 8 ft in
NE swell are west 135W, while seas over the rest of the area are
5 to 7 ft in mixed swell. Gentle to moderate winds and seas 4 to
5 ft are noted N of 27N. Moderate to fresh S to SE winds
continue south of the ITCZ W of 130W, with gentle to moderate
winds elsewhere south of the monsoon trough. Seas are 5 to 7 ft
south of the monsoon trough, and 4 to 7 ft east of 120W.

For the forecast, the aforementioned high pressure will drift SW
through the rest of the week, with the associated ridge changing
little. This will result in moderate to fresh trades south of
20N and west of 130W, and seas 6 to 8 ft in NE swell through Wed
morning. Winds will become moderate to locally fresh Wed through
Fri. Moderate to fresh SW to W winds and mostly seas of 4 to 7
ft are expected elsewhere south of the monsoon trough through
Wed night before a modest increase E of 110W Thu and Fri.

$$
Stripling