000
AXPZ20 KNHC 282115
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT APR 28 2012

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 08N83W TO 03N102W. THE ITCZ 
EXTENDS FROM 03N102W TO 06N116W TO 01N140W. ISOLATED MODERATE TO 
STRONG CONVECTION WAS NOTED WITHIN 120 NM OF AXIS BETWEEN 87W 
AND 96W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED 
WITHIN 120 NM N OF AXIS BETWEEN 114W AND 126W.

...DISCUSSION...
STRONG 1036 MB HIGH PRES IS CENTERED NEAR 34N142W WITH RIDGE 
EXTENDING SE TO NEAR 16N109W. THE PRESSURE GRADIENT BETWEEN THIS 
FEATURE AND TROUGHING OVER THE SW UNITED STATES AND MEXICO IS 
MAINTAINING FRESH NW WINDS IN A BROAD AREA N OF 25N BETWEEN 120W 
AND 130W AS DEPICTED BY THE LATEST ASCAT PASS. THE PRESSURE 
GRADIENT BETWEEN THE AREA OF HIGH PRES AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ IS ALSO MAINTAINING FRESH TRADE WINDS FROM 
05N TO 20N W OF 120W AS DEPICTED BY THE LATEST ASCAT PASS. THE 
AREA OF HIGH PRESSURE WILL SLOWLY SHIFT W-NW AND SLIGHTLY WEAKEN 
OVER THE NEXT TWO DAYS...WHICH WILL ALLOW THE REGION OF HIGHEST 
TRADES AND WIND-DRIVEN SEAS TO GRADUALLY SHIFT W OF 132W BY MON. 

GALE FORCE WINDS N OF THE AREA ALONG THE CALIFORNIA COAST HAS 
SPREAD NW SWELL INTO THE N PART OF THE AREA...WITH COMBINED SEAS 
NEAR 13 FT N OF 25N BETWEEN 118W AND 128W. THIS SWELL EVENT WILL 
PROPAGATE SOUTHWARD WHILE SLOWLY SUBSIDING DURING THE REST OF 
THE WEEKEND. 

E OF 110W...GENTLE TO MODERATE BREEZE AND SEAS BELOW 8 FT ARE 
NOTED WITH CROSS EQUATORIAL SW SWELL WITH PERIODS IN THE 13-15 
SECOND RANGE. THIS WEATHER PATTERN IS FORECAST TO PERSIST DURING 
THE NEXT COUPLE OF DAYS.

$$
AL