000 AXPZ20 KNHC 302156 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE APR 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 06N77W ACROSS THE PACIFIC COASTS OF PANAMA AND COSTA RICA TO 10N88W...THEN DIPS SW TO 07N112W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ AXIS CONTINUES WESTWARD ALONG 07N TO AN EMBEDDED 1009 MB LOW PRES AT 08.5N136W...WITH THE ITCZ THEN CONTINUING W BEYOND 07N140W. ISOLATED MODERATE AND STRONG CONVECTION IS OBSERVED WITHIN 120 NM OF 05N85W AND FROM 04N TO 14N BETWEEN 90W AND 101W... AND WITHIN 15 NM OF THE ITCZ AXIS BETWEEN 129W AND 137W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 150 NM EITHER SIDE OF A LINE FROM 05N109W TO 09N112W TO 10N116W...AND ALSO WITHIN 90 NM OF 12.5N126W. THE LOW PRESSURE SYSTEM AT 08.5N136W IS EXPECTED TO MOVE W AND DISSIPATE OVER THE NEXT 24 HOURS. ...DISCUSSION... GULF OF CALIFORNIA...S TO SW WINDS ARE AT 5 TO 10 KT ACROSS THE ENTIRE THE GULF OF CALIFORNIA WITH SEAS 1 TO 2 FT EXCEPT 3 FT OVER THE SOUTHERN GULF WATERS DUE TO LONG PERIOD SOUTHERLY SWELL. THE SOUTHERLY FLOW WILL INCREASE TO 10 TO 15 KT TONIGHT INTO EARLY WED THEN DIMINISH TO 5 TO 10 KT BY MIDDAY WED. THE LIGHT LOW LEVEL FLOW WILL BECOME NW ON WED NIGHT. THE NW WINDS WILL INCREASE TO 10 TO 15 KT ON THU MORNING AND THEN QUICKLY INCREASE TO 15 TO 20 KT ACROSS THE ENTIRE GULF THU AFTERNOON...AND FURTHER INCREASE TO 20 TO 25 KT ON THU EVENING AS SEAS BUILD TO 5 TO 8 FT ACROSS THE WATERS N OF 26N. THE NW WINDS WILL DIMINISH LATE THU NIGHT INTO FRI WITH LIGHT AND VARIABLE WINDS AND SEAS 2 FT OR LESS ON SAT. GULF OF TEHUANTEPEC...S TO SW WINDS AT 5 TO 15 KT ARE EXPECTED ACROSS THE GULF OF TEHUANTEPEC THROUGH THU EVENING. NORTHERLY WINDS WILL SURGE THROUGH THE CHEVILA PASS LATE THU NIGHT...INITIALLY AT 10 TO 15 KT...BUT QUICKLY INCREASE 20 TO 25 KT FRI AFTERNOON WITH SEAS BUILDING TO 10 FT. THE N FLOW WILL INCREASE TO 20 TO 30 KT FRI NIGHT WITH A SMALL AREA OF MINIMAL GALE FORCE WINDS EXPECTED LATE FRI NIGHT THROUGH SUNRISE ON SAT...WITH SEAS BUILDING TO 13 FT NEAR 14.5N95W AT SUNRISE SAT. THE WINDS WILL DIMINISH SAT MORNING WITH SEAS OF 8 TO 10 FT REACHING AS FAR S AS 10.5N96.5W. GULF OF PAPAGAYO...LIGHT AND VARIABLE WINDS AND LONG PERIOD SW SWELL...WITH SEAS 3 TO 5 FT...ARE EXPECTED THROUGH SAT EVENING...THEN ENE FLOW AT 10 TO 15 KT IS EXPECTED LATE SAT NIGHT INTO SUN MORNING. GULF OF PANAMA...LIGHT AND VARIABLE WINDS AT 5 TO 10 KT ARE EXPECTED THROUGH SUN. SURFACE HIGH PRESSURE IS ANALYZED NW OF THE AREA WITH A RIDGE AXIS EXTENDING SE INTO THE DISCUSSION AREA FROM 32N134W TO 18N108W. THE GRADIENT IS SUPPORTING N WINDS AT 15 TO 20 KT ACROSS THE PACIFIC WATERS N OF 28N BETWEEN 122W AND 132W WITH SEAS 7 TO 10 FT IN MIXING N AND S SWELL. THE AFFECTED AREA WILL EXPAND S TO ALONG 27N BETWEEN 118W AND 134W ON WED... THEN BEGIN TO SHRINK TO LESS THAN 20 KT ON THU. A SMALL AREA OF ENHANCED WINDS AT 15 TO 20 KT IS NOTED SW OF THE RIDGE IN THE AREA FROM 10N TO 14N BETWEEN 130W AND 135W...WITH SEAS 6 TO 8 FT IN MIXED NE AND S SWELL. THESE NE TRADES WILL DIMINISH BELOW 20 KT ON THU. THE RIDGE WILL SHIFT LATE IN THE WEEK ALLOWING A WEAK COLD FRONT TO SWEEP E ACROSS THE PACIFIC WATERS N OF 27N BETWEEN 120W AND 130W...ACCOMPANIED BY ONLY A 15 TO 20 KT SW TO W TO NW WIND SHIFT. $$ NELSON