169 
AXPZ20 KNHC 080958
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat Apr 08 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
0945 UTC.

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

A surface trough extends from NW Colombia southwestward to 
the coast at 07N78W and continues to 08N86W to 03N99W and to 
03N112W, where overnight scatterometer data indicates that it 
transitions to the ITCZ and continues to 04N122W to 04N130W and 
to beyond 03N140W. Numerous moderate to strong convection is seen
within 120 nm north of the ITCZ between 121W-126W. Scattered
moderate to isolated strong convection is within 60 nm south of 
the ITCZ between 126W-130W. Scattered moderate convection is 
within 120 nm north of the trough between 84W-87W, also within
60 nm south of the trough between 87W-90W and within 60 nm north
of the ITCZ between 126W-138W.

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

The subtropical ridge continues well to the west of the Mexican
offshore waters. An overnight ASCAT data pass suggest that gentle
to moderate northwest to north winds are offshore Baja
California. Fresh northwest winds are offshore Baja California
north of 29N. Seas over these waters are in the 4-6 ft range. 
Light to moderate northerly winds and seas of 2-4 ft are over 
the Gulf of California. Moderate or weaker winds and moderate 
seas prevail in the remaining offshore waters of Mexico, 
including the Gulf of Tehuantepec.

For the forecast, mainly moderate northwest to north winds and 
moderate seas will remain over the offshore waters of Baja 
California through the weekend and into early next week. Fresh to
strong gap winds will pulse in the Gulf of Tehuantepec late at 
night and diminishing in the afternoons through the forecast 
period. Wind speeds to gale-force are possible on Tue night and 
are expected to reach to near gale on Mon night. Seas will exceed
8 ft with these winds.

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

The earlier fresh east to southeast winds in the Gulf of 
Papagayo region and over the waters within 60 nm offshore 
southern Nicaragua have become fresh to strong northeast to east
winds during the overnight hours. This occurred just after an 
ASCAT pass had showed the fresh winds. Seas with the current 
fresh to strong winds are in the 5-7 ft range. Farther east, 
moderate to fresh northerly winds are in the Gulf of Panama along
with seas of 4-6 ft. Per latest ASCAT data passes, light to 
gentle winds are elsewhere over these waters. Moderate seas are 
over these waters as well.

For the forecast, the fresh to strong northeast to east gap 
winds in the Gulf of Papagayo will diminish to fresh speeds this 
afternoon. These winds will pulse back up to fresh to strong 
speeds at night and into the early afternoons through Mon. Gentle
to moderate winds will continue elsewhere along with a moderate 
long-period southerly swell, except in the Gulf of Panama where 
fresh northerly winds are expected through Tue night. Scattered 
showers and thunderstorms are offshore Costa Rica. This activity 
is likely to continue through the weekend. 

...REMAINDER OF THE AREA...

A 1023 mb high pressure is analyzed near 27N128W. The pressure 
gradient between the high pressure and lower pressure in the 
vicinity of the ITCZ is supporting mainly fresh northeast to 
east trade winds north of the ITCZ to about 22N and west of 118W 
as depicted in an overnight ASCAT data pass over that part of 
the area. These winds combined with a long-period northerly 
swell are resulting in seas of 8-10 ft. Light to gentle east to 
southeast winds are south of the ITCZ. Seas there are 5-7 ft due 
to the northerly swell. 

For the forecast, the moderate to fresh northeast to east 
trade winds will change little through the weekend, then begin
to diminish in coverage some starting Mon. The northerly swell
will gradually decay through the weekend allowing for the
aforementioned 8-10 ft seas to subside to less than 8 ft late
Sun night into early on Mon. The tail-end of a weak cold front 
that presently reaches southwestward from 31N130W to 30N137W will
sag eastward along 30N today. The gradient is weak near this 
front allowing for light to gentle winds near it. Seas near it 
are 4-6 ft due to a long-period northwest swell.

Looking ahead, the aforementioned high pressure will weaken some
as it shifts eastward through early Mon in response to a cold 
front that is expected to approach 30N140W by that time. The 
front is expected to weaken early next week as it moves over the 
north-central and northeast waters and as strong high pressure 
ridging builds east-southeastward over those same waters. A 
large set of northwest swell inducing seas of 8-10 ft will begin 
to intrude into the far northwest waters early on Mon.

$$
Aguirre