000
AXPZ20 KNHC 090241
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED MAY 09 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 ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0200 UTC.

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

MONSOON TROUGH ANALYZED FROM LOW PRES NEAR 08N87.5W 1009 MB TO 
08N96W TO 09N117W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON 
TO 03N133W TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NOTED S OF MONSOON TROUGH TO 03N BETWEEN 87W AND 
100W...AND WITHIN 120 NM N AND 240 NM S OF TROUGH BETWEEN 102W 
AND 116W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM 
N AND 60 NM S OF ITCZ AXIS W OF 117W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION FROM 08.5N TO 12N E OF 89W TO THE 
COASTS OF NICARAGUA AND COSTA RICA.

...DISCUSSION...

ALOFT...A RELATIVELY STAGNANT UPPER LEVEL PATTERN PREVAILS EARLY 
TONIGHT...WITH A TROUGH/RIDGE/TROUGH PATTERN SPANNING THE AREA E 
OF 150W. A MIDDLE/UPPER LEVEL CUT-OFF LOW IS JUST W OF THE 
FORECAST AREA NEAR 20N145W....WITH WELL DEFINED MID LEVEL CENTER 
BEGINNING TO DRIFT NE...AND UPPER TROUGH EXTENDING SE TO NEAR 
07N133W. A MIDDLE/UPPER LEVEL TROUGH EXTENDS FROM A CUT-OFF LOW 
CENTERED OVER THE EXTREME NW MEXICO-SW ARIZONA BORDER NEAR 
32N113.5W WITH TROUGH TO NEAR 21N119W. STRONG SUBSIDENCE NOTED 
IN WATER VAPOR IMAGERY IN BASE OF TROUGH SUGGESTING STRONG 
CONVERGENCE ALOFT. IN BETWEEN...THERE IS A RIDGE COVERING THE NW 
PORTION OF THE FORECAST AREA. OTHERWISE...MAINLY BROAD 
ANTICYCLONIC FLOW DOMINATES THE REMAINDER OF THE DISCUSSION 
WATERS. PERSISTENT AND ACTIVE CONVECTION ALONG AND NEAR THE ITCZ 
AND MONSOON TROUGH E OF 125W IS AIDING IN MAINTAINING THIS 
RIDGING ALOFT. 

AT THE LOWER LEVELS...A COLLAPSING 1029 MB HIGH PRES WAS LOCATED 
NW OF THE DISCUSSION AREA NEAR 33N141W AND EXTENDS A RIDGE TO 
THE SE TO NEAR THE REVILLAGIGEDO ISLANDS NEAR 19N112W. THE PRES 
GRADIENT  BETWEEN THIS RIDGING AND LOWER PRES ALONG CALIFORNIA 
AND THE NORTHERN BAJA CALIFORNIA PENINSULA IS RESULTING IN AN 
AREA OF FRESH NORTHERLY WINDS N OF 27N BETWEEN 126W AND 133W. 
THIS WEATHER PATTERN AND CONDITIONS WILL PERSIST THROUGH AT 
LEAST THU AS STRONGER HIGH PRES SETTLES N OF AREA...AND A WEAK 
COLD FRONTAL BOUNDARY SINKS ACROSS NW PORTIONS TO ALONG 29N. 
MEANWHILE FRESH NE TRADES OCCURRING ON THE SOUTHERN PERIPHERY OF 
THE RIDGE HAVE DIMINISHED TO LESS THAN 20 KT...WITH A FEW VERY 
SMALL AREAS TO 20 KT POSSIBLE...ESPECIALLY S OF 11N WHERE INFLOW 
TO ACTIVE ITCZ CONVECTION IS ENHANCING PREVAILING WINDS. 
TRADEWINDS ACROSS THIS AREA WILL REMAIN BELOW 20 KT FOR THE 
NEXT FEW DAYS.

THE REMAINDER OF THE DISCUSSION AREA WATERS ARE UNDER THE 
INFLUENCE OF MAINLY GENTLE TO MODERATE BREEZE N OF THE MONSOON 
TROUGH AND LIGHT TO MODERATE MONSOONAL FLOW TO THE S. SEAS E OF 
120W ARE GENERALLY 6 FT OR LESS...AND ARE BEGIN DOMINATED BY 
PULSES OF SMALL SOUTHERN HEMI LONG PERIOD SWELL. EXCEPT FOR 
ACTIVE CONVECTION CONTINUING S OF THE MONSOON TROUGH...THESE 
MOSTLY FAIR WEATHER CONDITIONS ARE EXPECTED TO PERSIST THROUGH 
THE REST OF THE WORK WEEK.

$$
STRIPLING