000
AXPZ20 KNHC 182139
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED MAY 18 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 1800 UTC surface analysis and satellite imagery through
2100 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-11N between 78W and 91W...and from
04.5N-10N between 91W and 105W. Widely scattered moderate
isolated strong convection is noted within 210 nm N of the ITCZ
from 106W-128W. 

...DISCUSSION...                                             

A broad surface ridge dominates much of W and NW portions of
the area late this afternoon. A 1037 mb high pressure center was
located over the eastern North Pacific well to the northwest of
the area near 42N148W, with a ridge axis extending southeastward
through 30N133W 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 20N and
west of 115W. Strong NE winds occurring along with and northwest
of a surface trough across the tropics have shifted west of
140Wthis afternoon. However residual NE wind waves area mixing
with SW well behind the exiting trough to produce an area of 7-
9ft seas from 10N-16.5N west of 128W.  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 the area of fresh trade winds to
diminish in coverage. 

The pressure gradient between the ridge axis and lower pressure
across Mexico is also producing moderate northwesterly winds
extending from central Baja California southeastward across the
near and offshore Mexican coastal waters to near Acapulco.
Recent observations and global models indicate that these winds
will be enhance along the prominent points along the coastlines,
along Cabo San Lucas in southern Baja California and around the
Cabo Corrientes areas, where winds around 20 kt and seas 6-8 ft
will prevail this evening 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 126W-130W this afternoon. 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
Thursday night. This will increase northerly winds along the
California coastal waters and send NW swell moving into the NE
waters Thursday and Friday. 

Abundant low level moisture has converged about the monsoon
trough across eastern portions of the area...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