000
AXPZ20 KNHC 011546
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1605 UTC SUN MAY 01 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... 

A SURFACE TROUGH EXTENDS FROM 08N85W TO 08N100W TO 06N109W TO
07N120W. ANOTHER SURFACE TROUGH STRETCHES FROM 06N124W TO
11N123W. THE ITCZ AXIS REACHES FROM 05N127W TO 03N135W TO
04N140W. SCATTERED MODERATE CONVECTION IS PRESENT WITHIN 180 NM
EITHER SIDE OF A LINE FROM 06N81W TO 09N100W TO 07N120W.
ISOLATED STRONG CONVECTION EXISTS FROM 06N TO 08N BETWEEN 82W
AND 86W. 

...DISCUSSION...

A 1023 MB HIGH IS CENTERED BETWEEN CALIFORNIA AND HAWAII NEAR
32N139W. A TROUGH OF LOW PRESSURE REACHES NORTHWESTWARD FROM
ARIZONA ALONG THE CALIFORNIA COAST. THIS TROUGH HAS BEGUN TO
FILL. LATEST ASCAT IMAGERY INDICATES STRONG NW WINDS FROM 30N TO
34N W OF THE CALIFORNIA COAST HAVE DECREASED TO FRESH IN
RESPONSE TO THE WEAKENING PRESSURE GRADIENT. WINDS OVER THE
NORTHERN GULF OF CALIFORNIA HAVE ALREADY DIMINISHED TO BELOW 20
KT AS WELL. SEAS W OF THE CALIFORNIA AND BAJA COASTS ARE
EXPECTED TO SUBSIDE TO BELOW 8 FT BY AROUND SUNRISE ON MON
MORNING.

A COLD FRONT WILL ENTER THE FAR NW CORNER OF THE AREA AROUND
NOON ON MON...THEN BEGIN TO WEAKEN. NW SWELL OF 8 TO 10 FT
GENERATED TO THE LEE OF THE FRONT WILL PROPAGATE TOWARD THE
CALIFORNIA AND BAJA COASTS ON TUE AND WED BUT DECAY ON THU.

THE PRES GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND LOWER
PRESSURE IN THE VICINITY OF THE ITCZ HAS DECREASED AS A COLD
FRONT MOVING EASTWARD FROM N OF HAWAII WEAKENS THE RIDGE. LATEST
ASCAT IMAGERY SHOWS THE AREA OF FRESH WINDS FROM 05N TO 20N W OF
120W CONTINUES TO SHRINK. THIS HAS ALLOWED TRADE-WIND WAVES AND
SWELL IN THIS AREA TO SUBSIDE. AS HIGH PRESSURE TO THE N
REBUILDS...WINDS WILL INCREASE BUT SEAS GREATER THAN 8 FT ARE
NOT EXPECTED.

LONG TERM MODEL GUIDANCE SUGGESTS A LATE SEASON COLD FRONT
ENTERING THE GULF OF MEXICO WILL TRIGGER A NEAR GALE FORCE
TEHUANTEPEC SURGE ON THURSDAY. 

$$
MCELROY