000 AXPZ20 KNHC 112156 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN NOV 11 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 ACROSS THE SOUTHERN GULF OF PANAMA TO THE COSTA RICA BORDER AT 09N84W WHERE THE TROUGH AXIS TURNS ABRUPTLY SW TO 07N93W...THIN WIGGLES W THROUGH POINTS 09N105W AND 07N111W TO AN EMBEDDED 1011 MB LOW PRES AT 09N118W. ITCZ AXIS FORMS JUST W OF THE EMBEDDED LOW AT 08N120W AND TURNS NW TO 11N130W...THEN W TO BEYOND 10N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED N OF 02N E OF 80W...AND WITHIN 30 NM EITHER SIDE OF A LINE FROM 10N105W TO 08N111W...AND ALSO WITHIN 60 NM EITHER SIDE OF A LINE FROM 13N128W TO 12N132W TO 13N140W. ...DISCUSSION... A LONGWAVE UPPER TROUGH DOMINATES THE SUBTROPICS BETWEEN 95W-150W WITH TWO EMBEDDED SHORTWAVE TROUGHS NOTED. THE EASTERN MOST TROUGH IS OVER N AMERICA ALONG 105W AND EXTENDS S INTO THE DISCUSSION AREA FROM 32N105W TO A BASE AT 19N109W. THE WESTERN MOST UPPER TROUGH EXTENDS FROM 35N139W THROUGH AN EMBEDDED UPPER CYCLONE AT 26N136W...WITH THE TROUGH THEN EXTENDING SW TO 19N145W. AN UPPER ANTICYCLONE IS OVER THE DEEP TROPICS AT 05N134W WITH A SHORTWAVE RIDGE EXTENDING N TO BEYOND 32N126W EVENTUALLY ACROSS THE NW COAST OF THE CONUS. THIS UPPER PATTERN CREATES A LARGE AREA OF UPPER DIFFLUENCE...AND A SOUTHWESTERLY WIND MAXIMA...WITHIN ROUGHLY 360 NM EITHER SIDE OF A LINE FROM 11N135W TO 25N120W. THE RIGHT REAR QUADRANT OF THIS UPPER JET IS IN PHASE AND SUPPORTING THE CONVECTION PREVIOUSLY DESCRIBED BETWEEN 128W-140W. THE RESULTANT DEBRIS MOISTURE IS REINFORCED BY DEBRIS MOISTURE ORIGINATING FROM ITCZ CONVECTION W OF 150W...ALL CONCENTRATING INTO A DENSE TROPICAL PLUME COVERING THE DISCUSSION AREA FROM 10N-27N BETWEEN 132W-120W. THIS MOISTURE WILL CONTINUE E ACROSS THE UPPER RIDGE TONIGHT INTO EARLY MON...THEN ACCELERATE E AND NE INTO THE EASTERNMOST UPPER TROUGH ACROSS CENTRAL OLD MEXICO WHERE A PREVIOUS MOISTURE PLUME IS CURRENTLY EVAPORATING. THIS TROPICAL MOISTURE WILL BECOME SIGNIFICANT IF IT MAINTAINS AND EVENTUALLY FEEDS INTO THE SURFACE FRONT PRECEDING THE SHORTWAVE OVER THE SE CONUS LATE MON. AN UPPER LEVEL ANTICYCLONE IS CENTERED AT 08N96W WITH AN UPPER RIDGE EXTENDING NE ACROSS THE EASTERN GULF OF MEXICO INTO THE LONGWAVE RIDGE COLLAPSING SE ACROSS EASTERN N AMERICA. AN UPPER RIDGE ALSO EXTENDS W FROM THE ANTICYCLONE TO A CREST OVER THE DEEP TROPICS AT 12N110W. UPPER DIFFLUENCE ALONG THIS TROPICAL RIDGE IS ENHANCING THE MONSOON TROUGH CONVECTION ALREADY DESCRIBED BETWEEN 105W-111W...WITH THE DEBRIS MOISTURE ORGANIZING INTO A THIN TROPICAL PLUME NOTED WITHIN 180 NM OF LINE FROM 12N107W TO BEYOND 