000
AXPZ20 KNHC 180309
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI MAY 18 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 
0300 UTC.

...SPECIAL FEATURES...
TROPICAL DEPRESSION ALETTA IS CENTERED NEAR 13.6N 114.3W MOVING 
NNE OR 020 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRES 1006 MB. 
MAXIMUM SUSTAINED WINDS 30 KT GUSTS TO 40 KT. PLEASE REFER TO 
THE LATEST PUBLIC ADVISORY TCPEP1/WTPZ31 KNHC FOR MORE DETAILS. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 NM OF THE 
CENTER. ALETTA WILL SLOWLY WEAKEN DURING THE NEXT 48 HOURS AS 
THE SURROUNDING ENVIRONMENT BECOMES UNFAVORABLE FOR DEVELOPMENT.

A BROAD AREA OF LOW PRES IS EMBEDDED WITHIN THE MONSOON TROUGH 
AND CENTERED NEAR 13N101W. CONVECTIVE ACTIVITY ASSOCIATED WITH 
THE DISTURBANCE REMAINS POORLY ORGANIZED. SATELLITE IMAGERY 
SHOWS SCATTERED MODERATE TO STRONG CONVECTION WITHIN 60 TO 75 NM 
OF THE POORLY DEFINED LOW LEVEL CENTER. GLOBAL MODEL FORECASTS 
ARE IN FAIRLY GOOD AGREEMENT. THIS SYSTEM IS LIKELY TO INTENSIFY 
OVER THE NEXT FEW DAYS IN AN ENVIRONMENT OF FAVORABLE UPPER 
LEVEL DIFFLUENCE. THERE IS A MEDIUM CHANCE OF BECOMING A 
TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES VERY 
SLOWLY TO THE NW.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
AN ACTIVE MONSOON TROUGH EXTENDS FROM 08N78W TO 08N88W TO 14N97W 
TO A LOW PRES NEAR 12N101W 1008 MB TO 14N111W. THE ITCZ EXTENDS 
FROM 06N119W TO 05N127W TO 08N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS FROM 05N TO 14N E OF 102W.

...DISCUSSION...
AN ACTIVE MONSOON TROUGH E OF 115W IS ANCHORED BY TD ALETTA NEAR 
13.6N114.3W AND A BROAD LOW PRES AREA CENTERED NEAR 13N101W. AN 
UPPER LEVEL ANTICYCLONE CENTERED NEAR 12N95W IS ENHANCING DEEP 
CONVECTION E OF 116W. THE SUBTROPICAL RIDGE AT THE SURFACE HAS 
WEAKENED OVER THE PAST 24 HOURS. GENTLE TO MODERATE WINDS ARE 
EVIDENT FROM SCATTEROMETER DATA ACROSS THE ENTIRE REGION... 
EXCEPT IN THE GULF OF TEHUANTEPEC. 

EXPECT THE MONSOON TROUGH TO REMAIN THE DOMINANT SYNOPTIC FEATURE
THE NEXT 1-2 DAYS WHILE WEAKER THAN NORMAL TRADE WINDS CONTINUE 
W OF 120W. THE REMNANT LOW OF ALETTA IS FORECAST TO BE ABSORBED 
INTO THE LARGER CYCLONIC CIRCULATION NEAR 13N100W AS IT WEAKENS. 
FRESH TO STRONG N-NW WINDS N OF THE AREA ALONG THE CALIFORNIA 
COAST WILL GENERATE NLY SWELL THAT WILL PUSH S OF 30N THROUGH 
SAT.

$$
MUNDELL