000
AXPZ20 KNHC 201602
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Sat Nov 20 2021

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
1545 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: The pressure gradient between 
high pressure building along eastern Mexico and lower pressure 
within the eastern north Pacific monsoon trough is supporting 
gale-force north to northeast winds across the Gulf of 
Tehuantepec. The gale-force winds will continue through late 
this morning before diminishing. Winds will be near gale-force 
through late tonight. Seas will peak near 12 ft tonight. The 
gradient will slacken enough on Sun to allow for the winds to
diminish to strong speeds, however, beginning on Mon a
re-tightening of the gradient is expected to boost winds up to 
near gale-force, reaching to gale-force on Mon night. Please
see the latest NWS High Seas Forecast issued by the National 
Hurricane Center at 
website://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more 
information.

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

The monsoon trough axis extends from northwestern Colombia to 
across central Costa Rica to 10N85W to 07N92W and 08N102W, where 
overnight scatterometer data indicates that it transitions 
to the ITCZ to 09N108W to 09N119W to 10N132W and to beyond
10N140W. Scattered moderate to strong convection is seen within
180 nm north of the ITCZ between 124W-128W. Scattered moderate
to isolated strong convection is within 120 nm north of the 
ITCZ between 112W-117W, and within 60 nm of the ITCZ between
118W-124W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO

Please see the Special Features section above for details on
the latest Gulf of Tehuantepec gale-force gap wind event.

Gale force winds, and seas to 12 ft, prevail over the Gulf of 
Tehuantepec. Elsewhere, a ridge extends from high pressure of 
1024 mb near 30N130W southeast to the west of the Baja California
peninsula. Gentle to locally moderate winds prevail over the 
open waters off Mexico, with light to gentle winds prevailing 
over the Gulf of California. Seas are in the 4-5 ft range over 
the open waters off Mexico, with 1-3 ft seas over the Gulf of 
California. 

For the forecast, gale-force winds will continue across the Gulf
of Tehuantepec region through late this morning. then diminish to 
strong speeds. Gap winds may once again approach gale-force 
again in the Gulf of Tehuantepec region early next week as strong
high pressure surges southward over eastern Mexico. Fresh to 
strong northwest to north winds may develop in the northern Gulf 
of California early next week. Fairly tranquil conditions are 
forecast elsewhere through the weekend and into early next week. 
Fresh northwest winds are expected offshore Baja California Norte
during the middle of next week. 

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

Fresh to strong northeast to east winds remain over the Papagayo
region. Otherwise, light to gentle winds are noted north of the 
monsoon trough. Gentle to moderate southerly winds prevail south 
of the monsoon trough. Seas are in the 4-6 ft range over the
waters south of Costa Rica, and 5-7 ft over the waters north 
of Costa Rica except for higher seas of 6-9 ft north of El
Salvador due to a northwest swell originating from the Gulf of 
Tehuantepec region.

For the forecast, the fresh to strong northeast to east winds in
the Papagayo region will diminish to mainly fresh speeds by 
early this afternoon, then pulse back up to fresh to strong 
speeds once again early on Sun, then remain at moderate to fresh 
speeds thereafter. Gentle to moderate winds will prevail across 
the rest of the area the next several days. The northwest swell
that is producing seas of 6-9 ft north of El Salvador will
gradually lower through Sun night allowing for those seas to 
subside to 4-6 ft. These seas may build some again early next 
week as gale-force winds start up again in the Gulf of 
Tehuantepec region.

REMAINDER OF THE AREA...

Broad high pressure ridging covers the area north of about
16N and west of 115W. A surface trough extends from 17N132W to 
10N134W. The pressure gradient between the area of high pressure 
and the surface trough is supporting fresh to strong winds, and 
seas 8-9 ft over the northern portion of the trough. Moderate to 
fresh east winds prevail elsewhere from 10N to 20N between 120W 
and 140W. Light to gentle winds are in the vicinity of the high 
center. Gentle to moderate winds are elsewhere north of the ITCZ.
Gentle to moderate southerly winds are south of the monsoon 
trough and ITCZ. Seas of 5-7 ft are observed over the waters 
within the moderate to fresh winds. Elsewhere, seas of 4-6 ft 
prevail. 

For the forecast, the area of fresh to strong east winds between
the trough and the area of high pressure will diminish to mainly
fresh speeds by early on Sun, with seas to 8 ft in mixed swell.
 
$$
Aguirre