196 
AXPZ20 KNHC 200900
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 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 0600 UTC surface analysis and satellite imagery through
0900 UTC.

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

The monsoon trough extends westward from 09N84W to 1010 mb low 
pressure near 10N98W to 11N110W. The ITCZ continues from 11N110W
to 10N126W to 07N134W to beyond 07N140W. Scattered moderate 
isolated strong convection is noted from 05N to 11N between 132W
and 140W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Scatterometer data indicates moderate NW winds are west of Baja 
California. Seas are 6 to 8 ft in mixed NW and S to SW swell. 
Light to 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 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...

Scatterometer data shows light to gentle winds in the offshore 
waters of Central America and northwest South America. Seas are 
6 to 7 ft in SW swell, except 7-9 ft in Ecuadorian waters.

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. Light to gentle winds are 
expected to continue through the weekend in the forecast waters.

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 a large area of moderate 
trade winds north of the ITCZ, with 6 to 8 ft seas. Gentle to 
moderate trade winds are noted elsewhere. SW swell is evident 
farther east, with seas in excess of 8 ft reaching as far north 
as 10N east of 125W. A weak low pressure area is centered well 
south of Tehuantepec near 10N98W. 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 north of the ITCZ and west of 125W, with seas 
building to around 8 ft. 8 to 10 ft seas west of Baja California
tonight will spread westward in the northern forecast waters 
through Sat morning. Seas will continue to be 6 to 7 ft east of 
125W in SW swell. Looking ahead, little change is expected into 
early next week.

$$
Mundell