000 AXPZ20 KNHC 311550 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN OCT 31 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE WAS ANALYZED FROM 09N80W TO 07N90W TO 10N110W TO 08N120W TO 11N130W TO 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 08N79W TO 07N82W TO 09N83W. ISOLATED MODERATE AND STRONG CONVECTION IS FLARING OVER THE AREA FROM 08N TO 15N BETWEEN 107W AND 120W. ...DISCUSSION... AN UPPER TROUGH DOMINATES THE NW PORTION WITH ITS MEAN AXIS ENTERING THE AREA AT 32N130W AND EXTENDING SW TO AN EMBEDDED UPPER CYCLONE AT 26N1367W...WITH THE TROUGH THEN CONTINUING S BECOMING SLIGHTLY NEGATIVE TILT TO A BASE OVER THE PACIFIC ITCZ AT 09N134W. A THIN BAND OF UPPER MOISTURE PRECEDES THE DESCRIBED TROUGH AXIS AND EXTENDS E ACROSS SOUTHERN CALIFORNIA AND NEVADA. DENSER UPPER MOISTURE IS NOTED FURTHER W BEHIND THE TROUGH AXIS AND IS ALREADY REACHING THE SW CONUS. PRONOUNCED UPPER DRY AIR IS ROTATING THROUGH THE BASE OF THE TROUGH AND A LITTLE FURTHER E OF THE DESCRIBED TROUGH AXIS...ROUGHLY WITHIN 180 NM EITHER SIDE OF LINE 15N140W TO 21N135W TO 28N123W. AN UPPER ANTICYCLONE IS NOTED OVER THE TROPICAL PACIFIC AT 16N108W WITH A RIDGE AXIS EXTENDING W TO 14N120W. A RIDGE AXIS IS ALSO AMPLIFYING N OVER NEW MEXICO AT 34N108W. UPPER DIFFLUENCE UNDER THIS RIDGE HAS ENHANCED ISOLATED CONVECTION FROM 08N TO 15N BETWEEN 107W AND 120W...AND ALSO WITHIN 30 NM EITHER SIDE OF A OF LINE FROM 14.5N90W TO 15N102.5W TO 13N105W. THE DEBRIS MOISTURE IS FOR THE MOST PART TRAPPED UNDER THE RIDGE FROM 07N TO 20N. HOWEVER...A TROPICAL MOISTURE PLUME...FROM PREVIOUS ITCZ CONVECTION...CONTINUES TO SPREAD N AND NE ALONG THE W PERIPHERY OF THIS UPPER RIDGE...WITHIN 120 NM EITHER SIDE OF LINE FROM 17N127W TO ACROSS THE BAJA CALIFORNIA PENINSULA N OF 27N AND THEN CONTINUES E ACROSS NORTHERN OLD MEXICO... SOUTHERN ARIZONA AND NEW MEXICO...EVENTUALLY DRYING OUT OVER NW TEXAS. AN UPPER CYCLONE IS OBSERVED OVER OLD MEXICO AT 25N103W WITH A TROUGH EXTENDING S TO OVER THE E PACIFIC AT 17N104W AND IS LIKELY CONTRIBUTING TO THE LINE OF CONVECTION FROM 13N TO 15N BETWEEN 90W AND 105W. A UPPER CYCLONE IS SHIFTING SW OVER THE YUCATAN PENINSULA WITH A TROUGH EXTENDING SW TO 07N101W AND INTO ANOTHER UPPER CYCLONE OVER THE DEEP TROPICS AT 02N113W. A TROPICAL RIDGE EXTENDS W ACROSS NORTHERN COLOMBIA AND CENTRAL AMERICA TO A CREST NEAR 10N89W. CONVECTION IS ENHANCED ALONG THE COASTS OF COLOMBIA... PANAMA AND COSTA RICA AND OVER THE SW CARIBBEAN BUT THE DEBRIS MOISTURE IS MINIMAL AND ADVECTED N AND NE OVER THE N CENTRAL CARIBBEAN ISLANDS. GAP WINDS... THE LAST NORTHERLY SURGE TO 20 KT SHOULD CEASE BY MIDDAY TODAY IN AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC. EASTERLY WINDS AT 15 TO 20 KT ARE SURGING ACROSS THE GULF OF PAPAGAYO BUT IS EXPECTED TO DIMINISH EARLY TONIGHT. ELSEWHERE AT THE SURFACE...HIGH PRES 1021 MB IS CENTERED NEAR 30N126W WITH A GRADUAL RIDGE EXTENDING SE TO NEAR 12N110W. A RIDGE ALSO EXTENDS W TO BEYOND 27N140W. THE PRES GRADIENT WILL TIGHTEN A LITTLE LATER TODAY RESULTING IN NW WINDS OF 15 TO 20 KT IN THE SOUTHERN GULF OF CALIFORNIA AND WITHIN ABOUT 240 NM W OF THE BAJA CALIFORNIA PENINSULA. THE AREA OF STRONGEST WINDS WILL SHIFT N OVER THE N GULF OF CALIFORNIA TUE AT 20 TO 25 KT. NW SWELLS WILL ARRIVE AT THE 30N140W BOUNDARY LATE MON DRIVING COMBINED SEAS HEIGHTS TO 20 FT NEAR 30N140W TUE AFTERNOON. SEAS 12 FT OR GREATER WILL REACH THE N BAJA CALIFORNIA PENINSULA WED AND REACH THE TROPICAL WATERS NEAR 10N130W LATE THU. MAY SEE AN INCREASE IN SW FLOW OVER THE PACIFIC WATERS S OF 08N E OF 100W BY MID WEEK DEPENDING ON THE STRENGTH AND TRACK OF TROPICAL CYCLONE TOMAS IN THE E CARIBBEAN. $$ NELSON