000
AXPZ20 KNHC 021605
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 2 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 
1545 UTC.

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

THE MONSOON TROUGH EXTENDS FROM 08N82W TO 06N90W TO 06N96W WHERE 
LOW LEVEL WINDS SUGGEST THAT IT TRANSITIONS TO THE ITCZ TO 
07N111W TO 06N119W TO 06N129W TO 03N140W. SCATTERED MODERATE TO 
STRONG CONVECTION EXISTS FROM 02N TO 07N BETWEEN 98W AND 
102W...WITHIN 120 NM EITHER SIDE OF THE ITCZ BETWEEN 117W AND 
120W...AND WITHIN 120 NM N OF THE ITCZ W OF 129W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS SEEN FROM 04N TO 10N E OF 
90W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM THE FAR SWRN U.S. SW TO ACROSS
NRN BAJA AND TO A CUT-OFF LOW MOVING NE LOCATED NEAR 23N117.5W.
IT CONTINUES SW TO NEAR 14N124W. A JET STREAM BRANCH ENTERS THE 
WRN PORTION OF THE REGION THROUGH 17N140W...AND DIVES ESE TO 
ROUND THE BASE OF THE TROUGH...THEN STRETCHES NEWD TO ACROSS
CENTRAL BAJA CALIFORNIA AND NRN MEXICO. SATELLITE-DERIVED WIND
DATA INDICATES MAXIMUM WIND SPEEDS OF 70-90 KT ASSOCIATED WITH
THE JET. SATELLITE IMAGERY IS ALSO SHOWING MAINLY BROKEN HIGH
LEVEL CLOUDS STREAMING NEWD SE OF THE CUT-OFF LOW TO NEAR 19N.
OVER THE REMINDER OF THE AREA BEHIND THE TROUGH...AN UPPER LEVEL 
RIDGE NOSES SEWD FROM NEAR 28N140W TO 20N129W. THE ASSOCIATED 
UPPER LEVEL ANTICYCLONIC IS WELL W OF THE AREA...AND MOVING 
FURTHER AWAY.

S OF THE TROUGH AND IN THE TROPICAL PORTION OF THE AREA...AN 
UPPER LEVEL ANTICYCLONIC CIRCULATION IS NEAR 06N118W WITH AN E 
TO W RIDGE EXTENDING E TO NEAR 100W AND TO W OF THE AREA TO 
142W. IT IS BEING SUSTAINED BY ITCZ CONVECTION AS DESCRIBED 
ABOVE.

IN THE FAR E PORTION OF THE AREA...A MID TO UPPER LEVEL TROUGH 
EXTENDS FROM SE MEXICO AND THE GULF OF TEHUANTEPEC REGION SW TO 
TO NEAR 08N100W AND S TO 02N100W. IT IS HELPING TO ACTIVATE 
CONVECTION ALONG AND EITHER SIDE OF THE MONSOON TROUGH AS NOTED 
ABOVE. ATMOSPHERIC MOISTURE IS CONFINED TO THE DEEP TROPICS S OF 
11N...WHILE GENERALLY MODERATE SUBSIDENCE ALOFT PREVAILS 
MAINTAINING RATHER DRY AND STABLE CONDITIONS OVER THE REMAINDER OF 
THE DISCUSSION AREA.
 
AT THE SURFACE...THE SURFACE REFLECTION OF THE UPPER LEVEL RIDGE
EXTENDS THROUGH 32N137W SE TO 25N128W AND TO NEAR 20N123W. HIGH
PRES COVER THE AREA N OF 18N W OF 123W. THIS RIDGE IS FORECAST TO
BE REPLACED BY STRONGER HIGH PRES OVER THE NEXT 48 HOURS. A 
WEAKENING FRONTAL TROUGH OVER THE ERN PART OF THE AREA EXTENDS 
FROM NEAR NRN BAJA CALIFORNIA SSE TO 27N118W TO 23N125W. IT IS 
EXPECTED TO BECOME DIFFUSE AS IT MOVES EWD THROUGH TONIGHT. 

THE PRESENT PRES GRADIENT IS ANALYZED AS RATHER WEAK ACROSS MOST
OF THE ENTIRE REGION...WITH THE EXCEPTION OF THE FAR WRN PORTION 
WHERE SPORADIC NE TO E WINDS OF 20 KT WHERE SUGGESTED BY 
COMPOSITE SCATTEROMETER DATA FROM OVERNIGHT LAST NIGHT OVER
THE AREA FROM ABOUT 08N TO 22N W OF 130W. THIS AREA OF TRADE
WINDS IS FORECAST TO EXPAND SOME THROUGH THE NEXT 48 HRS AS
THE RIDGE STRENGTHENS. BY 48 HRS...NLY WINDS OF 20 KT ARE 
EXPECTED TO INFILTRATE THE FAR NRN WATERS N OF 28N...AND 
POSSIBLY TO ALONG THE FAR NRN BAJA CALIFORNIA COAST.

A SMALL AREA OF SW SWELL RESULTING IN 6-8 FT SEAS IS EXPECTED
TO CONTINUE INTO THU NIGHT ALONG THE EQUATOR BETWEEN 110W AND 
120W FROM THE SOUTHERN HEMISPHERE THROUGH THU NIGHT.

$$
AGUIRRE