000 AXPZ20 KNHC 012156 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED MAY 01 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 W FROM THE COAST OF COLOMBIA AT 07N78W ACROSS THE FAR SOUTHERN COAST OF PANAMA TO 10N93W... THEN DIPS SW TO 07N100W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ AXIS CONTINUES SW TO 03N111W THEN W TO 03N125W...THEN TRACKS NW THROUGH 06N133W BEFORE TURNING SW TO BEYOND 04N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED MAINLY S OF THE EASTERN SEGMENT OF THE MONSOON TROUGH AXIS ROUGHLY WITHIN 120 NM EITHER SIDE OF A LINE FROM 05N77W TO 10N98W...WITH THE CONVECTION CURRENTLY DECREASING IN INTENSITY. ISOLATED CLUSTERS OF MODERATE CONVECTION IS NOTED NEAR THE ITCZ WITHIN 60 NM EITHER SIDE OF A LINE FROM 08N127W TO 05N134W. LOCALLY OVERCAST MULTI-LAYERED CLOUDS...WITH SCATTERED MODERATE CONVECTION OCCASIONALLY FLARING UNDER THESE CLOUDS...IS ENHANCED ALONG THE W PERIPHERY OF AN UPPER RIDGE IN THE AREA JUST N OF THE ITCZ FROM 11N TO 17N BETWEEN 119W AND 127W. THE RESULTANT UPPER DEBRIS MOISTURE CONCENTRATES INTO A 180 NM WIDE MOISTURE PLUME THAT STREAMS E ACROSS MEXICO AND THE BAY OF CAMPECHE ALONG 20N. ...DISCUSSION... GULF OF CALIFORNIA...S TO SW WINDS ARE AT 5 TO 10 KT ACROSS THE ENTIRE THE GULF OF CALIFORNIA WITH SEAS OF 1 TO 2 FT... EXCEPT 2 TO 4 FT OVER THE SOUTHERN GULF OF CALIFORNIA WATERS PRIMARILY DUE TO LONG PERIOD SOUTHERLY SWELL. THIS LIGHT SOUTHERLY FLOW WILL BECOME NORTHERLY EARLY TONIGHT THEN INCREASE 20 TO 25 KT OVER THE WATERS N OF 30N...WHILE MOSTLY 10 TO 15 KT ACROSS THE WATERS S OF 30N BY LATE TONIGHT. THESE STRONG NW WINDS WILL QUICKLY SPREAD S ACROSS ALL WATERS N OF 26N ON THU AFTERNOON WITH SEAS BUILDING 5 TO 8 FT IN THE LONG NW TO SE FETCH NEAR 30N. THE GRADIENT WILL RELAX ON THU NIGHT INTO FRI WITH THE N FLOW DIMINISHING TO LIGHT AND VARIABLE WINDS...AND SEAS 2 FT OR LESS ON FRI NIGHT. THE LOW LEVEL FLOW WILL BECOME SOUTHERLY AGAIN ON SAT INCREASING TO 10 TO 15 KT. A SURFACE LOW PRESSURE CENTER IS EXPECTED OVER THE FAR NORTHERN WATERS ON SUN NIGHT ACCOMPANIED BY 15 TO 20 KT WINDS. GULF OF TEHUANTEPEC...S TO SW WINDS AT 5 TO 10 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 30 KT BY LATE FRI AFTERNOON AS SEAS BUILD TO 10 FT. THE N FLOW WILL INCREASE TO MINIMAL GALE FORCE FRI NIGHT TILL JUST AFTER SUNRISE ON SAT...WITH SEAS BUILDING TO 13 FT NEAR 14.5N95W AT SUNRISE SAT. THE WINDS WILL DIMINISH LATE SAT MORNING WITH SEAS OF 8 FT REACHING AS FAR S AS 10N96W ON SAT EVENING. AS THE NE SWELL PROPAGATES SW AND GRADUALLY SUBSIDES TO 6 FT ON SUN AND 5 FT SUN NIGHT... WINDS WILL BECOME LIGHT AND VARIABLE ACROSS THE GULF OF TEHUANTEPEC WITH LITTLE CHANGE THROUGH MON. GULF OF PAPAGAYO...LIGHT AND VARIABLE WINDS AND LONG PERIOD SW SWELL...WITH SEAS 3 TO 5 FT...ARE EXPECTED THROUGH SAT EVENING...THEN E-NE FLOW AT 10 TO 15 KT IS FORECAST BRIEFLY FROM LATE SAT NIGHT INTO SUN MORNING AND AGAIN ON SUN NIGHT INTO MON 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 18N110W. THE GRADIENT IS SUPPORTING N WINDS AT 15 TO 20 KT ACROSS THE PACIFIC WATERS N OF 27N BETWEEN 120W AND 134W WITH SEAS 7 TO 9 FT PRIMARILY DUE TO N SWELL. THE AFFECTED AREA WILL GRADUALLY SHRINK ON THU WITH WINDS LESS THAN 20 KT AND SEAS LESS THAN 8 FT BY THU EVENING. THE RIDGE WILL SHIFT S LATE IN THE WEEK ALLOWING A WEAK COLD FRONT TO SWEEP E ACROSS THE PACIFIC WATERS N OF 27N E OF 115W ON FRI AND SAT...BUT ONLY ACCOMPANIED BY 5 TO 10 KT SW TO W TO NW WIND SHIFT. $$ NELSON