000
AXPZ20 KNHC 180339
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Mon May 18 2026

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.

...SPECIAL FEATURES...

Northern Gulf of California Gale Warning: A trough moving across the lower Colorado River
Valley associated with deep 988 mb low pressure near Las Vegas is supporting
strong to gale force gap winds into the northern Gulf of California
tonight. Winds will diminish through Mon as 1033 mb high pressure
off southern California builds over the region in the wake of the
trough.

Significant Swell Event West of Baja California Norte: 
Very large, long-period NW swell is causing very rough seas of 12
to 16 ft, north of 27N and east of 125W, including waters near 
Guadalupe Island. This swell will continue to propagate southward
through this evening, causing very rough seas to reach near 26N 
late tonight. As the NW swell gradually decays and retreats 
northward Mon through Mon night, seas should subside below 12 ft 
by late Mon night.

For both events above, please refer to the latest High Seas and 
Offshore Waters Forecasts issued by the National Hurricane Center
at websites: 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and
https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more 
details.

...TROPICAL WAVES...

A tropical wave extends from the southwest Caribbean across
Panama to 03N80W, moving west at 5-10 kt. A few showers and
thunderstorms are active over Panama, mostly related to sea
breeze influences. 

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

A monsoon trough extends from 10N85W to 06N95W. The monsoon
trough extends from 06N95W to 05N140W. Scattered moderate
convection is active from 08N to 12N between 90W and 95W, and
from 07N to 10N between 128W to 140W.

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

Please read the Special Features section above regarding a Gale
Warning and Significant NW swell.

In addition the gale force winds mentioned in the Special
Features section, the pattern is supporting fresh NW winds off
Baja California Norte, coincident with the large NW swell. Gentle
to moderate breezes are noted elsewhere. Combined seas are 5-7 ft
off Baja California Sur, with 4-6 ft off southern Mexico and 1-3
ft over the central and southern Gulf of California. 

For the forecast, the high pressure will build over the area in
the wake of the trough moving through the lower Colorado River
valley. Aside from the winds and seas described in the Special 
Features section, gentle to moderate breezes and mostly moderate 
seas will prevail elsewhere.
 
....OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

A recent scatterometer satellite pass indicated fresh gap winds
downwind of the Gulf of Papagayo, and north of a broad
circulation along the monsoon trough centered near 09N88W. Gentle
breezes and 3-5 ft seas are noted elsewhere primarily with SW
swell. A few thunderstorms are active southwest of Cocos Island.

For the forecast, fresh to strong winds will pulse across the 
Gulf of Papagayo mainly in overnight and early morning hours 
through Thu morning. Elsewhere, gentle to moderate winds along 
with moderate seas in southerly swell are expected through 
midweek.

...REMAINDER OF THE AREA...

A broad ridge covers the waters north of 20N, anchored by 1033 mb
high pressure centered near 39N138W. Fresh to strong NW to N winds
and large NW swell cover the waters north of 20N and east of 
130W. Fresh to strong NE to E winds and 8-9 ft seas are noted
north of 10N west of 125W. Gentle to moderate breezes are noted
elsewhere. Seas are 6-8 ft in S swell south of 10N and west of
120W, with 5-7 ft seas in a mix of NW and SW swell elsewhere over
the tropical Pacific.

For the forecast, the aforementioned ridge should gradually
weaken while retreating northward starting Mon afternoon. This
will allow winds and seas north of the ITCZ to steadily subside
from east to west through midweek, becoming gentle to moderate
winds with 6-8 ft seas by Thu. Winds south of the ITCZ will also
becoming gentle by Thu with higher seas at 5-7 ft in mixed 
swells.

$$
Christensen