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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 262134
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Sat Sep 26 2020

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
2100 UTC. 

...TROPICAL WAVES...

The axis of a tropical wave is near 95W N of 03N, moving 
westward at 10 kt. Scattered moderate to isolated strong 
convection is from 10N to 16N between 90W and 100W. 

The axis of a tropical wave is near 106W N of 03N, moving 
westward at 10 kt. Scattered moderate convection is from 09N to 
13N between 100W and 106W.

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

The monsoon trough extends from 11N86W to 12N100W to 11N120W to 
11N140W. Scattered moderate convection is from 04N to 10N between
85W and 90W.  

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A weak ridge west of Baja California will maintain gentle to 
moderate NW to N winds across the region. Northwesterly swell 
propagating across the waters off Baja California Norte will 
spread southward to the remainder of the Baja California offshore
waters through tonight. This swell event will begin to subside 
Sun into Mon. Light to gentle winds are expected farther south 
the next several days. 

Gulf of Tehuantepec: A gale to near strong force gap wind event 
is possible in the Gulf of Tehuantepec by the middle of next 
week. Currently, marine guidance suggests N winds of 30 to 45 kt
and seas building up to 16 or 17 ft by Tue night.

Of note, the 20-year climatology of the Tehuantepec gap wind
events indicates that on average 16 gale-force events and 5 
storm-events occur in the Gulf of Tehuantepec per cold season. 
Most gale-force events occurred during November and December, 
while most storm-force winds occurred in January. Based on latest
model trends and the present evolving synoptic scale setup, it
appears that the forecast gale to near strong force wind event 
may replace the previously recorded earliest start date of 
October 3rd.

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

Moderate southerly flow prevails S of the monsoon trough, with 
gentle winds north of the monsoon trough. Combined seas are 
currently 5 to 7 ft in a mix of wind waves and southerly swell. 
Long period SW swell will impact the waters between Ecuador and
the Galapagos Islands on Sun, building seas to 8 ft. This swell 
event will continue to propagate northward reaching the offshore
waters of Central America by early next week, with seas building
to 6 to 8 ft.

REMAINDER OF THE AREA...

The remnant low of former tropical cyclone Lowell is centered
near 21N135W. The cyclonic circulation remains well defined with
mainly low clouds associated. A recent scatterometer pass 
provides observations of fresh to strong winds in the northern
semicircle of the low center, particularly from 21N to 27N W of
131W. Seas continue to peak near 14 ft based on altimeter data, 
in a combination of locally generated seas mixing with long 
period NW swell. The remnant low will continue to shift westward,
moving west of the area late Sun. Seas in the vicinity of the 
remnant low will remain in the 8 to 12 ft range on Sun. Conditions
will improve early next week as the remnants of Lowell shift W 
of 140W and as the remaining northerly swell decays.

Southerly swell will begin to propagate N of the equator to
night, building seas to 8-10 ft between 100W and 120W by Sun
night into Mon. Seas will gradually subside across the waters S
of 20N and E of 120W Tue through Wed.


$$
GR