000 AXPZ20 KNHC 161006 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC WED AUG 16 2006 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 0945 UTC. SPECIAL FEATURES... .TS HECTOR...NEAR NEAR 13.1N 116.5W 1000 MB AT 0900 UTC AUG 16 MOVING W OR 270 DEG AT 13 KT. MAXIMUM SUSTAINED WINDS 40 KT GUSTS 50 KT. TS FORCE WINDS WITHIN 50 NM N AND 75 NM S SEMICIRCLES. SEAS 12 FT OR GREATER WITHIN 120 NM OF CENTER EXCEPT 150 NM SE QUAD WITH SEAS TO 15 FT. NUMEROUS STRONG CONVECTION IS CONTINUOUS WITHIN 90 NM OF CENTER OVER SE SEMICIRCLE WITH TOPS TO -84C. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED ELSEWHERE WITHIN 210 NM OF CENTER AND MOSTLY IN A NON-CONTINUOUS BAND OVER THE NW QUAD. THE CYCLONE IS MOVING W AND REMAINING JUST TO THE SE OF AN UPPER RIDGE ORIGINATING FROM AN UPPER ANTICYCLONE OVER OLD MEXICO AT 26N104W. THIS UPPER ANTICYCLONE IS EXPECTED TO SHIFT N TO NEAR 30N105W IN 24 HOURS WITH A RIDGE EXTENDING SW GENERALLY JUST TO N OF THE FORECAST TRACK OF THE LOW...WITH THIS RIDGE SCENARIO CONTINUING OVER THE CYCLONE THROUGH 72 HOURS. WITH THE CYCLONE EXPECTED TO SOON GENERATE ITS OWN ANTICYCLONE ALOFT THERE WILL BE PLENTY VENTILATION ALOFT. BUT COOLER WATERS SEA SURFACE TEMPS WILL BE ENCOUNTERED BY DAY 3 AND FORECAST INTENSITIES REFLECT THAT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE ALONG 101W MOVED W 15 KT THE PAST 48 HOURS. A N TO S LINE OF STRONG CONVECTION IS NOTED OVER OLD MEXICO AT 20N SUGGESTING THE WAVE MAY HAVE HIGHER AMPLITUDE THAT 17N. ONLY ISOLATED MODERATE CONVECTION CURRENTLY FLARING OVER THE PAC WATERS WITHIN 30 NM OF THE WAVE AXIS. TROPICAL WAVE ALONG 131W HAS MOVED W 13 KT THE PAST 48 HOURS. BROAD CYCLONIC TURNING IS NOTED ALONG THE WAVE AXIS. CONVECTION ENHANCED WITHIN 120 NM W OF THE WAVE FROM 8N TO 16N. ...ITCZ... ITCZ AXIS ALONG AXIS 6N78W 7N90W 7N108W TO TS HECTOR THEN W TO 10N140W. ISOLATED MODERATE AND STRONG FROM 4N TO 11N E OF 105W AND FROM 8N TO 14N W OF 126W. ...DISCUSSION... A SMALL UPPER ANTICYCLONE IS NEAR 23N133W AND IS ERODING RAPIDLY AS A SHORTWAVE TROUGH MOVES SE OF THE RIDGE. THE TROUGH AXIS LIES ALONG 32N120W THROUGH A SMALL UPPER CYCLONE QUASI STATIONARY AT 25N123W AND CONTINUING S TO A BASE NEAR 17N125W. VERY DRY UPPER AIR IS NOTED ALONG A LINE FROM 35N115W TO 28N124W. DRY UPPER AIR IS W OF THE RIDGE...WITHIN 120 NM EITHER SIDE OF LINE 25N142W 30N134W. GLOBAL MODELS CONTINUE TO HOLD THIS TROUGH STATIONARY...BLOCKED BY THE UPPER ANTICYCLONE OVER OLD MEXICO...MENTIONED IN SPECIAL FEATURE PARAGRAPH ABOVE. ANOTHER UPPER ANTICYCLONE IS NEAR 16N129W WITH A RIDGE EXTENDING SW 14N140W TO A SHARP CREST AT 13N155W. UPPER MOISTURE ORIGINATING FROM ITCZ CONVECTION BETWEEN 123W AND 150W IS ADVECTED NE AROUND THIS RIDGE WITHIN 180 NM EITHER SIDE OF LINE 18N140W TO 27N130W. UPPER DEBRIS MOISTURE ORIGINATING FROM ITCZ CONVECTION BETWEEN 123W AND 110W IS ADVECTED N MERGING WITH DEBRIS MOISTURE FROM TS HECTOR AND CONTINUING N OVER WRN OLD MEXICO AND EVENTUALLY ENE ACROSS THE DESERT SW OF CONUS INTO AN UPPER CYCLONE OVER EXTREME E TEXAS. AN UPPER ANTICYCLONE IS ESTIMATED NEAR 17N77W WITH A WEAK UPPER RIDGE EXTENDING W ACROSS CENTRAL AMERICA INTO THE TROPICAL E PAC TO NEAR 14N92W. DEBRIS MOISTURE FROM ITCZ CONVECTION E OF 90W IS GENERALLY SPREADING N IN RESPONSE TO THIS RIDGE. GAP WINDS...LATEST SSMI AND QUICK SCAT INDICATE THAT NE WINDS 15 TO 20 KT CONTINUE IN AND JUST DOWNSTREAM OF THE GULF OF PAPAGAYO. ALTHOUGH GUIDANCE SUGGESTS ELY 20 KT SURGES WILL CONTINUE FOR ABOUT ANOTHER 24 HOURS THE GRADIENT IN THE W CARIBBEAN SUGGESTS THAT 20 KT SURGES WILL CONTINUE FOR A FEW MORE DAYS. $$ NELSON