000
AXPZ20 KNHC 201537
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

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

The monsoon trough extends westward from 11N86W to a 1010 mb low
pressure near 11N98W to 10N109W. The ITCZ continues from 10N109W
to 10N126W to beyond 08N140W. Scattered moderate isolated strong
convection is noted from 05N to 12N between 124W and 140W. 
Scattered moderate convection is within 90 nm SE of the 1010 mb 
low pressure.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Fresh NW winds are currently west of Baja California Norte, where
seas are 7 to 9 ft in mixed NW and S to SW swell. Moderate N
winds are offshore Baja California Sur. Gentle breezes and 
slight seas prevail in the Gulf of California. Farther south, 
gentle W to NW winds and 6 to 7 ft seas in S to SW swell are 
noted.

For the forecast, fresh NW winds will persist west of Baja 
California Norte through Sun. Seas will increase west of Baja 
California tonight and Fri in NW swell. Moderate to fresh north
winds are expected 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...

Light to gentle winds prevail in the offshore waters of Central 
America and northwest South America. Seas are 6 to 8 ft in SW 
swell, except 7 to 9 ft in waters off Ecuador and southern 
Colombia.

For the forecast, long period cross-equatorial southerly swell 
will continue to impact the offshore forecast waters through Fri
night, then begin to subside on Sat. 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 moderate to fresh trade 
winds north of the ITCZ, with 6 to 8 ft seas. SW swell is 
evident farther east, with seas in excess of 8 ft reaching as far
north as 13N east of 125W. A weak low pressure area is centered 
well south of Tehuantepec near 11N98W. Scatterometer data 
indicates moderate to fresh SW winds are south of a diffuse low 
center.

For the forecast, reinforcing high pressure will allow trade
winds to increase to fresh north of the ITCZ and west of 120W, 
with seas building to around 8 to 9 ft. 8 to 10 ft seas west of 
Baja California will spread westward in the northern forecast 
waters through Sat morning. Seas will be 6 to 7 ft east of 125W 
in SW swell Sun and Mon. Looking ahead, little change is 
expected into early next week.

$$
Hagen