000
AXPZ20 KNHC 220301
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue Aug 22 2023

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
0300 UTC.

...TROPICAL WAVES...

A tropical wave axis is near 95W north of 04N, moving westward 
at 10 to 15 kt. Scattered moderate convection is from 11N to 13N
between 96W and 98W.

A tropical wave extends from 03N to 16N with axis near 109W, 
drifting westward 5 to 10 kt. No significant convection is
evident with this tropical wave.

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

The monsoon trough axis extends from 09N83W to 08N100W to  
14N110W to 09N130W. The ITCZ extends from 09N130W to beyond
07N140W. Scattered moderate convection is evident from 05N to 07N
between 85W and 09W. 

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

Fresh to locally strong northerly gap winds continue across the 
Gulf of Tehuantepec with seas to 8 ft this evening. A ship
observation off Cabo San Lazaro confirmed moderate to fresh NW 
winds in that area, indicative of a larger area of moderate to 
fresh NW winds off Baja California Sur and the southern Gulf of
California, between the subtropical ridge to the west and lower
pressure over north-central Mexico. Gentle to moderate winds
persist elsewhere, with 4 to 6 ft seas in open waters. A few
showers and thunderstorms are noted inland over the coastal terrain
of southern Sinaloa, but so far not impacting the marine area.

For the forecast, the northerly gap winds will continue to pulse
mainly at night across the Gulf of Tehuantepec through Thu 
night. Looking ahead, a broad area of low pressure is expected to
form offshore of the coast of Central America or southern Mexico
during the next few days. Any subsequent development of this 
system should be slow to occur while it drifts toward the 
northwest or north-northwest, possibly supporting fresh winds and
rough seas off western Oaxaca and Guerrero Thu night through Fri
night. 

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

Buoy data from along the monsoon trough near 95W show fresh
westerly winds, part of a larger area of fresh to locally strong
SW flow south of the monsoon trough to about 05N, and west of 
100W, reaching as far east as the offshore waters of Costa Rica 
and western Panama. Recent altimeter data showed seas reaching 
near 8 ft in this area. The convergent SW flow is supporting a 
large area of showers in the same area. The lowering pressure
over the monsoon trough is also supporting fresh gap winds across
the Gulf of Papagayo, which in turn supporting a small area of
showers and thunderstorms just off the coast. Gentle breezes and
moderate seas are noted elsewhere. 

For the forecast, moderate to locally fresh E winds will pulse 
at night across the Gulf of Papagayo region through Wed. Fresh to
strong SW monsoon winds will persist over offshore waters of 
Costa Rica and western Panama with 6 to 8 ft seas into mid-week 
as broad low pressure develops along the monsoon trough. The low 
and associated winds and seas will lift northward into Nicaragua 
offshore waters Wed and Thu then diminish. 

...REMAINDER OF THE AREA...

Fresh southerly winds remain south of the monsoon trough between
90W and 100W with combined seas of 6 to 8 ft. Also, 7 to 8 ft 
seas are north of 28N between 130W and 140W in mixed swell. 
Elsewhere in the basin, a weak pressure pattern prevails 
sustaining moderate or weaker and moderate seas.

For the forecast, SW winds will continue to increase south of 
the monsoon trough and east of 120W through midweek. High 
pressure will weaken modestly west of 120W through mid-week and 
bring a return to moderate NE trade winds south of 20N.

$$
Christensen