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Eastern North Pacific Tropical Weather Discussion


000
AXPZ20 KNHC 131539
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sun Sep 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

...SPECIAL FEATURES...

Tropical Storm Norbert is centered near 18.2N 132.7W at 13/1500
UTC, moving west at 10 kt. Estimated minimum central pressure is
1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55
kt. Peak seas are 20 ft or 6.0 m. Numerous moderate to 
scattered strong convection is noted within 60 nm of the center.
Norbert is moving toward the west, and this motion is expected 
to continue during the next few days. Some fluctuations in 
intensity remain possible for the rest of the day, followed by a 
gradual weakening trend after that. Please read the latest HIGH
SEAS FORECAST issued by the National Hurricane Center at website
- https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest 
Norbert NHC Forecast/Advisory and Public Advisory at 
www.hurricanes.gov for more details.

Gale Warning south of Clarion Island (Invest EP97): An area of
1007 mb low pressure located several hundred nautical miles 
southwest of the southern tip of the Baja Peninsula near
17.5N116W continues to produce an area of disorganized showers 
and thunderstorms to the southeast of its center. Numerous
moderate and isolated to scattered strong convection is noted
within 300 nm in the SE quadrant and 540 nm in the SW quadrant of
the low. Associated winds are currently 20 to 25 kt with seas 
of 8 to 10 ft. Environmental conditions are expected to be 
generally conducive for development, and a tropical depression is
expected to form during the next couple of days while the system
moves generally westward. For more information on this 
disturbance, including gale warnings, please see High Seas 
Forecasts issued by the National Weather Service. This system has
a high chance of tropical cyclone formation within the next 48 
hours. A Gale Warning is in effect with this system. Regardless 
of tropical cyclone development, winds strong winds with rough 
seas are expected to the south and southwest of Clarion Island 
into Mon. Refer to the latest NHC Tropical Weather Outlook at 
website - www.hurricanes.gov for more details.

...TROPICAL WAVES...

A tropical wave is along 98W from 03N to 15N to just offshore and
southwest of Oaxaca, Mexico, moving west at around 20 kt. 
Associated convection is described below in the ITCZ/Monsoon 
Trough section.

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

The monsoon trough extends from 10N76W to 11N87W to 07N100W to
10N115W to 06N140W. In addition to the convection associated 
with T.S. Norbert and Invest EP97, scattered moderate convection 
is active from 03N to 12N to the east of 110W, and from 02N to
10N between 110W and 140W.

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

Please see the Special Features section for more information 
about Tropical Storm Norbert and Invest EP97. 

Fresh NW winds and seas to six feet are likely ongoing off Cabo
Corrientes, with fresh N gap winds across the Gulf of 
Tehuantepec. Elsewhere, and aside from the winds and seas already
described near Clarion Island, gentle to moderate breezes and 
3-5 ft seas prevail across Mexican offshore waters, with 1-3 ft
seas in the Gulf of California.

For the forecast, away from the impacts of Invest EP97, a ridge 
will build across the offshore waters of Baja California, 
bringing moderate to locally fresh NW to N winds through the 
early part of the week, locally strong Mon night. Expect fresh 
winds across the northern Gulf of California through the early 
part of the week due to the pressure gradient between the ridge 
and lower pressure over the Colorado River valley. Strong to 
near-gale N gap winds will pulse again in the Tehuantepec region
beginning Mon night, strongest beginning mid-week, with building
seas of 8 to 10 ft. Meanwhile, rough seas will build well 
offshore Baja California Norte tonight through Mon night.

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

High pressure north of the area is promoting fresh to strong 
easterly trade winds and locally rough seas across the Gulf of 
Papagayo region, extending downstream to near 90W. Elsewhere, 
moderate or weaker winds and moderate seas are prevalent, except
slight seas offshore Colombia and Panama. Convection continues 
to develop on either side of the monsoon trough. Gusty winds and 
higher seas are likely occurring near thunderstorms. 

For the forecast, the ridge north of the area will continue to 
support pulsing fresh to strong easterly winds and moderate to 
rough seas across the Papagayo region through early Thu. Moderate
to locally fresh N winds may pulse in the Gulf of Panama at night
into early Thu. Meanwhile, gentle to moderate southerly winds 
and moderate seas are expected over the waters between Ecuador 
and the Galapagos through mid-week. Gentle winds and moderate 
seas in long period SW swell are forecast elsewhere.

...REMAINDER OF THE AREA...

Please see the Special Features section for more information 
about Tropical Storm Norbert and Invest EP97.

Away from the impacts of T.S. Norbert, moderate to locally fresh
SE winds and rough seas are found south of 04N and west of the 
Galapagos Islands to about 134W. High pressure located north of 
area dominates the waters north of 24N. Under the influence of 
this system, and away from Norbert and Invest EP97, mainly 
moderate winds and moderate seas prevail, except fresh northerly
winds over the N-central waters extending from offshore Point
Conception, California.

For the forecast, Norbert will move to 18.6N 134.4W this evening,
19.0N 137.0W Mon morning, 19.4N 139.7W Mon evening, moving west
of the discussion waters and into the Central Pacific basin at 19.7N
142.4W Tue morning, weaken to a remnant low near 19.8N 145.1W 
Tue evening, and dissipate Wed morning. Elsewhere, a cross 
equatorial swell will persist over the next several days 
producing seas to 9 ft south of 04N. A tight pressure gradient 
will result in locally fresh N winds and rough seas in the
N-central/NE waters through the early part of the week. 

$$
Lewitsky