000
AXPZ20 KNHC 071554
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT APR 07 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

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

ITCZ FROM 04N106W TO 02N127W TO 02N136W.  NO SIGNIFICANT 
CONVECTION.

DISCUSSION...
WEAKENING 1022 MB HIGH PRES AT 31N127W WITH RIDGE EXTENDING TO 
16N102W...BOTH BEING FORCED SE BY INCOMING HEALTHY COLD FRONT 
PRESENTLY EXTENDING FROM 32N135W TO 28N140W.  FRESH SWLY BREEZE 
WITHIN 120 NM AHEAD OF FRONT DIMINISH TO A MODERATE BREEZE 
TONIGHT WHILE STRONG WINDS W OF BOUNDARY REMAIN N OF 32N.   AIR 
MASS UNDER RIDGE IS KEPT DRY AND STABLE UNDER MODERATE TO STRONG 
SUBSIDENCE ALMOST THROUGHOUT ENTIRE BASIN EXCEPT UPPER LEVEL 
MOISTURE ADVECTED BY RIDGE FROM 20N TO 25N W OF 125W AND THAT  
ASSOCIATED WITH COLD FRONT.

AT THE LOWER LEVELS...
SURFACE TROUGH FROM 07N86W TO 00N92W ABLE TO UPLIFT SOME 
MOISTURE COMING OUT OF SOUTH AMERICA ENHANCED BY MODERATE UPPER 
LEVEL DIVERGENT FLOW.  OTHERWISE...EVEN ITCZ REMAINS DEVOID OF 
SIGNIFICANT CONVECTION.  

LARGE AREA OF NW SWELL LINGER FROM PREVIOUS COLD FRONT AND 
EXTEND S TO 10N W OF 115W.  SWELL HARDLY DIMINISH BELOW 8 FT 
WHEN SECOND TRAIN OF SWELL...AS HIGH AS 14 FT...THIS ONE FROM 
COLD FRONT MENTIONED ABOVE ENTERS NW CORNER OF BASIN AND SPREAD 
S TO 20N W OF 125W. 

SIMILARLY...CROSS EQUATORIAL 9 FT SWELL AFFECTING WATERS S OF 
10N W OF 95W SUBSIDING IN SIZE AND COVERAGE BY EARLY MON. 

$$
WALLY BARNES