000 AXPZ20 KNHC 170323 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...SPECIAL FEATURES... A GALE WARNING WILL GO INTO EFFECT FOR THE GULF OF TEHUANTEPEC EARLY SUN MORNING. A COLD FRONT WILL MOVE RAPIDLY ACROSS THE GULF OF MEXICO THROUGH EARLY SUNDAY. THIS WILL FUNNEL STRONG WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC LATER TONIGHT WITH WINDS RAPIDLY INCREASING TO GALE FORCE BY EARLY MORNING. THE START OF THIS GALE FORCE WIND EVENT WILL BE PARTICULARLY DANGEROUS DUE TO THE SUDDEN ONSET OF JUST BELOW STRONG GALE FORCE WINDS BOATERS CROSSING THE GULF OF TEHUANTEPEC SHOULD EXERCISE EXTREME CAUTION LATE TONIGHT/EARLY SUNDAY MORNING AS THE GAP WIND EVENT STARTS. WINDS ARE EXPECTED TO DIMINISH BELOW GALE FORCE BY EARLY MON MORNING...BUT WILL SUDDENLY INCREASE AGAIN MON EVENING/NIGHT AS A REINFORCING PUSH OF COLD AIR IS EXPECTED. THE FIRST GALE WILL GENERATE SEAS OF 13 FT. HOWEVER...MARINE GUIDANCE SUGGESTS NORTHERLY WINDS COULD REACH STRONG GALE MON NIGHT WITH SEAS TO 16 FT. SEE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A SURFACE TROUGH EXTENDS FROM 7N93W 5N98W TO 5N104W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 5N110W 4N125W TO 4N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS FROM 3N TO 5N BETWEEN 123W TO 135W...AND FROM 5N TO 7N BETWEEN 131W AND 137W. ...DISCUSSION... A 1023 MB HIGH 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 6N TO 12N W OF 134W WITH SEAS TO 11 FT. 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 LATER TONIGHT THROUGH EARLY MON. A PREVIOUS COLD FRONT HAS DISSIPATED OVER THE NW PORTION OF THE AREA. A SECOND COLD FRONT WILL REACH 30N140W TONIGHT WITH SW STRONG WINDS AHEAD OF THIS SECOND FRONT AND WILL DIMINISH AGAIN LATER TONIGHT. THIS FRONT WILL AGAIN NOT PROGRESS TOO FAR BEFORE STALLING AN DISSIPATING DUE TO THE STRONG HIGH PRESSURE TO THE E. THESE FRONTS ARE USHERING IN A SET OF LARGE AND LONG PERIOD NW SWELL...20 SECONDS...WHICH WILL PROPAGATE SE ACROSS THE FORECAST WATERS THROUGH THIS WEEKEND. THE LEADING EDGE OF THIS SWELL WILL REACH THE PACIFIC COAST OF BAJA CALIFORNIA NORTE LATE TONIGHT AND MEXICO S OF 20N BY MON MORNING. 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 AND MON. LOOKING AHEAD...AS PREVIOUSLY MENTIONED A SECOND AND STRONGER GALE GAP WIND EVENT IS EXPECTED ACROSS THE GULF OF TEHUANTEPEC BY MON EVENING. A STRONG HIGH PRES WILL BUILD ACROSS THE GULF OF MEXICO AND THE WESTERN CARIBBEAN BY EARLY MON RESULTING IN A TIGHT PRES GRADIENT ACROSS THE GULF OF PAPAGAYO AND GULF OF PANAMA. THIS WILL INCREASE THE WINDS TO STRONG IN THE GULF OF PAPAGAYO AND FRESH IN THE GULF OF PANAMA IN TO MON NIGHT. $$ PAW