641
AXPZ20 KNHC 162341 CCA
TWDEP

Tropical Weather Discussion...Corrected
NWS National Hurricane Center Miami FL
2205 UTC Mon Sep 16 2024

Corrected ITCZ/Monsoon Trough section

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 1800 UTC surface analysis and satellite imagery through
2145 UTC.

...TROPICAL WAVES...

The southern portion of a tropical wave extends 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...Corrected

The monsoon trough extends from along the coast of northwest
Colombia, westward to across northern Costa Rica, and to 10N85W
to 08N92W to 10N98W to 11N105W to 10N114W. The ITCZ extends from
12N116W to 09N130W to beyond 09N140W. Scattered moderate to
isolated strong convection is seen from 05N to 10N between 77W
and 85W. Numerous moderate convection is within 180 nm south of
the iTCZ between 126W and 131W, and also within 60 nm north of
the trough between 88W and 92W and within 60 nm south of the
ITCZ between 131W and 135W.

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

The remnant low of former tropical cyclone Ileana is over the
central Gulf of California near 28N111W with a pressure of 1008
mb. It is moving slowly in a general northward motion. Latest
visible satellite imagery shows that is it just about to move
inland the NW part of Mexico. Isolated small showers are within
60 nm inland the coast of Sonora 27N to 29N. Mostly moderate
southerly winds are east of the low, and light to gentle NW to N
winds are elsewhere over the central section of the Gulf from 17N
to 28N W of 111W. Seas are 3 to 4 ft over the central section of
the Gulf, 4 to 5 ft over the northern section and 2 to 3 ft over
the southern section.

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. 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 variable 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. Widely scattered
thunderstorms have shifted off the coast and into the nearshore
waters of Michoacan and Colima as this activity is being driven
by strong east flow around the southern periphery of a large
mid to upper-level anticyclone that is centered near 23N106W

For the forecast, the remnant low former of tropical Cyclone
Ileana will continue to weaken as it drifts in a general
northward direction inland NW Mexico, dissipating tonight.
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 late
tonight into 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 is
supporting gentle to moderate northerly winds across the Baja
offshore waters. These winds are expected to increase slightly
tonight Mon night 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...

Recently, winds have become moderate to fresh NE in direction
across the Papagayo region. Seas there are 3 to 5 ft. Elsewhere
Light and variable winds prevail across the regional waters north
of 10N. Seas there range 4 to 5 ft in south swell. S of 10N,
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. A very moist and unstable atmospheric
environment is sustaining numerous showers and thunderstorms
along the Central America coast from Costa Rica to Panama, with
similar activity present along the coast of Colombia. All of
this activity extends well offshore to 90W, and inland the
aforementioned geographic locations. Scattered showers and
thunderstorms are just along the coast of Guatemala and well
inland from there.

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 145W,
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 20N and W of 123W, except W of 135W
where locally strong trades are likely due to a stronger gradient
between a weak trough that is along 129W and the broad ridge
mentioned earlier. Seas are 7 to 8 ft in NE swell are west 135W,
and 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 southwest to west 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.

$$
Aguirre