000
AXPZ20 KNHC 221557
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1605 UTC Mon Mar 22 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 1200 UTC surface analysis and satellite imagery through
1500 UTC.

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

A surface trough extends from 10N84W to 04N100W. The
intertropical convergence zone continues from 04N100W to 03N120W
and from 03N132W to beyond 03N140W. As it is normal for this time
of year, a second ITCZ extends from 02S97W to 03S120W. Scattered
moderate convection is noted from 03N to 06N between 83W and 90W. 

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A recent altimeter satellite pass indicated seas to 8 ft between
Los Cabos and the Revillagigedo Islands this morning. This is 
likely due to in part to stronger winds off northern Baja 
California Sur, and longer period SW swell prevalent across the 
region. The fresh to strong NW winds are a result of fairly low 
pressure over the southwest U.S. and higher pressure farther west
of the eastern Pacific. Fresh to strong winds are likely active 
over parts of the central Gulf of California as well. Farther 
south, overnight gap winds through the Gulf of Tehuantepec have 
likely diminished. SW swell persist across the offshore waters of
southern Mexico as well. An upper level jet is supporting bands 
of clouds and possibly a few showers over the entrance to the 
Gulf of California.

For the forecast, expect fresh to strong NW winds to persist today
over the central Gulf of California and off northern Baja 
California Sur between deep low pressure over southwestern New 
Mexico and higher pressure over the eastern Pacific. These winds 
will diminish tonight, but mixed SW and NW swell in excess of 8 
ft will persist off Baja California Norte into mid week as a weak
cold front moves into the area. Winds and seas will diminish Wed
and Thu as the front dissipates. Looking ahead, another front 
will approach the region later in the week, supporting possible 
fresh to strong gap winds into the northern Gulf of California 
Thu night into Fri. Farther south, no gap wind events are 
expected in the Gulf of Tehuantepec the remainder of the week. 

Of note, the average date of the last Tehuantepec gale event is 
around April 9th. A couple of Tehuantepec gale events were
detected in May base on the latest 20 years of records. Within
this period, an average of 16 gale and 5 storm gap wind events 
is noted per cold season.

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

Fresh to strong winds are expected in the Gulf of Papagayo and 
downwind to about 90W through this morning, with seas to 8-9 
ft. Mainly gentle to moderate winds are forecast in the Gulf of 
Panama through Fri. Seas generated in the Tehuantepec region are 
still propagating across the offshore waters of Guatemala and El 
Salvador. This will diminish later today. Light to gentle winds 
will prevail elsewhere. 

Long period S to SW swell will maintain seas in the 4 to 6 ft 
range across the waters between Ecuador and the Galapagos 
Islands over the next several days.

REMAINDER OF THE AREA...

Strong 1037 mb high pressure system is centered north of the 
region near 36N140W. A pair of recent scatterometer satellite
passes indicated this pattern is supporting fresh to strong 
trade winds from 15N to 25N, west of 130W. The aerial extent of 
these winds will diminish late today as the high pressure weakens
some, and broad troughing west of the area dampens out. 

Long period NW swell dominates most of the forecast waters west 
of 115W while long period cross equatorial SW swell continue to 
propagate across the area east of 115W, reaching the coastal 
waters of Mexico, Central America, Colombia and Ecuador. 
Additional pulses of SW swell will continue to invade the region 
during the next several days.

Looking ahead, northerly swell in excess of 8 ft will move into 
the waters north of 25N later in the week, following a pair of 
weak cold fronts.

$$
Christensen