000
AXPZ20 KNHC 191609
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1605 UTC THU MAY 19 2016

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
1545 UTC.     
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

The monsoon trough axis extends from 09N84W to 07N93W to 08N100W
TO 07N109W. The ITCZ axis extends from 07N109W to 07N121W to
06N130W to 05N140W. Scattered moderate convection is within 180
nm south of the axis between 84W-97W...within 120 nm south
of the axis between 97W-100W and also within 60 nm of the axis
between 100W-105W.

...DISCUSSION...                                             

The main feature influencing the wind flow pattern over the
majority of the discussion area is a strong high pressure system
centered well northwest of the area near 43N146W, with a ridge
axis extending southeastward through 32N135W to 25N125W to near
19N115W. The pressure gradient between the ridge and the
ITCZ/monsoon trough to the southwest is supporting mainly
moderate to fresh trade winds. The high is expected to remain
relatively stationary and weaken over the next day or so. This
should result in trade winds weakening. First visible satellite
imagery shows what appears to be a rather diffuse weak surface
trough roughly along a position from 13N117W to 08N120W is
forecast to continue west around 10 kt. Only isolated
thunderstorms are within 120 nm either side of the trough of
from 09N-11N. near this trough is described above. Little change
is expected in the amount and intensity of convection near this
trough over the next two days as it continues in a westward
motion.

North-northeasterly swell that originated off the California
coast is responsible for seas to 9 ft north of 28N and west of a
line from 30N128W to 28N132W this morning. A deep-layered trough
building over the northeastern portion of the forecast area will
send a weak surface cold front into the northeast waters later
today and force the ridge westward. North-northwest winds behind
the front well north of the area will send a new batch of swell
into north waters Friday. This north-northwest swell will
subside overnight Friday night, with seas to 8 ft confined north
of 29N between 119W-122W by the end of the period Saturday
morning.

Scattered moderate to isolated strong convection is noted over
the eastern portion of the area from 11N to 16N between 93W-96W.
Precipitable water satellite imagery shows low-level moisture
increasing from the east throughout this area of the far eastern
pacific. In addition, an anticyclone aloft centered near 12N104W
extends a ridge axis eastward toward El Salvador. This favorable
upper pattern for deep convection is expected to change little
over the next two days, with clusters of convection developing
off and on during this time.

Gulf of California... 
Low pressure associated with the Gulf of California thermal trough is
forecast to set up over the far northern Gulf of California Friday
afternoon, with strong south to southwest winds and seas to 8 feet
within 60 nm of the low. Strong west to northwest winds are expected
west of the trough from 29N to 30.5N west of 114W at that time. These
winds will diminish to 10-15 kt by early on Sunday with seas subsiding
to 2-4 feet.

$$ 
Aguirre