000 AXPZ20 KNHC 262147 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE MAR 26 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 06N77W TO 06N84W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ THEN EXTENDS SW TO 03N98W WHERE IT IS BRIEFLY DISRUPTED. THE ITCZ REDEVELOPS AT 04N112W AND WIGGLES W THROUGH 02N123W TO BEYOND 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED IN CLUSTERS ALONG THE MONSOON TROUGH AND ITCZ WITHIN 120 NM OF 05N79W...07N85W... 05N93W...05N108W AND 02N133W. ...DISCUSSION... GULF OF TEHUANTEPEC...A N TO S ORIENTATED SURFACE RIDGE EXTENDS FROM S TEXAS TO THE WESTERN BAY OF CAMPECHE WITH N WINDS SURGING THROUGH THE CHIVELA PASS INTO AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC AT 30 TO 40 KT...WITH MAXIMUM SEAS OF 16 FT NEAR 14N96W. THE GRADIENT WILL BEGIN TO RELAX AFTER SUNRISE ON WED WITH WINDS DIMINISHING TO A MINIMAL GALE WHICH WILL PERSIST THROUGH SUNRISE THU THEN QUICKLY DIMINISH TO 20 TO 25 KT THU AFTERNOON. ALTHOUGH THE NORTHERLY WINDS WILL FURTHER DIMINISH TO 10 TO 15 KT THU EVENING... EXPECT ANOTHER N SURGE TO 20 TO 25 KT LATE THU NIGHT CONTINUING THROUGH SUNRISE FRI. ONE LAST SURGE AT ONLY 10 TO 15 KT EXPECTED LATE FRI NIGHT INTO MID MORNING ON SAT. GULF OF PAPAGAYO...ENE WINDS WILL INCREASE TO 20 TO 25 KT IN AND JUST DOWNSTREAM OF THE GULF OF PAPAGAYO LATE TONIGHT AND EXTEND AS FAR W AS 10N88W. THE GRADIENT WILL INCREASE WITH THE WESTERN EXTENT NEAR 09N92W ON WED AND NEAR 08N93W ON THU AS SEAS GRADUALLY BUILD TO 10 FT. LITTLE CHANGE EXPECTED THROUGH THE WEEKEND. GULF OF PANAMA...NORTHERLY WINDS WILL INCREASE TO 15 TO 20 KT LATE TONIGHT AND CONTINUE THROUGH LATE FRI. THE LARGE SWELLS GENERATED IN AND DOWNSTREAM OF THE GULFS OF TEHUANTEPEC AND PAPAGAYO WILL MERGE COVERING THE TROPICAL WATERS FROM 03N TO 11N BETWEEN 93W AND 108W ON THU WITH COMBINED SEAS OF 7 TO 10 FT. THE AFFECTED AREA WILL SHIFT W COVERING THE WATERS FROM 03N TO 10N BETWEEN 88W AND 117W BY LATE FRI. THE UPPER FLOW IS ZONAL ACROSS THE DISCUSSION AREA N OF 10N BETWEEN 110W AND 140W AND IS ADVECTING UPPER MOISTURE ACROSS THE AREA FROM 15N TO 32N BETWEEN 117W AND 125W. OTHERWISE THE UPPER LEVELS APPEAR DRY ACROSS THE SUBTROPICS. AN UPPER TROUGH IS NOTED S OF 10N ALONG 118W...AND IS EFFECTIVELY SEPARATING THE UPPER FLOW OVER THE DEEP TROPICS. WEAK UPPER DIFFLUENCE HAS SOMEWHAT SUPPORTED THE CLUSTERS OF CONVECTION PREVIOUSLY MENTIONED...WITH THE RESULTANT UPPER MOISTURE ADVECTED NE FROM THE EQUATOR TO 11N BETWEEN 102W AND 116W. A BROAD UPPER RIDGE DOMINATES THE TROPICS E OF 102W...WITH THE UPPER RIDGE AXIS IN PHASE WITH THE PREVIOUSLY DESCRIBED LOWER LEVEL AXIS OF THE MONSOON TROUGH AND ITCZ...WITH CONVECTIVE CLUSTERS FLARING ALONG 06N BETWEEN THE COLOMBIAN COAST AND 95W. A BROAD SURFACE RIDGE DOMINATES THE NW PORTION OF THE DISCUSSION AREA WITH HIGH PRESSURE CENTERS ANALYZED AT 26N139W AND 30N126W. THE HIGHS WILL MERGE AND SHIFT EAST ALLOWING A WEAK COLD FRONT OVER THE NW WATERS TO ADVANCE E... BUT ONLY BE ACCOMPANIED BY A SW TO W TO NW WIND SHIFT. A SECOND STRONGER COLD FRONT WILL REACH 32N140W ON THU AFTERNOON...AND EXTEND FROM 32N133W TO 26N135W ON FRI AFTERNOON. THIS FRONT WILL BE ACCOMPANIED BY W TO NW 20 TO 25 KT WINDS AND LARGE SWELLS WHICH WILL DRIVE UP THE COMBINED SEAS TO 8 TO 13 FT OVER THE NW WATERS ON FRI. $$ NELSON