25N96W...WHERE IT MERGES WITH THE REMNANTS OF ANOTHER TROPICAL PLUME. UPPER DIFFLUENCE IS ALSO ENHANCING E PACIFIC CONVECTION OVER THE EASTERN SEGMENT OF THE MONSOON TROUGH...TO THE N OF 02N E OF 80W...WITH THE DEBRIS MOISTURE NOW ADVECTED S ACROSS THE EQUATOR BETWEEN 80W-85W. OTHERWISE DRY UPPER AIR IS NOTED OVER THE DISCUSSION AREA E OF 100W...AND S OF 07N BETWEEN 100W-130W. AN UPPER CYCLONE IS NOTED OVER THE DEEP TROPICS AT 01N119W WITH AN INVERTED UPPER TROUGH EXTENDING NE TO 06N115W. THIS UPPER TROUGH WILL CONTINUE TO SEPARATE THE UPPER FLOW OVER THE SOUTHERN PORTION OF THE DISCUSSION AREA THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. THE SHORTWAVE UPPER TROUGHS WILL PROGRESS EASTWARD EFFECTIVELY SHIFTING THE PARENT LONGWAVE TROUGH TO OVER EASTERN N AMERICA. THIS WILL RESULT IN STRONG WESTERLY ZONAL UPPER FLOW...AT 50-120 KT...DOMINATING THE ENTIRE DISCUSSION AREA N OF 16N THROUGH EARLY TUE. BY THEN A DEEP LAYERED TROUGH WILL APPROACH THE FAR NW PORTION DRIVING A SURFACE FRONT INTO THE AREA MON NIGHT ACCOMPANIED BY 15-20 KT SW-W-NW WIND SHIFT AND SEAS 6-9 FT. IN THE MEANTIME...SURFACE HIGH PRESSURE HAS BUILT S ACROSS THE SUBTROPICAL AND TROPICAL WATERS N OF 10N TO THE W OF 110W. THE NE TRADES S OF A SURFACE RIDGE FROM 32N127W TO 16N107W HAVE INCREASED TO 20-25 KT...SEAS 8-12 FT...ACROSS THE WATERS FROM 12-24N BETWEEN 118-140W. EXPECT THIS AREA OF ENHANCED TRADES TO SHIFT TO THE W OF 122W ON MON...THEN DIMINISH TO 15-20 KT ON TUE AS SEAS SUBSIDE TO 7-11 FT. BAJA CALIFORNIA AREA...NORTHERLY WINDS AT 15-20 KT...SEAS 6-8 FT...CURRENTLY OBSERVED ALONG WESTERN BAJA CALIFORNIA WILL BEGIN TO DIMINISH TONIGHT AS THE LOW LEVEL WINDS CLOCK FROM N-NE WITH SEAS SUBSIDING TO 2-4 FT ALONG THE ENTIRE W COAST OF BAJA ON MON... WITH LITTLE CHANGE THROUGH MID WEEK. NW WINDS AT 20-25 KT ARE CURRENTLY OBSERVED OVER MOST OF THE GULF OF CALIFORNIA WITH LITTLE CHANGE EXPECTED THROUGH MON AFTERNOON...THEN THE GRADIENT WILL RELAX MAINTAINING ABOUT 15 KT ON WED...AND 10-15 KT ON THU. BEST GUESS IS SEAS WILL MAX AT ABOUT 8 FT OVER THE SOUTHERN GULF IN AREAS OF LONG NW FETCH. GULF OF PAPAGAYO...NE WINDS AT 15-20 KT WINDS...WITH SEAS 6-8 FT...ARE EXPECTED TO CONTINUE TO SURGE THROUGH A GAP IN THE CORDILLERA INTO AND JUST DOWNSTREAM OF THE GULF OF PAPAGAYO THROUGH AT LEAST MID WEEK. THESE EFFECTS ARE NOTED AS FAR W AS 09N91W. GULF OF TEHUANTEPEC...NORTHERLY WINDS AT 15-20 KT WILL DEVELOP IN THE GULF OF TEHUANTEPEC ON MON AFTERNOON...THEN RAPIDLY INCREASE TO GALE FORCE MON NIGHT...WITH SEAS BUILDING TO 10-15 FT EARLY TUE. THIS NEXT TEHUANTEPEC EVENT IS EXPECTED TO LAST THROUGH LATE THU NIGHT. $$ NELSON