000 AXPZ20 KNHC 091009 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON JAN 09 2012 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS EXTENDS FROM 09.5N75W TO LOW PRES NEAR 04.5N79W 1011 MB TO 06N84W TO 03N95W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 06N109W TO 06.5N132W TO BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 270 NM N OF AXIS W OF 120W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS OCCURRING FROM 13N TO 20N W OF 126W...WELL REMOVED FROM THE ITCZ. ...DISCUSSION... A BLOCKING PATTERN ALOFT PERSISTS ACROSS THE AREA THIS MORNING AND IS FORECAST TO FINALLY BREAK DOWN BY THE END OF THE WEEK. CURRENTLY A BROAD UPPER RIDGE COVERS MOST OF THE AREA BETWEEN 105W AND 134W. A SHARP MIDDLE TO UPPER LEVEL TROUGH MEANDERS ACROSS THE NW CORNER OF THE AREA...AND EXTENDS TO A MIDDLE TO UPPER LEVEL CYCLONE NEAR 21N140W...WITH TROUGH AXIS THEN EXTENDING S-SW TO 04N145W. AN 80-100 KT JET SEGMENT WAS NOTED MOVING THROUGH THE SE QUADRANT OF THIS TROUGH THIS MORNING...AND ACROSS SW PORTIONS OF THE AREA. THE ASSOCIATED DOWNSTREAM SWLY FLOW EXTENDS DOWN INTO THE MIDDLE LEVELS OF THE ATMOSPHERE...AND CONTINUES TO INDUCE A BROAD ZONE OF LOW TO MID LEVEL CONVERGENCE LEADING TO THE CONVECTION DESCRIBED ABOVE. THE MID TO UPPER CYCLONE AND ASSOCIATED TROUGH WILL SHIFT SLOWLY E TO NEAR 135W DURING THE NEXT COUPLE OF DAYS...WITH ACTIVE CONVECTION CONTINUING TO THE E OF THIS FEATURE. A 1028 MB HIGH PRES CENTER WAS LOCATED N OF THE AREA NEAR 37N130W WITH RIDGE EXTENDING SE TO NEAR 20N120W. THE PRESSURE GRADIENT BETWEEN THE HIGH AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH TO STRONG TRADEWINDS FROM 07N TO 14N W OF 127W. LONG PERIOD NW SWELL...WITH PERIODS OF 16-19 SECONDS ALONG THE LEADING EDGE OF THE SWELL TRAIN...CONTINUES TO MOVE SE THROUGH THE FORECAST WATERS...WITH COMBINED SEAS 8 TO 10 FT CURRENTLY COVERING MUCH OF THE AREA W OF 100W. THESE SWELLS ARE COMBINING WITH NORTHEASTERLY WIND WAVES GENERATED IN THE ZONE OF FRESH TRADE WINDS TO PRODUCE SEAS OF 9 TO 12 FT...AS VERIFIED BY EARLY EVENING ALTIMETER DATA. THESE NW SWELLS WILL CONTINUE TO PROPAGATE SE...REACHING THE GALAPAGOS ISLANDS ALONG 91W BY LATE THIS MORNING...THEN THE NW COAST OF S AMERICA TUE MORNING...WHILE SLOWLY SUBSIDING. GULF OF PAPAGAYO...FRESH TRADE WINDS OVER THE WESTERN CARIBBEAN ARE FLOWING THROUGH THE GAPS IN THE TOPOGRAPHY OVER NICARAGUA AND COSTA RICA INTO THE GULF OF PAPAGAYO. WINDS WILL PEAK AT 20 TO 25 KT DURING THE EARLY MORNING HOURS WITH THE ADDED COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS AND THEN REDUCE TO AROUND 20 KT THROUGHOUT THE DAY AND EARLY EVENING HOURS. LITTLE CHANGE IN THIS PATTERN IS EXPECTED THROUGH THIS EVENING. AS THE AREA OF HIGH PRESSURE OVER THE SW N ATLC WATERS WEAKENS TONIGHT AND TUESDAY... WINDS OVER THE CARIBBEAN WATERS WILL DIMINISH. THIS WILL DIMINISH WINDS FUNNELING ACROSS THE GULF OF PAPAGAYO...WITH WINDS EXPECTED TO FINALLY DIMINISH BELOW 20 KT BY TUESDAY AFTERNOON. GULF OF CALIFORNIA...HIGH PRESSURE OVER THE GREAT BASIN REGION HAS TIGHTENED THE PRES GRADIENT ACROSS THE NORTHERN GULF OF CALIFORNIA. NWLY WINDS OF 20 TO 30 KT HAVE PREVAILED N OF 26N SINCE SUNDAY AFTERNOON...AND HAVE PEAKED IN INTENSITY. WINDS HAVE DIMINISHED TO 20-25 KT OVERNIGHT...AS VERIFIED BY A 05 UTC ASCAT PASS...AND SPREAD S TO 25N...AND ARE EXPECTED TO CONTINUE TO SPREAD THROUGH THE ENTIRE LENGTH OF THE GULF BY AROUND SUNRISE THIS MORNING. THE AREA OF HIGH PRESSURE OVER THE GREAT BASIN REGION WILL WEAKEN TONIGHT INTO TUESDAY. THIS WILL WEAKEN THE PRESSURE GRADIENT AND DIMINISH WINDS BELOW 20 KT BY TUE AFTERNOON. $$ STRIPLING