000
AXPZ20 KNHC 150352
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Tue May 15 2018

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 0000 UTC surface analysis and satellite imagery through
0215 UTC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

The monsoon trough axis extends from Colombia near 09N75W to low
pressure over the far southwestern Caribbean at 11N81W and 
across northern Panama to 09N95W to 11N106W to 14N112W to low
pressure near 12N116W 1010 mb to 07N123W, where latest
scatterometer data indicated that it transitions to the
ITCZ to 04N134W. Scattered strong convection is noted within 
60 nm north of the trough between 113W and 115W and within 30 nm
of the trough between 115W and 116W. Scattered moderate to strong
convection is within 360 nm south of the trough between 107W and
111W and within 180 nm south of the trough between 105W and 
107W. Scattered moderate convection is within 180 nm south of the
trough between 85W and 88W, also within 150 nm south of the 
trough between 114W and 117W and within 120 nm south of the 
trough between 94W and 99W. 

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

A NW to SE oriented high pressure ridge prevails across the 
offshore waters west of Baja California, producing gentle to 
moderate NW winds over those waters. These winds are expected to
freshen late tonight through Wed, then become fresh to locally 
strong Wed night as the ridge strengthens slightly. Altimeter 
data from this evening indicated that seas were just below 8 ft, 
in the 5-7 ft range. They will change little through late Tue 
before building slightly on Wed to 6-8 ft in mixed SW swell with 
fresh NNW wind swell.

The gradient offshore Baja California will tighten more than 
what it has been during the past several days as the above
mentioned ridge strengthens. This will lead to NW winds offshore
most of the peninsula to increase to strong speeds beginning 
late Wed afternoon or evening, with seas remaining at 6-8 ft. 
Model guidance indicates that these winds will continue through 
Thu night.

Gulf of California: S to SW winds of around 15-20 kt over a 
small section of the northern Gulf of California from 30N to
30.5N W of 113W will become light and variable Tue.  Gentle to 
moderate NW winds will continue across the remainder of the Gulf 
through Wed, except for fresh NW winds along the Mexico coast 
from 24N to 26N Tue evening through Wed evening.

Gulf of Tehuantepec: Winds have become light to gentle S to SW in
direction. Winds will again become moderate to fresh from the 
N and NE late this afternoon and through tonight, but briefly 
before they become gentle S to SW winds on Wed. This cycle of 
changing winds will continue through Thu as a weak pressure
pattern remains over Mexico.
  
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR... 

Gulf of Papagayo: Light to gentle winds will dominate the gulf 
most of the forecast period with seas of 5-6 ft diminishing 
slightly on Tue to 4-5 ft in long period SW swell. A strong pulse
of cross equatorial SW swell will move into the regional waters 
beginning Wed, and build seas to 5-7 ft Thu through Sat. 
  
Gulf of Panama: Gentle to moderate S to SW winds are forecast 
during the next several days, with seas of 4-6 ft in long period 
southerly swell, building to 5-7 ft Wed night through Sat as 
long period SW swell reaches the coasts of Panama and Colombia.

Elsewhere, gentle to moderate southwest winds are expected to 
the south of the monsoon trough with axis roughly along 09N/10N,
with light to gentle variable winds north of trough. Seas are 
forecast to build to 6-7 ft in long period SW swell between 
Ecuador and the Galapagos Islands beginning on Wed. 

REMAINDER OF THE AREA...

A ridge extends from the NW waters southeastward to near the 
Revillagigedo Islands. The pressure gradient between the ridge 
and the monsoon trough and ITCZ to the south is presently weak, 
and yielding moderate NE-E trade winds between about 10N and 22N
to the west of 110W. Seas across this tradewind belt are 
expected 7-9 ft this afternoon and will subside to 6-8 ft tonight
through Wed. The ridge will shift slightly SE through Wed and 
increase winds across the tradewind belt ever so slightly before 
new high pressure shifts SE into N portions of the discussion 
area Thu and increases trade winds to fresh to strong. Seas are 
expected to increase to 7-9 ft Thu into Fri.

Decaying NW swell is propagating through the waters north of 20N 
between Baja California and 120W, where seas are peaking at 7-8 
ft. These seas will subside to less than 8 ft late tonight and
change little through Thu.

$$
Aguirre