000
AXPZ20 KNHC 090942
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Tue Mar 09 2021

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 0600 UTC surface analysis and satellite imagery through
0930 UTC.

...SPECIAL FEATURES... 

Gulf of Tehuantepec Gale Warning: The combination between strong
high pressure over eastern Mexico and lower pressure south of 
Mexico continues to keep a very tight pressure gradient in place
over southeastern Mexico. This synoptic set-up is sustaining a 
gap wind event of strong gale force N to NE winds over the 
Tehuantepec region as was noted in an ASCAT pass from last 
night. As the high pressure begins to shift eastward on Wed,
this will allow for the gradient to begin to relax. As a result,
the strong gale force winds will respond by diminishing to 
strong speeds Wed afternoon. These winds may briefly pulse up 
to near gale force late Wed night, then significantly diminish
on Thu.

Presently, seas churned up by these gale force winds are in the 
range of 12-19 ft. These seas will change today, then begin to 
slowly subside tonight through Wed night. It is urged that 
mariners transiting the Gulf of Tehuantepec region should 
exercise caution through tonight to avoid possible hazardous 
conditions that may come forth due this event. Please read the 
latest NWS High Seas Forecast issued by the National Hurricane 
Center at website: 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

Potential for Heavy Rainfall in Western Colombia: Latest GOES-16  
imagery shows abundant atmospheric moisture over the eastern
Pacific waters S of 20N and E of about 90W. Scattered showers and 
isolated thunderstorms are observed over these waters, while
numerous showers and thunderstorms, with frequent lightning are 
noted along and inland the NW coast of Colombia extending to 
the southern section of Panama. This activity extends well inland
NW Colombia, and is likely producing very heavy rainfall.
Upper-level divergence is quite prevalent over these areas as a 
wet pulse of the Madden Julian Oscillation is in play as well. 
With these factors in place, expect for shower and thunderstorm 
activity to become quite numerous along and near the coast of 
Colombia today, with this trend of enhanced precipitation likely 
to last last through the end of the week. Mariners near and
offshore the coast of Colombia are advised to be aware of the 
possibility of reduced visibility from the heavy rain produced by
this activity. Please refer to forecasts and bulletins issued by
your National Meteorological Service for more details.

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

A trough axis extends from NW Colombia southwestward to 07N78W 
to 03N90W to 02N99W and to 03N109W, where overnight scatterometer
data indicates that it transitions to the ITCZ to 04N118W to 
02N130W and to beyond the area at 03N140W. Scattered moderate 
convection is within 60 nm north of the ITCZ between 109W-113W, 
and also within 30 nm of the ITCZ between 125W-129W and between 
134W-139W.

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

See the Special Features section above regarding an ongoing 
Gale Warning for the Gulf of Tehuantepec region.

Moderate to locally fresh NW winds west of the Baja California 
peninsula will increase to fresh to strong speeds this afternoon
north of Cabo San Lazaro, then shift to south of Cabo San Lazaro 
Thu through Sat. A set of large NW swell has begun to impact the 
offshore waters. It will begin to decay Thu night through Fri 
night allowing the seas to subside to 8-9 ft.

Light to gentle variable winds in the Gulf of California will 
shift to NW to N moderate to locally fresh early on Wed. Moderate
to fresh winds along the southern half of the Gulf of California
will increase to fresh to strong late Fri. Otherwise, gentle to 
moderate winds will prevail over the offshore waters west of 
southern Mexico, except in the vicinity of the Gulf of Tehuantepec.

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

Fresh to strong NE to E winds will continue across the Papagayo 
region through the end of the week, with winds reaching near 
gale force late at night and into the morning hours through Wed.
Seas associated with these winds will build to 8-10 ft as strong
high pressure builds over the western Caribbean Sea. Fresh to 
locally strong northerly winds are forecast in the Gulf of Panama
through Wed. Light to gentle winds, with seas in the 3-5 ft 
range due to a S to SW swell will prevail elsewhere through the 
end of the week.

REMAINDER OF THE AREA...

Strong high pressure ridging stretches east-southeastward to near 
18N106W. The gradient between this ridge and lower pressure S of
20N is supporting fresh to strong NE to E winds between the ITCZ
and 20N and W of about 125W. Seas within this area are in the 
8-11 ft range due to long-period NW to N swell. This area of 
swell will gradually shift east-southeastward through Thu as 
a cold front moves across the NW part of the area.

A large set of long-period NW to N swell over the NW forecast 
waters is producing seas there of 10-12 ft. This set of swell 
will gradually propagate as far S as 03N and W of about 112W by 
Wed night as the area of trade winds expands some to the N. By
that same time, yet another set of NW to N swell will be moving 
through the northern waters, where even higher seas peaking to 
around 13 ft near 30N are expected, before subsiding at the end 
of the week.

$$
Aguirre