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Eastern North Pacific Tropical Weather Discussion


346 
AXPZ20 KNHC 210744
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Mon Jul 21 2025

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
0700 UTC.

...TROPICAL WAVES...

A tropical wave has its axis near 105W from 04N northward to 18N
just offshore SW Mexico, moving westward around 20 kt. Nearby
convection has dissipated during the past several hours.

A tropical wave has its axis near 133W from 05N to 20N, moving 
westward at around 10 kt. Scattered moderate convection is noted
from 14N to 6.5N between 129W and 132W.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from near northern Colombia at 11N76W
to across portions of Panama and Costa Rica to 08N100W to 07N120W
to 13N133W. The ITCZ extends from 13N133W to beyond 11N140W.
Scattered moderate isolated strong convection is noted from 05N 
to 10N between 77W and 87W, and from 05N to 11N between 91W and
101W. Scattered moderate convection is noted from 06N to 10N
between 110W and 116W, and from 07.5N to 12.5N between 118W and
125W.

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A surface trough extends from Baja California Sur to across the
central Gulf of California to NW mainland Mexico California. High
pressure ridging is west of Baja California. The resultant
pressure gradient is supporting moderate winds in the northern
Gulf of California and offshore Baja California Sur per recent
ASCAT data. Fresh to locally strong gap winds continue in the 
Gulf of Tehuantepec per the same ASCAT data. Elsewhere, light to
gentle winds prevail. Seas in offshore waters are 3 to 5 ft, 
except 6 to 8 ft in and downwind of the Gulf of Tehunatepec. In 
the Gulf of California, seas are 2 to 4 ft north of 30N, and 1 
to 3 ft elsewhere.

For the forecast, moderate to fresh SE winds will pulse in the 
northern Gulf of California into Tue night. Pulsing fresh to 
locally strong north gap winds will continue in the Gulf of 
Tehuantepec into Wed night as a diurnal surface trough is 
expected to move from the Yucatan Peninsula to Veracruz, Mexico, 
for the next several days. Elsewhere, moderate or weaker winds 
and moderate seas will prevail. Winds may freshen west of Baja 
California by mid-week as the pressure gradient tightens 
slightly, then increasing to fresh to strong mainly north of Cabo
San Lazaro by the end of the week.

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

Fresh to locally strong northeast to east winds are in the Gulf 
of Papagayo region. Seas with these winds are 5 to 7 ft. 
Moderate southerly winds are over the waters between Ecuador and 
the Galapagos Islands. Light and variable winds are elsewhere 
across the Central America offshore waters, except moderate in
the Gulf of Panama. Seas over the remainder of the waters are 3 
to 6 ft in south to southwest swell.

For the forecast, pulsing fresh to locally strong northeast to 
east winds will continue in the Gulf of Papagayo through early 
Thu, then pulsing moderate to fresh thereafter. Moderate to 
locally fresh winds associated with these gap winds will continue
to affect the outer offshore waters of El Salvador and Guatemala
into late week. Otherwise, gentle to moderate southerly winds 
will continue between Ecuador and the Galapagos Islands. 

...REMAINDER OF THE AREA...

High pressure is analyzed centered well northwest of the 
discussion area. A ridge extends from the high center SSE to 
around 23N and 115W. A tropical wave is south of the ridge near 
133W. Winds near this wave are fresh to locally strong, with 
seas of 7 to 9 ft. The pressure gradient between the ridge and 
the tropical wave is also allowing for moderate to fresh 
northeast to east winds to exist from 11N to 21N between 130W 
and 140W. Gentle to moderate northeast to east trades are 
elsewhere north of the monsoon trough and ITCZ, along with 4 to 
7 ft seas. South of the monsoon trough and ITCZ, winds are 
moderate, except locally fresh near 140W, with seas of 6 to 7 ft
in southeast to south swell, except to around 8 ft near 
03.4S120W, and also near the Equator at 140W.

For the forecast, the tropical wave currently along 133W has a
low chance for some slow development through today as it moves 
westward at around 10 kt before conditions become unfavorable 
Mon night. Otherwise, the moderate to fresh northeast to east 
trades north of the monsoon trough and the ITCZ will gradually 
shift to the western part of the area as the gradient between the
tropical wave and the high pressure tightens. Guidance suggests 
that seas may reach around 10 ft with the tighter gradient over 
the western part of the area later today through Tue night with 
fresh to strong winds. Seas will linger around 8 ft south of the
Equator and west of 105W through the early part of this week.

$$
Lewitsky