000
AXPZ20 KNHC 202106
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu May 20 2021

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
2030 UTC.

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

The monsoon trough extends westward from 10N86W to a 1009 mb low
pressure near 10.5N98.5W to 10N110W. The ITCZ continues from 
10N110W to 09N133W to beyond 08N140W. Scattered moderate isolated
strong convection is noted from 09N to 10N between 98W and 99W, 
and from 07N to 12N between 124W and 139W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Fresh NW winds are currently west of Baja California Norte, where
seas are 8 to 9 ft. Moderate N winds are offshore Baja 
California Sur. Gentle to moderate SE to S breezes and slight 
seas prevail in the Gulf of California. Farther south, gentle W 
to NW winds and 6 to 8 ft seas in S swell are noted.

For the forecast, fresh NW winds west of Baja California Norte will
spread S to the waters offshore Baja California Sur this evening.
These fresh NW winds will then persist west of Baja California
through Sun. Seas will increase west of Baja California tonight 
and Fri in mixed NW and SW swell. Moderate to fresh north winds 
are expected to pulse in the Gulf of Tehuantepec this weekend. 
Gentle to moderate winds will prevail elsewhere through Mon. 

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

The latest ASCAT data shows light to gentle winds in the 
offshore waters of Central America and Colombia, with moderate S
winds offshore of Ecuador. Seas are 6 to 8 ft in S to SW swell, 
except 8 to 9 ft in the waters off Ecuador and southern 
Colombia.

For the forecast, long period cross-equatorial southerly swell 
will continue to impact the offshore forecast waters through
early Sat, then subside Sat night. Moderate to locally fresh E 
winds are expected to pulse in the Gulf of Papagayo this weekend 
through early next week. Light to gentle winds are expected to 
continue through the weekend elsewhere.

REMAINDER OF THE AREA...

The subtropical ridge continues to dominate the waters north of 
15N. The pressure gradient between it and comparatively lower 
pressure in the deep tropics supports fresh NE trade winds north
of the ITCZ and west of 130W. The latest ASCAT data also shows
fresh NE winds north of 23N between 120W-130W. Seas are 6 to 8 
ft across much of the open Pacific west of 115W, except for north
of 25N and east of 125W, where seas are 8 to 10 ft. S to SW 
swell is evident east of 120W and south of 15N, where seas are
averaging 8 to 9 ft. A weak low pressure area is centered well 
south of southern Mexico near 10.5N98.5W.

For the forecast, reinforcing high pressure will allow the area
of fresh trade winds to the north of the ITCZ to expand in areal
coverage tonight and Fri to cover the area west of 115W. This
will cause the area of 8 to 10 ft seas currently west of Baja 
California to spread westward. Seas will build to 8 to 9 ft over 
much of the area, except 10 to 12 ft north of 22N and east of 
125W. S to SW swell south of 15N and east of 115W will subside
late Fri. Looking ahead, little change is expected into early 
next week.

$$
Hagen