000 AXPZ20 KNHC 160935 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT JAN 16 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 0900 UTC. ...SPECIAL FEATURES... A GALE WARNING IS IN EFFECT FOR THE GULF OF TEHUANTEPEC. A COLD FRONT WILL MOVE RAPIDLY ACROSS THE GULF OF MEXICO LATE SATURDAY INTO EARLY SUNDAY. STRONG WINDS WILL FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC BY EARLY SUNDAY MORNING WITH WINDS RAPIDLY INCREASING TO GALE FORCE. THE START OF THIS GALE FORCE WIND EVENT WILL BE PARTICULARLY DANGEROUS DUE TO THE SUDDEN ONSET OF GALE FORCE WINDS AS WINDS INCREASE FROM 5 TO 10 KT AROUND 0600 UTC SUNDAY TO NEAR 40 KNOTS BY 1200 UTC SUNDAY. BOATERS CROSSING THE GULF OF TEHUANTEPEC SHOULD EXERCISE EXTREME CAUTION LATE SATURDAY NIGHT/EARLY SUNDAY MORNING AS THE GAP WIND EVENT STARTS. WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY MON MORNING...BUT WILL SUDDENLY INCREASE AGAIN MON EVENING AND MON NIGHT AS A REINFORCING PUSH OF COLD AIR IS EXPECTED. MARINE GUIDANCE SUGGESTS NORTHERLY WINDS NEAR 45 KT AND BUILDING SEAS OF 16-17 FT AROUND 0600 UTC TUE. SEE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS EXTENDS FROM 05N96W TO 07N107W TO 04N120W TO 05N135W TO 03N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 60 NM N OF AXIS BETWEEN 131W AND 135W. SIMILAR CONVECTION IS NEAR 02N137W. ...DISCUSSION... A 1024 MB HIGH PRES IS CENTERED NEAR 28N125W WITH A RIDGE EXTENDING SE TO NEAR THE REVILLAGIGEDO ISLANDS. THE PRESSURE GRADIENT BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS SUPPORTING AN AREA OF FRESH TO STRONG TRADE WINDS FROM 08N TO 17N W OF 120W...AND FROM 09N TO 13N BETWEEN 112W AND 120W. THE MOST RECENT SCATTEROMETER DATA CONFIRMED THE PRESENCE OF THESE WINDS. SEAS ARE IN THE 8-11 FT RANGE WITHIN THE AREA OF THE TRADES PER A COUPLE OF ALTIMETER PASSES. THE HIGH PRESSURE CENTER WILL SLOWLY DRIFT NE OVER THE NEXT 48 HOURS. THIS WILL LOOSEN THE PRESSURE GRADIENT SLIGHTLY AND THE AERIAL EXTENT OF THE TRADES WILL DECREASE SOME. THE PRES GRADIENT BETWEEN THE RIDGE AND A TROUGH OVER NW MEXICO IS NOW PRODUCING FRESH TO LOCALLY STRONG NW WINDS JUST OFF BAJA CALIFORNIA NORTE...PARTICULARLY N OF 28N E OF 117W. FRESH NORTHERLY WINDS ARE ALSO NOTED NEAR CABO CORRIENTES. A COLD FRONT IS OVER THE FAR NW PORTION OF THE AREA AND EXTENDS FROM 30N138W TO 28N140W. THE FRONT WILL NOT PROGRESS VERY FAR INTO THE FORECAST AREA BEFORE STALLING AND DISSIPATING. WINDS HAVE ALREADY DIMINISHED TO 20 KT AHEAD OF THE FRONT. A SECOND COLD FRONT WILL REACH 30N140W TONIGHT. SW WINDS AHEAD OF THIS SECOND FRONT WILL INCREASE TO 20 KT THIS AFTERNOON AND TO 25 KT THIS EVENING AND TONIGHT DUE TO THE TIGHTER PRESSURE GRADIENT BETWEEN THE FRONT AND AREA OF HIGH PRESSURE OVER THE NE WATERS. THESE FRONTS WILL USHER IN A SET OF LARGE AND LONG PERIOD NW SWELL...23 TO 25 SECONDS...WHICH WILL PROPAGATE SE ACROSS THE FORECAST WATERS THROUGH THIS WEEKEND. THE LEADING EDGE OF THE SWELL WILL REACH THE PACIFIC COAST OF BAJA CALIFORNIA ON SUN. 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 ON SUN. THEN...THIS SWELL EVENT WILL REACH THE REVILLAGIGEDO ISLANDS AND LAS TRES MARIAS ISLANDS BY SUN EVENING. EXPECT MAX SEAS UP TO 22 FT ACROSS THE FAR NW CORNER THIS MORNING. LOOKING AHEAD...AS PREVIOUSLY MENTIONED A SECOND AND STRONGER GAP WIND EVENT IS EXPECTED ACROSS THE GULF OF TEHUANTEPEC BY MON NIGHT. AT THIS TIME...WINDS ARE ALSO EXPECTED TO INCREASE TO 20- 30 KT ACROSS THE GULF OF PAPAGAYO...AND TO 20-25 KT ACROSS THE GULF OF PANAMA. THESE EVENTS WILL BE ASSOCIATED WITH A STRONG HIGH PRES BUILDING ACROSS THE GULF OF MEXICO AND THE WESTERN CARIBBEAN AND RESULTING IN A TIGHT PRES GRADIENT ACROSS THESE AREAS. $$ GR