000 AXPZ20 KNHC 122153 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC MON NOV 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 06N77W THEN RUNS OVER AND PARALLEL TO THE PACIFIC COAST OF COSTA RICA...THEN TURNS W THROUGH 07N94W TO A 1009 MB EMBEDDED LOW PRES AT 09N112W...THEN DIPS SW TO 08N117W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ WIGGLES W THROUGH ANOTHER 1009 MB EMBEDDED LOW PRES AT 09N125W TO AN EMBEDDED LOW LEVEL TROUGH THAT EXTENDS FROM 09N136W TO 16N131W. THE ITCZ AXIS RESUMES SW OF THE TROUGH AND CONTINUES W TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 90 NM OF THE LOW AT 09N111.5W AND ALSO NOTED WITHIN 120 NM EITHER SIDE OF A LINE FROM 04N78W TO 07N86W... WITHIN 90 NM OF 08.5N115W AND 09N123W...AND WITHIN 30 NM OF 09.5N126W AND 08.5N133W. GALE FORCE WINDS ARE INDICATED WITHIN 240 NM NW OF THE TROUGH EMBEDDED IN THE ITCZ FROM 09N136W TO 16N131W WITH SEAS OF 12 TO 17 FT. EXPECT WINDS TO QUICKLY DIMINISH BELOW GALE FORCE TONIGHT. ...DISCUSSION... A SHORTWAVE RIDGE DOMINATES THE UPPER LEVELS ORIGINATING FROM AN UPPER ANTICYCLONE CENTERED AT 15N117W...WITH AN UPPER RIDGE EXTENDING W TO A CREST AT 15N130W...AND AN UPPER RIDGE EXTENDING E TO A CREST AT 13N84W. AN UPPER SHORTWAVE TROUGH IS CURRENTLY POSITIONED NW OF THE AREA. UPPER DEBRIS MOISTURE...ORIGINATING FROM ITCZ CONVECTION IN THE CENTRAL PACIFIC...IS ADVECTED E AND NE THROUGH THE UPSTREAM TROUGH INTO THE AREA WITHIN 120 NM EITHER SIDE OF A LINE FROM 13N140W TO 20N132W. THIS MOISTURE FANS OUT AS MOVES E ACROSS THE UPPER RIDGE BECOMING AN IMPRESSIVE TROPICAL PLUME COVERING THE AREA FROM 15N-31N BETWEEN 132W-105W. UPPER DIFFLUENCE S OF THE UPPER RIDGE IS ENHANCING THE CONVECTIVE CLUSTERS PREVIOUSLY DESCRIBED BETWEEN 106W-128W. AN UPPER TROUGH DISSECTS THE CARIBBEAN FROM NE-SW TO BASE OVER PANAMA SETTING UP AN ARE OF UPPER DIFFLUENCE OVER THE EXTREME SE PORTION OF THE DISCUSSION AREA...AND ENHANCING THE CONVECTION PREVIOUSLY MENTIONED BETWEEN 78W-86W. THE UPPER RIDGE WILL WEAKEN OVER THE NEXT FEW DAYS ALLOWING THE UPPER TROUGH NW OF THE AREA TO MOVE INTO THE FAR NW PORTION TUE NIGHT DRIVING A SURFACE FRONT INTO THE AREA LATE TUE ACCOMPANIED BY 15-20 KT SW-W-NW WIND SHIFT...WITH SEAS BUILDING 6-9 FT W OF THE FRONT. AN AMPLIFYING SHORTWAVE TROUGH OVER THE CONUS WILL DIG S ACROSS THE GULF OF MEXICO TO A BASE OVER THE PACIFIC NEAR 12N96W. THIS RESULT IN STRONG SW-W-NW UPPER LEVEL WINDS TO PERSIST OVER THE DISCUSSION AREA TO THE N OF 17N. A BROAD INVERTED UPPER TROUGH OVER THE DEEP TROPICS NEAR 107W WILL SHIFT WESTWARD...AND CONTINUE TO SEPARATE THE UPPER FLOW OVER THE AREA S OF 17N. GULF OF TEHUANTEPEC...NORTHERLY WINDS AT 20-25 KT HAVE BEGUN TO SURGE THROUGH THE ISTHMUS OF TEHUANTEPEC. EXPECT THESE WINDS TO RAPIDLY INCREASE TO A 30-40 KT GALE OVER THE NEXT FEW HOURS...WITH SEAS BUILDING TO 10-15 FT BY EARLY TUE. THIS TEHUANTEPEC EVENT IS EXPECTED TO LAST THROUGH EARLY THU. BAJA CALIFORNIA AREA...SURFACE WINDS HAVE CLOCKED TO NNE ALONG WESTERN BAJA CALIFORNIA AND SEAS HAVE SUBSIDED TO 3-5 FT. WINDS AND SEAS WILL CONTINUE TO DIMINISH/SUBSIDE THROUGH MID WEEK. NW WINDS AT 20-30 KT ARE CURRENTLY OBSERVED OVER THE GULF OF CALIFORNIA N OF 22N. THESE WINDS WILL QUICKLY DIMINISH TO 15-20 KT ON TUE. GULF OF PAPAGAYO...NE WINDS AT 15-20 KT WINDS...WITH SEAS 4-7 FT...ARE EXPECTED TO CONTINUE TO SURGE THROUGH A GAP IN THE CORDILLERA INTO AND JUST DOWNSTREAM...TO NEAR 09N92.5W...OF THE GULF OF PAPAGAYO TONIGHT...THEN INCREASING TO 20-25 KT ON TUE AND CONTINUING TO PULSE THROUGH AT LEAST MID WEEK. $$ NELSON