000
AXPZ20 KNHC 140925
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC TUE MAY 14 2013

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
9000 UTC.

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

ACTIVE MONSOON TROUGH EXTENDS FROM 08N78W TO LOW PRES EMBEDDED 
IN TROUGH NEAR 07N96W 1008 MB TO 10N110W TO 09N124W...THEN ITCZ 
TO 07N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 
NM S OF THE AXIS E OF 85W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 90W AND 102W. 
SCATTERED MODERATE TO STRONG CONVECTION FROM 08N TO 14N BETWEEN 
99W AND 104W. 

...DISCUSSION...

ASCAT SCATTEROMETER PASS OVER THE GULF OF TEHUANTEPEC AT 0400 
UTC REVEALED SMALL AREA OF 35 KT GALE-FORCE WINDS NEAR 15.5N95W. 
FOR THIS REASON A GALE WARNING IS IN EFFECT...FOR THE GULF OF 
TEHUANTEPEC N OF 15N...THROUGH THE EARLY MORNING MAX UNTIL ABOUT 
1500 UTC. MODEL GUIDANCE INDICATES WINDS WILL BE BELOW GALE BY 
18Z. EXPECT 20-30 KT WINDS TO PERSIST THROUGH WED MORNING.

LOW PRES EMBEDDED IN AN ACTIVE EARLY SEASON MONSOON TROUGH NEAR 
07N96W HAS STRENGTHENED OVER THE PAST 24 HOURS...WITH THE HELP 
OF SHEAR VORTICITY ASSOCIATED WITH GAP WINDS FROM THE GULFS OF 
TEHUANTEPEC AND PAPAGAYO. CONVECTIVE ORGANIZATION HAS DECREASED 
SOMEWHAT OVER THE PAST 6-9 HOURS...BUT ACTIVE CONVECTION REMAINS 
SOUTH AND WEST OF THE LOW. THE LOW IS WITHIN A BAROTROPICALLY 
UNSTABLE ENVIRONMENT WHICH IS FAVORABLE FOR CONTINUED GROWTH OF 
THIS FEATURE...LEADING TO A BREAKDOWN OF THE MONSOON TROUGH... 
WHICH MODEL GUIDANCE IS DEPICTING BY WED. THE BREAKDOWN OF THE 
MONSOON TROUGH ASSOCIATED WITH A WEST-PROPAGATING DISTURBANCE... 
IN THIS CASE A CARIBBEAN WAVE THAT MOVED INTO THE EASTERN NORTH 
PACIFIC...HAS BEEN ASSOCIATED WITH TROPICAL CYCLOGENESIS IN SOME 
CASES. GLOBAL MODELS ARE BULLISH ON THIS DISTURBANCE BECOMING A 
TROPICAL CYCLONE SOMEWHERE BETWEEN 105W AND 110W WITHIN THE NEXT 
2-3 DAYS.

ELSEWHERE...HIGH PRES NNW OF THE AREA WITH SFC RIDGE EXTENDING 
SE TO NEAR 20N114W. THE GRADIENT BETWEEN THIS RIDGE AND LOWER 
PRESSURE NEAR THE ITCZ IS MAINTAINING MODERATE TO LOCALLY FRESH 
TRADES N OF THE ITCZ W OF 130W. THE HIGH WILL SHIFT NE OVER THE 
NEXT 24 HOURS AND DECREASE THE PRESSURE GRADIENT TO WEAKEN THE 
TRADES AND ALLOW SEAS TO SUBSIDE TO 6-7 FT THROUGH THU. 

$$
MUNDELL