000
AXPZ20 KNHC 211431
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Fri May 21 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
1430 UTC.

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

The monsoon trough extends from 09N78W to 12N104W to 09N124W. 
The ITCZ axis continues from 09N124W to 07N140W. Scattered 
moderate isolated strong convection is noted from 03N to 08N 
between 86W and 92W, and from 08N to 10N between 94W and 125W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A surface ridge extends west of the Baja California peninsula. 
The pressure gradient between the ridge and a surface trough over
the Gulf of California is supporting fresh to strong winds west 
of Baja California Norte and moderate to fresh winds west pf Baja
California Sur. A cold front is moving across the northern Gulf 
of California, with fresh to strong SW winds south of the front. 
Light to gentle winds prevail elsewhere across the forecast 
waters. Seas are in the 9-12 ft range west of Baja California 
Norte and 7-9 ft west of Baja California Sur. Seas are in the 7-8
ft range elsewhere over the open waters off Mexico. 

For the forecast, fresh to locally strong NW winds west of Baja 
California Norte will spread S to the waters offshore Baja 
California Sur into the weekend. In the Gulf of California, some 
fresh wind is expected in northern areas today. Seas will 
increase west of Baja California today in mixed NW and SW swell. 
Fresh northerly winds are expected to pulse in the Gulf of 
Tehuantepec this weekend. Gentle to moderate winds will prevail 
elsewhere into early next week.  

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

Light to gentle winds prevail north of the monsoon trough, with 
gentle to moderate S winds south of the monsoon trough. Seas are 
in the 6 to 8 ft range 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 into Sat, 
then subside. Moderate to 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 into early next week 
elsewhere.

REMAINDER OF THE AREA...

The subtropical ridge continues to dominate the waters north of 
15N. The pressure gradient between this area of high pressure and
lower pressure in the vicinity of the ITCZ and within the monsoon
trough is supporting moderate to fresh winds north of the ITCZ
and monsoon trough and west of 120W. 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 in the 8 to 10 ft range. S to 
SW swell is evident east of 120W and south of 15N, where seas are
averaging 8 to 9 ft. 

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 today 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 tonight. Little
change is expected into early next week.

$$
AL