000
AXPZ20 KNHC 312147
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 31 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2130 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N77W TO 
04N100W TO 07N120W TO 05N140W. SCATTERED MODERATE TO STRONG 
WITHIN 60 NM EITHER SIDE OF AXIS FROM 81W TO 87W.

...DISCUSSION...

ALOFT...A MID TO UPPER-LEVEL TROUGH EXTENDS SW FROM NORTHERN 
BAJA CALIFORNIA PENINSULA TO NEAR 26N140W. THE SUBTROPICAL JET 
WITH CORE WINDS OF 90-110 KT IS JUST SOUTH OF THE TROUGH WHICH 
IS EXPECTED TO DRIFT E OVER THE NEXT 24 HOURS. A SHORT-WAVE 
TROUGH HAS ENTERED THE FORECAST AREA AND LIES ALONG 138W FROM 5N 
TO 13N. UPPER DIFFLUENCE AHEAD OF THIS TROUGH IS HELPING TO 
INDUCE ISOLATED SHOWERS FROM 8N-11N WEST OF 135W. A RIDGE 
CENTERED ON A HIGH NEAR 11N109W COVERS MUCH OF THE AREA E OF 
124W AND S OF 20N INCLUDING SE MEXICO AND N CENTRAL AMERICA.  
MODERATE TO STRONG UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR 
MASS IS NOTED WITHIN THE RIDGE AXIS PARTICULARLY ON THE EAST 
SIDE OF THE HIGH. THE RIDGE IS EXPECTED TO REMAIN NEARLY 
STATIONARY OVER THE NEXT 24 HOURS.  

AT THE SURFACE...A 1040 MB HIGH LOCATED NW OF THE DISCUSSION 
AREA NEAR 37N145W HAS A RIDGE EXTENDING SE INTO THE FORECAST 
REGION TO NEAR 16N110W. THIS FEATURE IS PRODUCING FRESH TO 
STRONG WINDS OF 20 TO 25 KT MAINLY FROM 15N TO 25N W OF 120W. AN 
EARLIER QSCAT PASS CONFIRMED THESE WIND SPEEDS. GALE FORCE WINDS 
ARE EXPECTED TO DEVELOP JUST N OF THE FORECAST AREA NEAR THE 
COAST OF CALIFORNIA DUE TO THE THIGH PRES GRADIENT BETWEEN THIS 
HIGH AND LOWER PRES OVER THE SW CONUS. THE HIGH IS EXPECTED TO 
REMAIN NW OF THE AREA OVER THE NEXT 24 HOURS AS THE RIDGE SLOWLY 
EXTENDS FURTHER SE INTO THE REGION. AN AREA OF MODERATE TO 
ISOLATED STRONG CONVECTION REMAINS WITHIN 60 NM EITHER SIDE OF 
ITCZ AXIS FROM 81W TO 87W. THE GLOBAL MODELS DO NOT INDICATE ANY 
SIGNIFICANT DEVELOPMENT IN THE NEAR TERM. 

$$
GR