000 AXPZ20 KNHC 300354 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI DEC 30 2011 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 0230 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS ANALYZED FROM SW CARIBBEAN ACROSS CENTRAL AMERICA ENTERING EPAC NEAR 07.5N78W TO 06N96W WHERE IT TRANSITIONS TO ITCZ...CONTINUING TO 07N122W TO 09N130W TO BEYOND 07N140W. NO SIGNIFICANT CONVECTION NOTED NEAR AXIS. ...DISCUSSION... AT UPPER LEVELS...ZONAL FLOW ALOFT HAS RECENTLY PREVAILED N OF THE AREA...N OF 30-35N. HOWEVER...A SHORTWAVE RIDGE HAS BEGUN TO DEVELOP BETWEEN 120W AND 130W N OF 29N. A MIDDLE TO UPPER LEVEL TUTT LIKE AXIS MEANDERING WWD NEAR 30N EXTENDS FROM NRN MEXICO TO NEAR 29N132W...THEN ARCHING SW THEN S AND WEAKLY CONNECTING TO CUT OFF DEEP LAYERED LOW MENTIONED BELOW...CENTERED NEAR 14N144W. UPPER RIDGING CONTINUES TO THE E OF THIS UPPER LOW...WHILE STRONG WLY FLOW TO THE SOUTH OF THE UPPER LOW CONTINUES AND IS CREATING A ZONE OF STRONG DIVERGENCE ALOFT ACROSS THE SE QUADRANT OF THE UPPER LOW...CONTRIBUTING TO DEEP CONVECTION. THIS ASSOCIATED SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS OCCURRING FROM 13N TO 21N BETWEEN 129W AND 139W AND FROM 12N TO 14N BETWEEN 124W AND 129W. AT LOWER LEVELS... GULF OF TEHUANTEPEC...THE LONG-LASTING GAP WIND EVENT FINALLY CAME TO A CLOSE THIS MORNING...AS N WINDS DROPPED BELOW 20 KT. THIS WILL BE A SHORT RESPITE...HOWEVER...AS SOME ENHANCED PRESSURE GRADIENT ACROSS FROM THE GULF OF MEXICO TO THE GULF OF TEHUANTEPEC WILL BEGIN A NEW EVENT SATURDAY MORNING. A RATHER VIGOROUS GULF OF MEXICO COLD FRONT WILL LIKELY BOOST THE GAP WINDS TO GALE FORCE BY SUNDAY NIGHT. THE DURATION OF GALES MAY BE LENGTHY...POSSIBLY FROM SUNDAY NIGHT THROUGH WEDNESDAY. GULF OF PAPAGAYO...GAP WINDS CONTINUE TO FUNNEL ACROSS NICARAGUA AS FRESH TRADEWINDS PERSIST ACROSS MUCH OF THE CARIBBEAN. THESE GAP WINDS SHOULD PEAK EACH OF THE NEXT FEW DAYS IN THE LATE NIGHT AND EARLY MORNING HOURS AT AROUND 25 KT AND 8 FT SEAS. THESE CONDITIONS APPEAR LIKELY TO PERSIST FOR THE NEXT SEVERAL DAYS...WITH THE WIND PLUME STRETCHING DOWNWIND TO BEYOND 95W BY SUNDAY EVENING. GULF OF CALIFORNIA...AS IS TYPICAL...THERE WERE NO OVER WATER OBSERVATIONS THROUGHOUT THE GULF WATERS TO CONFIRM COMPUTER MODEL FORECASTS...BUT GLOBAL MODELS INDICATE WINDS HAVE DIMINISHED TO LESS THAN 20 KT THROUGHOUT THE LENGTH OF THE BASIN...AND WILL REMAIN SO THROUGH EARLY SUN...WHEN THE REGIONAL GRADIENT WILL INCREASE IN ASSOCIATION WITH A GULF OF MEXICO COLD FRONT. A COMPLEX SURFACE TROUGH IS ANALYZED ALONG 138W/139W FROM 12N TO 20N... ASSOCIATED WITH PERSISTENT CONVECTION OCCURRING ACROSS THE ERN SEMICIRCLE OF THE CUT OFF LOW MENTIONED ABOVE. THE COMBINATION OF THE TROUGH AND A 1026 MB HIGH NEAR 31N139W IS CAUSING A RATHER BROAD ZONE OF 20-25 KT TRADEWINDS GENERALLY BETWEEN 10N AND 24N W OF 130W. PEAK TRADEWINDS ACROSS THIS ZONE ARE AROUND 25 KT AND PEAK SIGNIFICANT WAVE HEIGHTS NEAR 12 FT. THE TROUGH SHOULD ADVECT WESTWARD AND WEAKEN AS THE UPPER LOW OPENS UP AND SHIFTS EASTWARD OVER THE NEXT TWO DAYS. OTHERWISE...NO SIGNIFICANT WAVE HEIGHTS ABOVE 12 FT ARE CURRENTLY FOUND IN THE AREA OF RESPONSIBILITY. ALTHOUGH A FEW NEW PULSES OF NW SWELL WILL MOVE INTO THE AREA DURING THE NEXT FEW DAYS...THE NEXT LARGE LONG-PERIOD SWELL EVENT SHOULD REACH THE NW BORDER OF OUR AREA BEGINNING SUNDAY EVENING....WITH SEAS IN EXCESS OF 15 FT MOVING INTO NW PORTIONS OF THE AREA BY MONDAY MORNING. SEAS OVER 12 FT ARE ALSO POSSIBLE BEGINNING EARLY MONDAY IN THE GULF OF TEHUANTEPEC. $$ STRIPLING