000
AXPZ20 KNHC 140237
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

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

THE MONSOON TROUGH EXTENDS FROM 08N84W TO LOW PRES EMBEDDED IN 
THE MONSOON TROUGH NEAR 07N95W 1007 MB TO 10N110W TO 09N119W 
WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS 
TO 08N128W TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 60 NM N AND 90 NM S OF AXIS BETWEEN 
86W AND 92W. NUMEROUS MODERATE ISOLATED STRONG CONVECTION WAS 
NOTED FROM 04N TO 12N BETWEEN 92W AND 100W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 90 NM N OF AXIS 
BETWEEN 100W AND 108W. SCATTERED MODERATE CONVECTION WAS 
NOTED WITHIN 60 NM OF AXIS BETWEEN 120W AND 130W. 

...DISCUSSION... 

LOW PRESSURE NEAR 07N95W IS EMBEDDED WITHIN THE MONSOON TROUGH. 
THE LOW HAS STRENGTHENED OVER THE PAST 24 HOURS WITH THE HELP OF 
SHEAR VORTICITY ASSOCIATED WITH GAP WINDS FROM THE GULFS OF 
TEHUANTEPEC AND PAPAGAYO. THOUGH CONVECTION HAS DECREASED 
SOMEWHAT OVER THE PAST FEW HOURS...ACTIVE CONVECTION STILL 
REMAINS ON THE SOUTH AND EAST PART OF THE LOW. THE LOW IS WITHIN 
A BAROTROPICALLY UNSTABLE ENVIRONMENT WHICH IS FAVORABLE FOR THE 
CONTINUED GROWTH OF THIS FEATURE...AND THE BREAKDOWN OF THE 
MONSOON TROUGH...WHICH MODEL GUIDANCE IS DEPICTING BY THE MIDDLE 
OF THE WEEK. THE BREAKDOWN OF THE MONSOON TROUGH ASSOCIATED WITH 
A WESTWARD PROPAGATING DISTURBANCE...IN THIS CASE A CARIBBEAN 
WAVE THAT PROPAGATED INTO THE EASTERN NORTH PACIFIC...HAS BEEN 
ASSOCIATED WITH TROPICAL CYCLOGENESIS IN SOME CASES. IT WILL BE 
INTERESTING TO WATCH THIS FEATURE OVER THE NEXT FEW DAYS. 

ELSEWHERE...HIGH PRESSURE 1031 MB IS CENTERED NNW OF THE AREA 
NEAR 34N141W WITH ASSOCIATED RIDGE EXTENDING SE TO NEAR 20N114W. 
THE PRESSURE GRADIENT BETWEEN THE AREA OF HIGH PRESSURE AND 
LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING 
MODERATE TO LOCALLY FRESH TRADES N OF THE ITCZ TO NEAR 20N AND W 
OF 125W AS DEPICTED BY THE LATEST SCATTEROMETER PASSES. THE AREA 
OF FRESH WINDS IS RESULTING IN SEAS TO 8 FT...MAINLY FROM 10N TO 
15N W OF 135W. THE HIGH PRESSURE CENTER WILL SHIFT NE OVER THE 
NEXT 24 HOURS. THIS WILL LOOSEN THE PRESSURE GRADIENT TO 
SLIGHTLY WEAKEN THE TRADES ENOUGH WHERE SEAS WILL SUBSIDE BELOW 
8 FT ON TUESDAY. 

$$
AL