000
AXPZ20 KNHC 180340
TWDEP

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Thu May 18 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 0000 UTC surface analysis and satellite imagery through
0320 UTC.

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

The monsoon trough extends from 09N83W to 08N98W. The ITCZ 
extends from 08N98W to 03N130W to beyond 04N140W. Scattered 
moderate isolated strong convection is noted from 02N to 09N
between 94W and 115W, and from 01N to 05N between 131W and 140W.

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

Weak high pressure ridging extends from NW to SE across the
offshore waters of Mexico. Gentle to moderate NW winds are noted
to the west of the Baja California peninsula. Gentle to moderate
S winds are over the Gulf of California, except for moderate to
locally fresh SW winds near the Cabo San Lucas area. Mainly 
light to gentle winds are noted elsewhere, except for moderate NW
winds near Cabo Corrientes. Seas are mainly 6-8 ft over the open
waters off Mexico in primarily S-SW swell. Seas are 3 ft or less
in the Gulf of California, except 3-6 ft in the far southern Gulf
of California. Seasonally hazy conditions persist from near the 
coast to offshore of Guerrero and Michoacan with reductions to 
visibility around 5 nm per recent coastal observations.

For the forecast, fresh to strong N-NE winds will pulse in the 
Gulf of Tehuantepec during the late night/early morning hours 
starting late Fri night. Winds may pulse to fresh to locally 
strong in the southern Gulf of California and near Cabo San Lucas
tonight and again Sun night, and near Cabo Corrientes Fri night 
through Sat night due to localized tight pressure gradients. 
Mainly gentle to moderate winds will prevail elsewhere and 
otherwise. SW swell with seas of 7-8 ft offshore Mexico will 
gradually subside through tonight. Seas of 4-7 ft will prevail 
for the remainder of the forecast period. Reduced visibilities in
haze are possible in the S and SW Mexico offshore waters due to 
smoke produced by agricultural fires. 
 
...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA,
AND WITHIN 750 NM OF ECUADOR...

Gentle to moderate S winds are occurring between Ecuador and the
Galapagos Islands. Moderate N winds are in the Gulf of Panama. 
Elsewhere, light to gentle winds prevail. Seas of 5-6 ft prevail 
in S-SW swell, except up to 7 ft south of the Galapagos Islands.
Seasonally hazy conditions persist from near the coast to 
offshore of Nicaragua northwestward, with reductions to 
visibility around 5 nm possible.

For the forecast, offshore winds will pulse to fresh to locally
strong in the Papagayo region during the late night and early 
morning hours starting late Thu night through Sat night.
Southerly winds between Ecuador and the Galapagos Islands will
increase to moderate to locally fresh late Thu through early Fri. 
Otherwise, gentle to moderate winds will prevail across the 
waters. A new set of S-SW swell will arrive across the Ecuador to
Galapagos Islands waters late tonight, building seas to 7-10 ft 
through Fri night before decaying slightly thereafter. Reduced 
visibilities in haze are possible from the Guatemala to the
Nicaragua offshore waters due to smoke produced by ongoing 
agricultural fires. 

...REMAINDER OF THE AREA...

High pressure of 1018 mb is centered near 26N132W. The pressure 
gradient between the area of high pressure and lower pressure 
within the ITCZ is supporting moderate to fresh trades N of the 
ITCZ to 13N and west of 128W. Light to gentle winds are in the 
vicinity of the high center. Moderate to locally fresh SE to S
winds are south of the ITCZ between 95W and 110W. Gentle to 
moderate winds are noted elsewhere. Seas are in the 6-8 ft range 
mainly in southerly swell across most of the discussion waters.
The exception is the NW corner of the area, where a predominantly
NW swell is raising seas to 7 to 8 ft north of 25N and west of
135W.

For the forecast, the set of NW swell over the NW waters will 
decay by early Thu. Meanwhile, the southerly swell will subside 
across the remainder of the waters tonight. A new set of 
southerly swell with seas of 7-10 ft will cross 03.4S late 
tonight, mainly east of 120W. This swell will spread seas of 8 
ft or greater as far north as 07N by early Fri before seas 
gradually subside Fri night into the weekend.

$$
Hagen