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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 132204
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2038 UTC Tue Nov 13 2018

Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery through
2115 UTC. 

...SPECIAL FEATURES...

Gulf of Tehuantepec Storm Warning: Strong high pressure over the
Gulf of Mexico is generating gale force winds over the Gulf of 
Tehuantepec. The winds will quickly increase to storm force this 
evening. Seas downstream of the Gulf of Tehuantepec are expected 
to build to 13-22 ft by late tonight and Wed. Storm force winds 
are expected to continue through late Wed night, with gale force 
winds then continuing into early Sat morning. A large swath of 
high seas from this event will propagate south and southwest of 
the Gulf of Tehuantepec region, with the leading edge of the 8 ft
seas forecast to reach near 108W by Fri.

Gale Warning west of northern Baja California: Strong high 
pressure building across the SW United States and Mexico is 
supporting strong N winds over the Gulf of California through 
Wed morning. The winds are funneling through the mountain 
passages over Baja California Norte will support minimal gale 
force NE winds over the waters within 30 nm of the Baja Peninsula
from 28N to 29.5N E of 115W this evening. Strong to near gale 
force northeast winds and building seas of 8 to 10 ft are also 
expected across the offshore forecast waters west of Baja 
California, mainly N of Cabo San Lazaro through Wed morning.

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

The monsoon trough axis extends from 10N73W to 09N82W to 07N90W 
to low pres 1011 mb near 07N95W to 09N112W. The ITCZ axis extends
from 09N125W to 10N130W to beyond 07N140W. Scattered moderate 
and isolated convection is seen from 04N to 10N E of 82W, from 
06N to 10N between 92W and 98W, from 08N to 11N between 103W and 
123W and from 07N to 10N W of 136W.

 ...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section for the Gulf of 
Tehuantepec storm event and a gale event winding down along the 
west coast of Baja California Norte.

Gulf of California: The pressure gradient associated with strong
high pressure over the Great Basin of the United States is 
bringing strong NW to N winds over the northern and central Gulf.
Seas up to 8 ft are present N of 30N. Winds and seas will start 
to subside Wed morning as the high slides SE and weakens.

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

Fresh northeast winds will pulse over the Gulf of Papagayo 
today, then diminish to moderate to fresh tonight. Winds will 
become fresh to strong by late Wed night as a tight pressure 
gradient develops over northern Central America behind a strong 
cold front that will move across the northwestern Caribbean Sea. 
Seas are forecast to build to 9 ft by Thu morning. This gap wind 
event will expand and continue through the upcoming weekend.

A strong Tehunatepec gap wind event west of the area is forecast
to spread strong to near gale force winds and building seas of 
12 to 18 ft into the Guatemala and El Salvador offshore waters, 
mainly to the west of 92W, tonight through Thu morning.

Otherwise, light to gentle winds are forecast N of the monsoon 
trough, with gentle to moderate SW winds S of the trough for the 
next several days. Cross-equatorial long period SW swell will 
keep seas around 6-7 ft from Ecuador and the Galapagos Islands 
to near the Azuero Peninsula through Wed.

REMAINDER OF THE AREA...  

High pressure centered W of California near 33N129W ridges 
SE to near the Revillagigedo Islands. The pressure gradient 
between the high and low pressure in the vicinity of the ITCZ 
will support fresh to locally strong trades just north of the 
ITCZ. Seas of 8 to 9 ft will be associated with these winds 
covering roughly the waters from 10N to 16N W of 120W today, 
shifting to 10N-15N between 122W and 126W. These conditions are 
forecast to last through Thu, while they shift westward and 
decrease in coverage. 

Model guidance depicts a cold front approaching the far 
northwest corner of the area on Fri. NW swell associated with the
dissipating stationary front is forecast late tonight and early 
Wed, with seas of 8-10 ft covering much of the waters north of 
07N and west of 130W by early Thu as the swell merges with waves 
generated by the area of fresh to strong trades.

Cross equatorial SW swell of 7 to 9 ft will propagate across the 
waters south of 06N between 100W and 116W through tonight, then 
shrink south of 01N between 113W and 121W by Wed night.

$$
CAM