000
AXPZ20 KNHC 120245
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Sep 12 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 0000 UTC surface analysis and satellite imagery through
0240 UTC.

...SPECIAL FEATURES...

A broad area of low pressure offshore of southern Mexico is 
producing a large area of disorganized showers and thunderstorms.  
Some gradual development of this system is possible during the next 
couple of days as long as it remains over water, and a tropical 
depression could form tomorrow or early Monday while the system 
moves northwestward or north-northwestward toward the southern and 
southwestern coasts of Mexico.  Thereafter, further development is 
not expected due to interaction with land. Regardless of 
development, this system will likely produce heavy rains across 
portions of southern Mexico during the next couple of days. There
is a medium chance for tropical cyclogenesis within the next 48 
hours. Please see the latest eastern north Pacific Tropical 
Weather Outlook for more information.

...TROPICAL WAVES...

The axis of a tropical wave is near 82W north of 02N, moving 
west at 10-15 kt. Scattered moderate to isolated strong 
convection is noted from 04N to 08N between 80W and 85W.

The axis of a tropical wave is near 96W/97W, moving west at 
10 kt. Scattered moderate to isolated strong convection is noted
from 08N to 14N between 93W and 100W. Low pressure developing 
along the tropical wave will be monitored for the potential for 
tropical cyclogenesis. Please see Special Features section above 
for more information.

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

The monsoon trough extends from 11N86W to 14N95W to 08N132W.
Aside from convection noted in the tropical waves section above,
scattered moderate isolated strong convection is noted from 04N 
to 11N between 85W and 93W. Scattered moderate convection is 
noted from 06N to 13N between 100W and 110W and from 04N to 07N 
between 127W and 132W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section above for details on
the developing area of low pressure with the potential for 
developing into a tropical cyclone.

The remnant low of Olaf is centered near 24N116W. Moderate to
locally fresh winds are over the western semicircle of the
remnant low. Seas continue in the 7-8 ft range. Farther east,
fresh to strong gap winds are funneling through the Gulf of
Tehuantepec in response to developing low pressure, which is
discussed in the special features section above. Elsewhere,
gentle to moderate winds prevail. Seas are in the 7-9 ft range
over the waters off southern Mexico in SW swell. Elsewhere, over
the open waters, seas are in the 5-6 ft range. Over the Gulf of
California, seas are in the 1-3 ft range. 

For the forecast, winds near the remnant low of Olaf will 
diminish to less than 20 kt tonight, but seas to 8 ft will 
persist off Baja California into early next week as different 
groups of NW and S swell move into the region. Farther to the 
southeast, a broad area of low pressure is centered south of 
southern Mexico. Some gradual development of this system is 
possible during the next couple of days as long as it remains 
over water, and a tropical depression could form tomorrow or 
early Monday while the system moves northwestward or north-
northwestward toward the southern and southwestern coasts of 
Mexico. Regardless of development, large southwest swell will 
build seas off southern Mexico through early next week. Coastal 
areas in southern Mexico from Chiapas to Guerrero may see hazard 
surf and heavy rainfall Sat through early next week.

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

Fresh SW winds prevail over the offshore waters of Guatemala and
El Salvador. Seas are in the 6 to 9 ft range off Guatemala and 
El Salvador in SW swell. Farther south, gentle to moderate 
southerly winds persist off Colombia and Ecuador, with seas of 6 
to 8 ft in SW swell.

For the forecast, large SW swell will impact region into early 
next week, along with moderate winds.

REMAINDER OF THE AREA...

A large area of moderate to fresh S to SW winds prevail south of
10N and east of 115W. Seas to 8 ft prevail over much of the 
tropical waters east of 120W, partly due the local wind flow, but
also due in part to a larger area of cross- equatorial SW swell.
Mainly gentle to moderate winds persist west of 120W, with seas 
to 8 ft in southerly swell reaching as far west as 130W south of 
08N and 5 to 7 ft seas elsewhere. Southwest swell will continue 
to propagate through the waters east of 130W through the upcoming
weekend, with seas ranging between 8-11 ft through early next 
week.

$$
AL