000
AXPZ20 KNHC 180853
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 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 0600 UTC surface analysis and satellite imagery through
0830 UTC.

...SPECIAL FEATURES...
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 through late Tue, seas should subside below 12 ft by 
late tonight.

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 03N81W, moving west at 5-10 kt. Scattered moderate
convection is active from 08N to 12N between 90W and 95W.

...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.

Low pressure is moving eastward over the Colorado River Valley 
in between higher pressure over the eastern Pacific and northwest
Mexico. This pattern is supporting strong to near-gale force SW
gap winds across the northern Gulf of California. These winds
have diminished slightly from gale-force winds earlier this
evening. Moderate to rough seas are associated with these gap
winds across the northern Gulf. The pattern is also supporting
fresh NW winds off Baja California Norte, as noted in recent
scatterometer satellite data. Concurrent altimeter satellite and
Sofar buoy data confirmed the large swell off Baja California
mentioned in the Special Features section, with 10-13 ft 
combined seas north of Cabo San Lazaro. Gentle breezes are noted 
elsewhere. Seas are 6-9 ft off Baja California off Baja 
California Sur south of Cabo San Lazaro, 4-6 ft elsewhere off 
southern Mexico, and 1-3 ft over the central and southern Gulf of
California.

For the forecast, 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. Scattered showers and thunderstorms are active south of
Panama near the tropical wave.

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 40N138W. 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. Trade wind convergence is supporting scattered
showers and thunderstorms are active from 08N to 10N west of 
125W.

For the forecast, the aforementioned ridge should gradually
weaken while retreating northward today. 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