000
AXPZ20 KNHC 251002
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC THU APR 25 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 
0715 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
 
THE MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 05N77W TO 
06N83W TO 07N89W...WHERE IT TRANSITIONS TO ITCZ AT 07N95W TO 
08N107W THEN CONTINUES FROM 08N111W TO 05N140W. A SURFACE TROUGH 
EXTENDS FROM 13N107W TO 08N109W. SCATTERED MODERATE TO STRONG 
CONVECTION IS FROM 05N TO 15N BETWEEN 104W AND 109W. SCATTERED 
MODERATE CONVECTION IS WITHIN 240 NM S OF THE ITCZ BETWEEN 100W 
AND 104W. 
       
...DISCUSSION... 

STRONG TO NEAR GALE FORCE WINDS ARE EXPECTED TO DEVELOP IN THE 
GULF OF TEHUANTEPEC THURSDAY NIGHT EXTENDING TO FRIDAY WITH SEAS 
BUILDING UP TO 11 FEET DUE TO HIGH PRESSURE BUILDING IN THE 
WESTERN GULF OF MEXICO. 

CONVECTION NEAR THE SURFACE TROUGH FROM 13N107W TO 08N109W AND 
THE COINCIDENT ITCZ IS DESCRIBED ABOVE. UPPER LEVEL DIVERGENCE 
JUST SOUTH OF THE ITCZ IS ENHANCING THE STRONGER CONVECTION 
FOUND NEAR THE ITCZ AXIS. THIS SURFACE TROUGH IS EXPECTED TO 
REMAIN BETWEEN 110W AND 120W DURING THE NEXT 48 HOURS. 
SHOWERS/THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE 
TROUGH AS UPPER LEVEL DIVERGENCE CONTINUES THROUGH THIS PERIOD.

A 1031 MB SURFACE HIGH LOCATED NEAR 46N136W EXTENDS A RIDGE SW 
TO 25N150W AND THEN TAKES A SHARP TURN INTO THE FORECAST AREA TO 
25N114W. A SURFACE LOW WITH A MAGNITUDE OF 1012 MB IS LOCATED 
NEAR 31N121W AND EXTENDS A SURFACE TROUGH INTO THE FORECAST AREA 
ALONG 30N121W 24N124W 22N130W WITH NO CONVECTION ASSOCIATED TO 
IT. THE INTERFERENCE FROM THIS LOW IS WEAKENING THE SUBTROPICAL 
RIDGE...RESULTING IN TRADEWINDS LESS THAN 20 KT OVER THE 
FORECAST AREA. WITHIN THE NEXT 24 HOURS...THIS LOW IS EXPECTED 
TO DISSIPATE...BUT A NEW TROUGH WILL DEVELOP FARTHER W AND 
CONTINUE TO COMPROMISE THE SUBTROPICAL RIDGE AND KEEP TRADE 
WINDS BELOW A STRONG BREEZE. 
 

$$
NR/JS