555 
AXPZ20 KNHC 180344
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Jul 18 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 0000 UTC surface analysis and satellite imagery through
0330 UTC.

...TROPICAL WAVES...

A tropical wave has its axis north of 85W to inland Central
America. It is moving westward at about 15 kt. Isolated showers 
are near the southern part of the wave.

A tropical wave has its axis near 116W from 06N to 18N, moving
westward at 5 to 10 kt. Numerous moderate isolated strong 
convection is within 240 nm west of the wave from 06N to 10N.
Scattered moderate to isolated strong convection is within 180 
nm east of the wave from 10N to 14N. 

A tropical wave has its axis near 126W from 06N to 17N, moving 
westward around 10 kt. Numerous moderate convection is east of 
the wave to 120W from 10N to 15N.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from northwest Colombia to 09N79W
to 07N91W to 09N103W to 10N115W and to 10N125W, where it 
transitions to the ITCZ and continues to 10N125W to 10N130W and 
to beyond 10N140W. Aside from convection associated with the
tropical waves, scattered moderate convection is seen 
within 180 nm south of the trough between 104W and 110W and 
within 180 nm north of the trough between 108W and 115W.  

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

Moderate to fresh northwest to north winds are ongoing in the 
Gulf of Tehuantepec region along with seas of 5 to 7 ft. Elsewhere,
locally moderate or weaker winds continue along with seas of 4 to
6 ft in long-period south to southwest swell. In the Gulf of 
California variable winds of 5 kt or less are present, except
in the northern portion where light to gentle south to southwest
winds are occurring. Seas in the Gulf are 3 ft or less, except 
in the southern where higher seas of 3 to 5 ft in southeast swell
are found.

satellite imagery shows large clusters of scattered moderate to
strong convection moving westward along and just offshore the
coast of Mexico from just north of Las Tres Marias Islands and 
also over the state of Nayarit reaching northward to the vicinity 
of Los Mochis.

For the forecast, moderate southeast winds will pulse over the 
northern Gulf of California, reaching moderate to fresh speeds 
Sun morning as a low pressure develops just north of the area. 
Moderate to locally fresh southeast winds will then prevail 
through Tue night as the low remains stationary. Pulsing fresh to
strong N gap winds will continue in the Gulf of Tehuantepec 
through Sun night as a surface trough is expected to move from 
the Yucatan Peninsula to Veracruz the next several days. 
Afterward, high pressure over the Gulf of America will shift 
eastward, and winds in Tehuantepec will diminish to moderate to 
fresh speeds through Tue night. Rough seas are forecast to 
develop in Tehuantepec Fri night through late Sat. Elsewhere, 
moderate or weaker winds and moderate seas will prevail. 

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

Northeast to east winds have increased to fresh to strong speeds
in the Gulf of Papagayo. Seas with these winds are 5 to 8 ft.
The wind fetch extends as far as 100W, including the outer 
offshore waters of El Salvador and Guatemala. Moderate southerly 
winds are over the waters between Ecuador and The Galapagos 
Islands along with seas of 6 to 8 ft in south to southwest 
swell. Light and variable winds are elsewhere over the offshore
waters of El Salvador while light to gentle southwest to west
winds are the offshore waters of Costa Rica and northern Panama 
and light to gentle west to northwest winds are over the offshore
waters of the remainder of Panama and Colombia. Seas over these 
waters are 5 to 7 ft in south to southwest swell.

For the forecast, pulsing fresh to strong northeast to east 
winds will continue in the Gulf of Papagayo through Tue night 
with periods of rough seas. Moderate southerly winds are over 
the waters between  associated with this gap wind event will 
continue to affect the outer offshore waters of El Salvador and 
Guatemala through early next week. Otherwise, gentle to moderate 
southerly winds will continue between Ecuador and The Galapagos 
Islands through Tue night along with moderate seas. 

...REMAINDER OF THE AREA...

Strong high pressure of 1033 mb is analyzed well northwest of 
the discussion area at 43N147W. A ridge extends from the high 
center southeastward to 26N130W and to near 23N115W. A couple of 
tropical waves are south-southeast of the ridge between 115W and 
126W. The pressure gradient between the ridge and the wave is 
allowing for moderate to fresh northeast to east trades to exist 
from north of the monsoon trough to 16N between 114W and 125W and 
from the ITCZ to near 17N between 125W and 135W as noted in a 
recent scatterometer satellite data pass. The same scatterometer
satellite data pass indicates gentle to moderate trades 
elsewhere. Seas over these waters are 5 to 7 ft, except for a 
small area of 6 to 8 ft seas in mixed northeast and southeast 
swell from 10N to 16N between 10N and 13N between 130W and 140W. 
Other recent scatterometer satellite data passes generally 
reveal gentle to moderate northeast to east trades elsewhere 
north of the monsoon trough and ITCZ. Recent altimeter satellite
data passes along with a few Sofar Spotter buoy observations 
indicate seas of 5 to 7 ft elsewhere north of the ITCZ and 
monsoon trough. The scatterometer satellite data passes show 
moderate to fresh south to southeast winds south of the ITCZ and 
mostly moderate south to southwest winds south of the monsoon 
trough. Recent altimeter satellite data passes reveal seas of 5 
to 7 ft with these winds, except for higher seas of 6 to 8 ft due
to long- period cross equatorial swell south of about 02N 
between 93W and 118W.

For the forecast, the moderate to fresh northeast to east trades 
will change little north of the monsoon trough and the ITCZ 
through early Sat, then shift to the western part of the area
as the gradient between a tropical wave and the high pressure 
tightens. Guidance suggests that seas may reach around 9 ft 
with the tighter gradient over the western part of the area
Sun into early next week. The cross-equatorail swell is expected
to subside some early on Fri, but perhaps propagate through a 
section of the far south-central waters on Sat.

$$
Aguirre