000
AXPZ20 KNHC 040827
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Mon Dec 4 2023

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
0800 UTC.

...SPECIAL FEATURE...

Gulf of Tehuantepec Gale Warning: Strong high pressure is
building over central Mexico, supporting a surge of northerly gap
winds reaching gale force across the Gulf of Tehuantepec this
morning. This pattern will persist through much of week, with
gales continuing mainly at night through Thu night. Seas may 
reach 10 to 12 ft downstream of the strongest winds during the 
overnight hours. 

Please read the latest High Seas Forecast issued by the National
Hurricane Center at 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

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

The monsoon trough extends from 10N86W to 06N95W to 06N115W. The
ITCZ extends from 06N115W to 09N135W to beyond 09N140W. Scattered
moderate convection is evident from 12N to 14N between 103W and
107W, and from 08N to 10N between 130W and 140W. 

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

A broad ridge extends across the offshore waters of Baja 
California from 1028 mb high pressure near 31N129W to the
Revillagigedo Islands. The pressure gradient between the ridge and
a trough located along the eastern shore of the Gulf of 
California supports fresh to strong NW to N winds over the 
central and southern Gulf of California, with 4 to 6 ft seas. The
pattern is also supporting mainly moderate NW to N winds off 
Baja California, where combined seas are 6 to 8 ft in NW swell. 
Farther south, light breezes persist off southern Mexico, with 3 
to 5 ft combined seas in mixed swell.

For the forecast, besides the gap wind event in the Gulf of Tehuantepec
described in the Special Features section above, long- period NW
swell persist off Baja California and the Revillagigedo Islands 
through mid week. Looking ahead, reinforcing NW swell will arrive
off Baja California Norte by Fri, accompanying a cold front 
moving into the region.

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

A recent scatterometer satellite pass confirmed fresh NE to E 
winds blowing across the Gulf of Papagayo. Seas are 5 to 6 ft in
this area. Gentle to moderate winds are noted elsewhere, with 4 
to 6 ft seas primarily in SW swell.

For the forecast, high pressure building north of the region 
will support moderate to fresh gap winds across the Gulf of 
Papagayo and off Nicaragua through the week, pulsing to strong at
times mainly at night. Seas will build well offshore of 
Guatemala by Tue due to swell generated by gale-force gap winds 
in the nearby Gulf of Tehuantepec. Gentle to moderate winds are 
forecast elsewhere. Moderate combined seas will persist through 
mid week in a mix of SW and NW swell. 

...REMAINDER OF THE AREA...

High pressure dominates the waters north of 20N. Recent 
scatterometer satellite data confirmed a large area of fresh to 
strong trade winds south of the ridge, mainly from 10N to 20N 
west of 115W. Concurrent altimeter satellite data showed combined
seas in this region were 10 to 14 ft, in a mix of locally seas 
due to the trade wind flow, and longer-period NW swell. Combined 
seas of 8 to 10 ft cover much of the region elsewhere west of 
110W, although with primarily S to SE swell south of 10N. Gentle 
to moderate winds and 5 to 7 ft seas are noted east of 110W.

For the forecast, the high pressure will dissipate early in the
week ahead of a cold front moving eastward across the waters 
north of 25N Tue through Thu. This will allow trade winds to 
diminish slightly west of 110W through mid week. Combined seas 
will also subside slightly into the early part of the week, 
although this will be countered by large, long- period NW swell 
accompanying the front across the waters north of 10N and west 
of 120W through mid week. East of 110W, by Thu, the combination 
of the NW swell with shorter- period NE swell emerging from gap 
wind events and fresh E trade winds will support rough seas from 
07N to 12N between 95W and 110W.

$$
Christensen