000
AXPZ20 KNHC 172148
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU MAY 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURES...
TROPICAL DEPRESSION ALETTA IS CENTERED NEAR 13.1N 114.7W MOVING 
N OR 360 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 MAINLY E OF THE 
LOW LEVEL CENTER FROM 10N TO 15N BETWEEN 94W AND 100W. GLOBAL 
MODEL FORECASTS ARE IN FAIRLY GOOD AGREEMENT THAT THIS SYSTEM IS 
LIKELY TO INTENSIFY OVER THE NEXT SEVERAL 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 06N77W TO A LOW PRES NEAR 
13N101W 1008 MB TO 13N110W. THE ITCZ EXTENDS FROM 05N120W TO 
06N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 30 NM 
N TO 75 NM S OF THE TROUGH AXIS E OF 100W.

...DISCUSSION...
AN ACTIVE MONSOON TROUGH E OF 115W IS ANCHORED BY TD ALETTA NEAR 
13N115W 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 HAS WEAKENED OVER 
THE PAST 24 HOURS...AND GENTLE TO MODERATE WINDS ARE EVIDENT 
FROM SCATTEROMETER DATA ACROSS THE ENTIRE REGION...EXCEPT NEAR 
TD ALETTA AND 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. FRESH TO STRONG N-NW WINDS N OF THE AREA ALONG THE 
COAST OF CALIFORNIA WILL GENERATE NLY SWELL THAT WILL PUSH S OF 
30N THROUGH SAT.

$$
MUNDELL