797 
AXPZ20 KNHC 200339
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Oct 20 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
0330 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The tight pressure gradient
between high pressure over eastern Mexico and Tropical Depression
Nadine is supporting gale force winds up to 40 kt in the Gulf of
Tehuantepec. Rough seas in N to NE swell are associated with
these winds, with peak seas of 14 to 15 ft. Seas generated from 
this gap wind event will spread well away from the Tehuantepec 
area, with seas 8 ft or greater reaching as far south as 08N Sun
morning. Marine interests transiting across the Gulf of 
Tehuantepec this weekend should be aware of this gap wind event, 
and take the necessary action to avoid hazardous marine 
conditions over the affected waters.

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

The monsoon trough extends from 10N85W to 09N100W to a 1011 mb 
low pressure centered near 15N116W to 12N140W. Scattered moderate
to isolated strong convection is occurring from 06N to 09N
between 80W and 85W, and from 07N to 12N between 104W and 118W.

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

A Gale Warning remains in effect for the Gulf of Tehunatepec. 
Please see the Special Features section for more details.

A 1026 mb high pressure located N of the area near 34N136W 
extends a ridge across the waters west of Baja California, while 
a stationary frontal boundary is analyzed over the central Gulf 
of California. This pattern supports locally fresh NW winds 
offshore of Jalisco through Michoacan, and moderate to locally 
fresh NW winds behind the stationary boundary in the northern and
central Gulf of California. Otherwise, light to gentle winds are
occurring across the remainder of the Mexican offshore waters. 
Seas of 5 to 7 ft prevail off the coast of Baja California, with 
seas of 3 to 5 ft from Cabo Corrientes, southward, and 2 to 3 ft 
in the Gulf of California.

For the forecast, gale force winds and rough to locally very 
rough seas will continue in the Gulf of Tehuantepec through Sun 
morning. Strong N to NE winds and periods of rough seas will then
occur Sun afternoon through the end of next week. Ridging will 
prevail over the offshore waters while a trough meanders between 
the Gulf of California and Baja California, and strong high 
pressure becomes established over central Mexico. This pattern 
will support moderate NW winds over central and southern portions
of the Gulf of California and areas south of Cabo San Lazaro Sun
through next week, with locally fresh to strong NW winds 
occurring Sun night into Tue morning. Looking ahead, after Nadine
dissipates over southern Mexico, its remnants are expected to 
move into the eastern Pacific. The combination of the remnants of
Nadine and influences from the Gulf of Tehuantepec gap wind 
event are forecast to result in the formation of a new low 
pressure system off the coast of southwestern Mexico in a day or 
so. Additional development is expected after that time, and a 
tropical depression is likely to form during the early to middle 
part of next week while the system moves westward at about 15 mph
away from the coast of Mexico. There is a low chance of tropical
formation within the next 48 hours, and a high chance of 
formation over the next 7 days.

Please, read the latest NHC Tropical Weather Outlook at 
www.hurricanes.gov for more details.

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

Moderate S to SW winds and seas of 4 to 7 are occurring south of
the monsoon trough and light to gentle winds and seas of 3 to 5 
ft are noted to the north. Locally rough seas, generated by the 
gap winds in the Gulf of Tehuantepec, are ongoing offshore of 
Guatemala. Scattered moderate to strong convection along the 
periphery of Tropical Depression Nadine is occurring offshore of 
Guatemala and El Salvador. Gusty winds and rough seas are likely 
near convection.

For the forecast, gentle to moderate S to SW winds will occur 
south of the monsoon trough while light to gentle winds will 
prevail to the north. Rough seas generated in the Tehuantepec 
region will propagate across the outer offshore waters of 
Guatemala and El Salvador through Sun, with seas slowly subsiding
on Mon. Elsewhere, mainly moderate to locally rough seas in 
cross equatorial SW swell are expected, with the highest seas, in
the 5 to 8 ft range, between Ecuador and the Galapagos Islands.

...REMAINDER OF THE AREA...

High pressure dominates the forecast waters north of the monsoon
trough, with gentle to moderate NE winds noted in this region.
Seas range from 5 to 7 ft, with local 8 ft waves occurring south
of 15N and west of 131W. A long-period cross equatorial swell is
leading to seas of 8 to 10 ft south of 02N and east of 125W.
Elsewhere, gentle to moderate winds and moderate seas prevail. 

For the forecast, the cross equatorial S swell will lead to rough
seas south of 08N through Mon before seas slowly subside by 
midweek. The high pressure centered to the north of the forecast 
waters will weaken as a cold front approaches from the west by 
the middle of next week. A low pressure may form along the 
frontal boundary on Tue, with a cold front reaching the NW corner
of the forecast region by Tue night. Building NW swell behind 
the front will lead to rough seas north of 25N and west of 130W 
late next week.
 
$$
ADAMS