000 AXPZ20 KNHC 170931 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT JAN 17 2015 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 0900 UTC. ...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...A STRONG COLD FRONT IS CURRENTLY MOVING ACROSS THE THE BAY OF CAMPECHE. THIS WILL FUNNEL STRONG WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC...WITH WINDS RAPIDLY INCREASING TO GALE FORCE BY EARLY THIS MORNING. BOATERS CROSSING THE GULF OF TEHUANTEPEC SHOULD EXERCISE EXTREME CAUTION TODAY AS THE GAP WIND EVENT STARTS. WINDS ARE EXPECTED TO SUDDENLY INCREASE TO 40 KT BY THIS AFTERNOON BUILDING SEAS TO 12-13 FT DOWNSTREAM OF THE GULF. MINIMAL GALE FORCE WINDS ARE EXPECTED TO PERSIST TONIGHT INTO MON MORNING. THEN...A REINFORCING PUSH OF COLD AIR IS EXPECTED TO OCCUR MON EVENING AND MON NIGHT. THIS WILL BRING A STRONGER GAP WIND EVENT WITH NORTHERLY WINDS OF 40-45 KT AND BUILDING SEAS UP TO 17 FT BY TUE MORNING. NE TO E SWELL ASSOCIATED WITH THIS EVENT COMBINED WITH A GALE WIND EVENT OVER THE GULF OF PAPAGAYO IS FORECAST TO PRODUCE A VERY LARGE AREA OF SEAS 8 FT OR GREATER THAT WILL LIKELY EXTEND SW TO BEYOND 100W. GULF OF PAPAGAYO GALE WARNING...A STRONG HIGH PRES BUILDING ACROSS THE GULF OF MEXICO AND THE WESTERN CARIBBEAN IN THE WAKE OF THE AFOREMENTIONED STRONG COLD FRONT WILL SUPPORT MINIMAL GALE FORCE WINDS ACROSS THE GULF OF PAPAGAYO LATE MON NIGHT INTO TUE MORNING WITH SEAS BUILDING TO 11-12 FT DOWNSTREAM OF THE GULF TO BEYOND 90W. A GALE WARNING HAS BEEN ISSUED FOR THIS GULF WITH THIS FORECAST PACKAGE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A SURFACE TROUGH EXTENDS FROM 06N88W TO 05N103W. THE ITCZ AXIS CONTINUES FROM 05N103W TO 06N112W TO 04N125W TO 06N135W TO 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 03N TO 05N BETWEEN 123W TO 128W...AND FROM 05N TO 07N BETWEEN 131W AND 137W. ...DISCUSSION... A 1024 MB HIGH PRES IS CENTERED NEAR 30N125W WITH A RIDGE AXIS EXTENDING SE TO JUST BEYOND THE REVILLAGIGEDO ISLANDS. THE PRESSURE GRADIENT BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ CONTINUES TO SUPPORT AN AREA OF FRESH TO STRONG TRADE WINDS FROM 07N TO 15N W OF 120W WITH SEAS TO AROUND 12 FT BASED ON THE MOST RECENT ALTIMETER PASSES. THE HIGH PRESSURE WILL REMAIN QUASI STATIONARY OVER THE NEXT COUPLE OF DAYS BLOCKING ANY FRONTS FROM MOVING TOO FAR TO THE EAST. THE PRES GRADIENT BETWEEN THE ABOVE RIDGE AND A TROUGH OVER NW MEXICO WILL PRODUCE FRESH TO LOCALLY STRONG NW WINDS IN THE GULF OF CALIFORNIA THROUGH EARLY MON. LATEST ASCAT PASS PROVIDED OBSERVATIONS OF NW WINDS IN THE 20-25 KT RANGE ACROSS THE GULF OF CALIFORNIA BETWEEN 24N-28N. A COLD FRONT IS NEAR 30N140W. FRESH TO STRONG SOUTHERLY WINDS ARE NOTED PER SCATTEROMETER DATA AHEAD OF THE FRONT AND NW OF LINE FROM FROM 30N135W TO 28N140W. THIS FRONT WILL NOT PROGRESS TOO FAR EAST AS THE HIGH PRES OVER THE N WATERS REMAINS NEARLY STATIONARY. THE FRONT IS FORECAST TO DISSIPATE OVER THE FAR NW CORNER OVER THE NEXT 36-48 HOURS. LARGE AND LONG PERIOD NW SWELL...23-25 SECONDS...WILL CONTINUE TO PROPAGATE ACROSS THE FORECAST AREA TODAY. THE LEADING EDGE OF THIS SWELL EVENT WILL REACH THE PACIFIC COAST OF BAJA CALIFORNIA THIS MORNING AND AFTERNOON...AND THE REVILLAGIGEDO AND LAS TRES MARIAS ISLANDS THIS EVENING. THIS VERY LONG PERIOD SWELL MOVING THROUGH THE FORECAST WATERS WILL GENERATE HAZARDOUS MARINE CONDITIONS AND DANGEROUS SURF CONDITIONS ACROSS THE REEFS... SHOALS AND COASTAL ZONES OF THE BAJA CALIFORNIA PENINSULA AND THE ABOVE MENTIONED ISLANDS. BY TONIGHT...THIS SWELL EVENT WILL MERGE WITH LONG PERIOD...17-18 SECONDS...CROSS EQUATORIAL SW SWELL CURRENTLY AFFECTING THE WATERS E OF 110W. FRESH TO STRONG NORTHERLY WINDS ARE ALSO EXPECTED ACROSS THE GULF OF PANAMA AND DOWNSTREAM TO NEAR 3N-4N LATE MON NIGHT INTO TUE MORNING AS STRONG HIGH PRES BUILDS ACROSS THE GULF OF MEXICO AND THE WESTERN CARIBBEAN. EXPECT BUILDING SEAS OF 8-10 FT WITH THESE WINDS. FRESH NE WINDS ARE FORECAST ACROSS THE GULF OF FONSECA MON NIGHT AND TUE NIGHT. $$ GR