000
AXPZ20 KNHC 120908
TWDEP

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

...TROPICAL WAVES...

The axis of a tropical wave extends along 86W north of 03N 
northward into northern Central America, moving W at around 10 
kt. The wave was previously enhancing convection over parts of 
Honduras, Nicaragua and Costa Rica. Now, a cluster of moderate to
isolated strong convection has developed ahead of the wave axis N
of 12N between 88W and 92W affecting the coastal waters El
Salvador and Guatemala.

The axis of a tropical wave extends along 102W from 04N to 15N 
and is moving W at around 10 to 15 kt. The wave is accompanied 
by a broad area of low pressure. Isolated to scattered moderate 
convection is from 07N to 15N between 100W and 109W. A cluster 
of moderate convection has recently developed near Acapulco, and 
covers the waters N of 15N between 98W and 100W. Fresh to strong
E to SE winds are noted mainly on the E side of the wave axis 
from 10N to 12N between 98W and 102W. Environmental conditions 
are forecast to be conducive for gradual development, and a 
tropical depression could form by midweek well offshore the 
southwestern coast of Mexico while the disturbance moves westward
to west- northwestward at 10 to 15 kt.

The axis of a tropical wave extends along 125W from 04N to 18N, 
moving W at around 10 to 15 kt. Scattered moderate convection is 
where the wave meets the monsoon trough from 09N to 11N between 
120W and 125W.

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

The monsoon trough extends from western Colombia near 07N78W to 
09N90W to 09N100W to 10N110W to 1011 mb low pres located near 
14N119W to 11N125W. The ITCZ extends from 10N128W to 09N140W. 
Aside from the convection related to the tropical waves described
above, scattered moderate convection is from 06N to 12N W of 130W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A ridge dominates the offshore forecast waters of Baja California
producing gentle to moderate NW-N winds and seas of 4-6 ft based
on latest altimeter pass. Light to gentle winds are noted elsewhere
across the offshore waters of Mexico, except in the Tehuantepec 
region where fresh to strong N-NE winds are blowing, with seas 
to 8 ft. 

For the forecast, a surface ridge will continue to extend over 
the waters W of Baja California peninsula over the next several 
days. Gentle to moderate NW-N winds will prevail through midweek.
Light to gentle breezes will persist off southern Mexico through
midweek. In the Gulf of California, mainly gentle to moderate 
southerly winds are expected over the next several days, with 
the exception of moderate to locally fresh SE-S winds, with seas
of 3-5 ft in the northern part of the Gulf. Fresh to strong 
northerly winds are forecast in the Tehuantepec region most of 
the work week, with seas building to 10 or 11 ft beginning on 
Wed.

An area of low pressure is forecast to develop south of the Gulf of 
Tehuantepec around midweek and move westward or west-northwestward 
at 10 to 15 kt, well offshore of the southern coast of Mexico. 
Environmental conditions are expected to be favorable for development
of this system, and a tropical depression is likely to form by 
late this week.

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

Fresh to locally strong NE-E winds and seas to 8 ft are noted in
the Papagayo region. Light winds are north of the monsoon trough
with gentle to moderate winds south of the monsoon trough. Seas 
mostly range 5 to 8 ft, with 8 to 9 ft seas between Ecuador and 
the Galapagos Islands.

For the forecast, fresh to locally strong NE-E winds will continue
to pulse across the Papagayo region through tonight, and then 
again Wed night into Thu. Elsewhere, gentle to moderate southerly
flow will prevail south of 10N through the week, with light to 
gentle breezes north of 10N. Large swell from the Southern
Hemisphere will continue to propagate across the waters between 
Ecuador and the Galapagos Islands through at least Wed. Seas 
will continue to be 8 to 9 ft in this area, reaching as far north
as the offshore waters of western Panama. Altimeter data provided
observations of 9-10 ft seas near the coast of Ecuador. 

REMAINDER OF THE AREA...

A surface ridge dominates the northern forecast waters and extends
from a 1029 mb high pressure located near 40N140W. Recent satellite
derived wind data show gentle to moderate winds on either side 
of the ITCZ/Monsoon trough W of 120W. Seas in that area are 
generally in the 5 to 7 ft range in mixed NE and S swell. Fresh 
NE winds and seas of 8 ft are observed over the NW corner of the 
forecast region, particularly N of a line from 30N134W to 27N138W
to 28N140W. These marine conditions will persist through late 
tonight. Trade winds N of the convergence zone are expected to 
relax through Tue as a surface trough drifts westward across the 
region. Moderate to fresh trade winds will return by midweek as 
the trough moves W of the forecast area.

$$
GR