000 AXPZ20 KNHC 031006 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN APR 03 2016 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 0945 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A 1026 MB HIGH CENTER LOCATED JUST W OF TAMPICO EXTENDS A RIDGE SSE TO OVER SOUTHEASTERN MEXICO. THE ASSOCIATED TIGHT PACKING OF ISOBARS OVER THAT PART OF MEXICO AS NOTED ON THE 06 UTC SURFACE ANALYSIS SUGGESTS THAT STRONG TO GALE FORCE N-NE WINDS ARE FUNNELING S THROUGH THE CHIVELA PASS...AND OUT TO OVER THE GULF OF TEHUANTEPEC. THE LEADING ARC CLOUD OF THESE WINDS IS SEEN ON SATELLITE IMAGERY PROPAGATING SW WELL S OF THE GULF. THESE WINDS ARE IN THE RANGE OF 30-40 KT WITH SEAS OF 9-14 FT...AND ARE WITHIN 45 NM EITHER SIDE OF A LINE FROM 16N95W TO 15N95W TO 14N95.5W TO 13.5N96W. N- NE 25-30 KT ARE ELSWHERE WITHIN 75 NM EITHER SIDE OF A LINE FROM 16N95W TO 14.5N95W TO 13.5N96W WITH SEAS OF 8-12 FT. THE 30-40 KT WINDS ARE EXPECTED TO DIMINISH SLIGHTLY THIS AFTERNOON...THEN INCREASE AGAIN TO 40 KT TONIGHT WITH SEAS IN THE 10-15 FT. NE SWELL WILL SPREAD DOWNSTREAM FROM THE GULF REACHING TO NEAR 09N BETWEEN 93W-100W BY LATE TONIGHT WHERE IT BEGINS TO MIX WITH THE LEADING EDGE OF A LONG PERIOD NW SWELL COMPONENT. SEAS WITHIN THIS AREA ARE FORECAST TO BE 8-10 FT. WITH THE 1026 MB HIGH CENTER WEAKENING ON MON AFTERNOON...THE TIGHT PRES GRADIENT OVER SOUTHEASTERN MEXICO WILL SLACKEN ALLOWING FOR THE GALE FORCE WINDS TO DROP TO JUST UNDER 35 KT AT THAT TIME. THE DOWNSTREAM NE SWELL WILL REACH TO NEAR 08N BETWEEN 93W-102W AS IT CONTINUES TO MIX WITH THE NW SWELL TO PRODUCE SEAS OF 8-9 FT THERE. BY LATE MON NIGHT...A SLIGHT STRENGTHENING OF THE PRES GRADIENT IS FORECAST TO BRING ANOTHER ROUND OF GALE FORCE WINDS THROUGH A NARROW SWATH ACROSS THE GULF WITH SEAS AROUND THE RANGE OF 9-12 FT. A MIX OF NE AND NW SWELL WELL DOWNSTREAM FROM THE GULF WILL KEEP SEAS OF 8-9 FT FROM 07N-13N BETWEEN 96W-107W. THE GALE FORCE WINDS THEN DIMINISH TO JUST BELOW GALE FORCE ON TUE AFTERNOON. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 04N110W TO 03N118W TO 01N125W TO 01N134W. NO SIGNIFICANT CONVECTION IS OBSERVED. ...DISCUSSION... HIGH PRES OF 1023 MB CENTERED NEAR 30N126W EXTENDS A RIDGE SE TO 22N121W AND TO NEAR 15N110W. THE PRES GRADIENT BETWEEN THIS AREA OF HIGH PRES AND LOWER PRES IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH NE TRADES OVER THE WESTERN WATERS FROM 05N TO 13N W OF 128W. A WEAK SURFACE TROUGH IS ALONG A POSITION FROM 05N136W TO 01N140W. ENHANCED CONVERGENCE BETWEEN THE HIGH PRES AND THE TROUGH IS ALLOWING FOR WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS W OF THE TROUGH. A DISSIPATING SURFACE TROUGH EXTENDS FROM A 1020 MB LOW AT 32N131W SE TO 30N130W AND SW TO 24N135W. A COLD FRONT HAS JUST CROSSED THE FAR NW CORNER OF THE AREA...AND IS SUPPORTED BY A STRONG UPPER TROUGH THAT IS JUST NW OF THE AREA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE POSSIBLE N OF 27N W OF 137W. THE FRONT IS FORECAST TO QUICKLY WEAKEN OVER THE NW WATERS ON MON. STRONGER HIGH IS FORECAST BY THE GLOBAL MODELS TO BUILD OVER MUCH OF THE CENTRAL AND WESTERN WATERS LATE MON INTO TUE. THE RESULTANT TIGHT PRES GRADIENT OVER THE FAR WESTERN WATERS WILL ALLOW FOR STRONG NE TRADES THERE WITH SEAS OF 8-9 FT. NW SWELL IS PROPAGATING THOUGH THE AREA AND MERGING WITH SHORTER PERIOD NE SWELL WITH SEAS GREATER THAN 8 FT COVERING MUCH OF THE FORECAST WATERS N OF 06N W OF 120W. THE NW SWELL WILL SUBSIDE OVER THE FORECAST WATERS OVER THE NEXT COUPLE OF DAYS. BY EARLY MON COVERAGE OF SEAS GREATER THAN 8 FT WILL SHRINK TO AN AREA FROM 05N TO 16N W OF ABOUT 131W. GAP WINDS...HIGH PRES FORECAST TO BUILD OVER THE GULF OF MEXICO OVER THE NEXT COUPLE OF DAYS WILL ALLOW FOR NE-E 20-25 KT WINDS OVER THE GULF OF PAPAGAYO BY EARLY MON. WINDS OVER THE GULF OF PAPAGAYO WILL THEN PULSE TO NEAR 25 KT EACH NIGHT...AND DIMINISH TO 15-20 KT DURING THE DAYTIME HOURS THROUGH MIDWEEK. $$ AGUIRRE