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Eastern North Pacific Tropical Weather Discussion


000
AXPZ20 KNHC 130807
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Mon Jul 13 2026

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.

...SPECIAL FEATURES...

Offshore of Southwestern Mexico: A tropical wave is producing a
large area of disorganized thunderstorms and gusty winds a 
couple of hundred nautical miles south of the coast of southern 
Mexico as described with the monsoon trough below. Currently, 
winds are 20 to 25 kt with this system, along with seas of to 8 
ft. Environmental conditions appear favorable for continued 
gradual development, and a tropical depression is expected to 
form in the next 2 or 3 days while the system moves generally 
west- northwestward, well off the coast of Mexico. The latest 
Tropical Weather Outlook gives this system a medium chance of 
tropical cyclone formation in the next 48 hours, and a high 
chance through 7 days. Please read the latest Tropical Weather 
Outlook issued by the National Hurricane Center at 
www.hurricanes.gov for further details. 

...TROPICAL WAVES...

The axis of a tropical wave is near 79W, and extends from near
the NW border of Colombia and Ecuador at 02N northward to near
the Panama Canal and into the Caribbean Sea, moving westward at
around 15 to 20 kt. Any nearby convection is described below in 
the ITCZ/monsoon trough section.

The axis of a tropical wave is near 99.5W, from 04N northward 
over portions of southern and SW Mexico, moving westward at
around 10 to 15 kt. Any nearby convection is described below in 
the ITCZ/monsoon trough section, with additional details also in
the Special Features section regarding the potential for tropical
cyclone formation.

The axis of a tropical wave is along 133W from 04N to 19N, 
moving westward at around 10 kt. A 1008 mb low pressure is 
analyzed along the wave axis near 15N132W. Any nearby convection
is described below in the ITCZ/monsoon trough section.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from 11N74W to 10N86W to 09N94W. The
ITCZ extends from 09N94W to 09N98.5W, then resumes west of a 
tropical wave from 09N101W to 04N119W to 12N131W. Another 
monsoon trough segment extends from 12.5N133.5W to 08N140W. 
Scattered moderate isolated strong convection is noted from 05N
to 09N between 77W and 83W, within 300 nm either side of the ITCZ
between 95W and 114W, and from 12N to 17N between 128W and 132W.
Similar convection is found within 120 nm of the coast between
87W and 95W. Scattered moderate convection is noted from 06N to
12N between 133W and 140W.

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

A ridge dominates the offshore forecast waters of Baja California
supporting gentle to moderate winds per recent ASCAT
scatterometer data, with moderate seas observed by a pair of
recent altimeter passes, in mixed swell. Light to gentle winds
are in the Gulf of California where slight seas prevail. 
Moderate to increasing northerly winds are blowing in the Gulf 
of Tehuantepec with moderate seas. An area of fresh to strong 
winds extends from the coast of Oaxaca to about 11N between 96W 
and 101W along with mainly rough seas. Over the remainder of the
Mexican offshore waters, winds are gentle to moderate from the 
NW and seas are generally moderate, primarily in SW swell. Active
convection is present offshore of the majority of southern and SW
Mexico as described above.

For the forecast, a tropical wave is producing a large area of 
disorganized thunderstorms and gusty winds a couple of hundred 
nautical miles south of the coast of southern Mexico. Please, see
the Special Features section for more details. A ridge will 
continue to dominate the offshore forecast waters of Baja 
California through early Thu, allowing for gentle to moderate NW 
to N winds to continue along with moderate seas in mixed swell. 
In the Gulf of California, mainly gentle winds will prevail 
through Tue night, increasing to moderate to locally fresh in the
central and northern portions midweek. Fresh to strong northerly
winds will pulse in the Gulf of Tehuantepec during the week, 
strongest during the late night and early morning hours, with 
locally rough seas at times. 

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

Fresh easterly winds in the Papagayo region observed by an 
earlier ASCAT pass have likely increased to fresh to strong in 
the past few hours, with moderate to fresh easterly winds 
elsewhere from 10N to 12N. Winds are light to gentle across the 
remainder of the waters per ASCAT and OSCAT scatterometer passes.
Moderate seas dominate the waters. Areas of convection 
associated with the monsoon trough are described above with 
locally higher winds and seas.

For the forecast, fresh to strong gap winds will prevail in the 
Papagayo region mainly at night through at least Fri night along
with moderate to locally rough seas. Fresh to locally strong 
winds and rough seas are forecast to impact the offshore waters 
of El Salvador and Guatemala today due to the departing presence
of a tropical wave several hundred nautical miles south of the 
coast of southern Mexico. Moderate or weaker winds and moderate 
seas in SW swell will prevail elsewhere, except in the lee of the
Galapagos Islands where slight seas are expected. 

...REMAINDER OF THE AREA...

A surface ridge prevails across the waters N of 20N W of 110W. 
Under the influence of the ridge, mainly moderate or weaker 
winds are observed by recent ASCAT scatterometer passes, with 
moderate seas in mixed swell. South of 20N, there are two 
tropical waves and a surface trough. The surface trough runs from
21N121W to 09N121W, while the tropical waves are near 99.5W and
132W as mentioned above. Any associated convection is described 
above. A 1008 mb low pressure area analyzed on the tropical wave
near 132W is supporting locally fresh winds and locally rough 
seas within about 150 nm in the northern semicircle. Moderate or 
weaker winds are elsewhere, locally fresh south of the ITCZ 
between 97W and 120W, along with moderate seas.

For the forecast, the National Hurricane Center (NHC) is 
monitoring several areas with the potential for tropical cyclone 
development across the eastern and central Pacific. Three of 
those disturbances are located in the eastern Pacific region. One
is a tropical wave a couple of hundred miles south of the coast 
of southern Mexico. Please, see the Special Features section for
more details. The second area is an area of low pressure located
well west-southwest of the Baja California Peninsula, which 
continues to produce disorganized showers and thunderstorms, 
primarily east of its center. This system is expected to move 
west-northwestward into less favorable environmental conditions 
during the next couple of days, and its development chances 
appear to be decreasing with a low chance of tropical cyclone 
formation in the next 48 hours, and also through 7 days. Finally,
an area of low pressure is expected to form by the middle of the
week several hundred nautical miles south of the coast of 
southern Mexico. Environmental conditions appear conducive for 
gradual development of this system thereafter, and a tropical 
depression could form by the end of the week or next weekend 
while it moves generally west-northwestward well offshore of 
Mexico. This system has a low chance of tropical cyclone
formation through 48 hours and a medium chance through 7 days.
Otherwise, expect little change except for freshening winds in
the northwestern open waters by the end of the week as the
pressure gradient tightens, resulting in building seas to rough.

$$
Lewitsky