000
AXPZ20 KNHC 190231
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 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 0000 UTC surface analysis and satellite imagery through
0200 UTC.     
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

The monsoon trough axis extends from 1009 mb low pressure over
Colombia near 09.5N75W to 09.5N84W to 06.5N95W to 08N104W...
where it transitions to ITCZ...continuing on to 09.5N114W to
08N130W to beyond 06N140W. Scattered moderate to strong
convection is noted from 05N-10N between 79W and 107W. Scattered
moderate TO strong convection is noted within 180 nm N of the
ITCZ from 108W-117W. 

...DISCUSSION...                                             

A broad surface ridge dominates much of N and NW portions of the
area this evening. A 1037 mb high pressure center was located
over the eastern North Pacific well to the northwest of the area
near 42N149W, with a ridge axis extending southeastward through
30N134W to 20N117W then weakly to near 12N100W. The pressure
gradient between the ridge and the ITCZ to the south is
supporting mainly moderate to fresh trade winds south of 22N and
west of 120W. Strong NE winds occurring along with and northwest
of a surface trough across the tropics shifted west of 140W
earlier this afternoon. However residual NE wind waves are
mixing with SW well behind the exiting trough to produce an area
of 7-8 ft seas from 11N-17N west of 130W.  The subtropical high
will shift northeastward over the next 24 hours causing the
ridge axis to shift west and weaken as deep-layer troughing
builds over the southwestern United States and across the
northeast waters. This will cause this area of fresh trade winds
north of the ITCZ to diminish in coverage. 

The pressure gradient between the ridge and lower pressure
across interior Mexico is also producing moderate northwesterly
winds extending along the entire length of Baja California and
southeastward across the near and offshore Mexican coastal
waters to near Acapulco. Recent observations and global models
indicate that these winds will be enhanced along the prominent
points along the coastlines, namely along Cabo San Lucas in
southern Baja California and around the Cabo Corrientes region,
where winds around 20 kt and seas 6-8 ft will prevail through
early morning Thursday, before diminishing.

Northwesterly to northerly swell that originated off the
California coast is producing seas to 8 ft just to the north of
30N between 128W-134W this evening. This northerly swell is
producing seas of 5-6 ft along much of the Pacific coastal
waters of Baja California. The aforementioned deep-layered
troughing building over the northeastern portion of the forecast
area will send a weak frontal boundary across the NE waters and
portions of Baja California Norte Thursday night. This will
increase northerly winds along the California coastal waters and
send NW swell moving into the NE waters Thursday and Friday.
Global models also indicate a weak low pressure center
developing with this frontal boundary across the far northern
Gulf of California. S to SW winds 20-25 kt are expected to
develop south and east of this low center by Friday evening.

Abundant low level moisture has converged about the monsoon
trough across eastern portions of the area east of 104w...where
unstable atmospheric conditions are leading to large clusters of
moderate to strong convection described above. Conditions are
forecast to remain favorable for sustained convection across
this area through early Friday as this active weather shifts
gradually westward. 

$$ 
Stripling