000
AXPZ20 KNHC 130240
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC MON MAY 13 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 09N84W TO 09N100W WHERE LOW 
LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 
10N109W THEN TO BEYOND 08N140W. NUMEROUS MODERATE ISOLATED 
STRONG CONVECTION WAS NOTED FROM 05N TO 12N BETWEEN 90W AND 96W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM N AND 120 
NM S OF ITCZ AXIS BETWEEN 106W AND 117W. SCATTERED MODERATE 
CONVECTION WAS NOTED WITHIN 150 NM N OF AXIS W OF 125W.

...DISCUSSION... 

A 1028 MB HIGH PRESSURE CENTER IS LOCATED NEAR 32N128W WITH 
RIDGE EXTENDING SE TO NEAR 19N108W. THE PRESSURE GRADIENT 
BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO FRESH TRADES N 
OF THE ITCZ TO NEAR 20N AND W OF 120W AS DEPICTED BY THE LATEST 
SCATTEROMETER PASSES. THESE WINDS ARE PRODUCING ENOUGH 
CONVERGENCE INTO THE ITCZ TO PRODUCE ACTIVE CONVECTION ALONG THE 
ITCZ AS MENTIONED IN THE SECTION ABOVE. THE LARGE AREA OF FRESH 
WINDS IS RESULTING IN SEAS TO 8 FT FROM 08N TO 15N W OF 130W AS 
CONFIRMED BY RECENT ALTIMETER PASS.

A DISSIPATING STATIONARY FRONT IS IN THE FAR NW PART OF THE 
FORECAST AREA. UPPER SUPPORT FOR THIS FEATURE HAS LIFTED 
OUT...AND THE BOUNDARY WILL DISSIPATE OVER THE NEXT 24 HOURS. 
HIGH PRES BEHIND THE DYING FRONT WILL BUILD E AND MERGE WITH THE 
HIGH PRES NEAR 128W. THIS WILL MAINTAIN THE AREA OF MODERATE TO 
FRESH TRADES AND SEAS TO 8 FT MENTIONED ABOVE. 

LATEST SATELLITE OBSERVATIONS ALONG WITH SATELLITE HOVMOLLERS 
INDICATES THE CARIBBEAN WAVE/TROUGH IS IN THE EASTERN PACIFIC 
ROUGHLY ALONG 93W WITH ASSOCIATED SURFACE LOW PRESSURE NEAR 
08.5N93W EMBEDDED WITHIN THE MONSOON TROUGH. THE WAVE/TROUGH AND 
ASSOCIATED LOW ARE EXPECTED TO DRIFT WESTWARD ACROSS THE 
TROPICAL E PACIFIC THROUGH MID WEEK. IN ADDITION TO ENHANCED 
CONVECTION ASSOCIATED WITH THIS FEATURE...GAP WINDS THROUGH THE 
GULF OF PAPAGAYO WILL REACH 25 KT EACH MORNING WITH SEAS 
REACHING 8 FT WITHIN AND DOWNWIND OF THE GULF OF PAPAGAYO. THE 
COMBINATION OF THE WAVE/TROUGH SHIFTING WESTWARD AND A COLD 
FRONT IN THE GULF OF MEXICO REACHING THE BAY OF CAMPECHE WILL 
INDUCE GAP WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF 
TEHUANTEPEC OVERNIGHT. WINDS IN THE GULF OF TEHUANTEPEC WILL 
REACH 25 KT DURING THE OVERNIGHT HOURS...AND 30 KT BY MON 
MORNING. 
 
$$
AL