000 AXPZ20 KNHC 101555 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU SEP 10 2009 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. ...SPECIAL FEATURE... AT 10/1500 UTC...HURRICANE LINDA IS NEAR 18.4N 130.1W MOVING N NW 0R 330 DEG AT 8 KT. THE MAXIMUM SUSTAINED WINDS ARE 75 KT WITH GUSTS TO 90 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 150 NM OVER THE N AND WITHIN 90 NM OVER THE S SEMICIRCLES OF LINDA'S CENTER. ALTHOUGH LINDA STRENGTHENED SOME THE PAST FEW HOURS...SHE IS EXPECTED TO CONTINUE TO ENCOUNTER WESTERLY SHEAR AND COOLER SEAS SURFACE WATERS ALONG HER TRACK AND IS EXPECTED TO WEAKEN TO A TROPICAL STORM ON FRI AND FURTHER WEAKEN TO A DEPRESSION THIS WEEKEND. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC AND THE PUBLIC ADVISORY UNDER TCPEP5/ WTPZ35 KNHC FOR MORE DETAILS. ...TROPICAL WAVE... A TROPICAL WAVE IS N OF 05N ALONG 94W AND HAS MOVED W AT ABOUT 17 KT OVER THE PAST 24 HOURS. THE WAVE IS MOVING UNDER THE E PERIPHERY OF AN UPPER RIDGE WITH THE ASSOCIATED DIFFLUENCE ENHANCING CONVECTION ALONG THE WAVE AXIS. A LARGE CLUSTER OF MODERATE TO STRONG CONVECTION IS WITHIN 180 NM W OF THE AXIS FROM 06N TO 12N...AND CONVECTION IS ALSO ENHANCED ALONG THE WAVE AXIS IN THE GULF OF TEHUANTEPEC. ...THE ITCZ... THE ITCZ AXIS IS ALONG 08N77W TO 08N92W TO 09N114W TO 13N126W TO 10N137W TO 11N140W. ISOLATED MODERATE AND STRONG CONVECTION IS NOTED WITHIN 30 NM EITHER SIDE OF LINE 05N77W TO 08N88W TO 13N92W. AS MENTIONED SCATTERED MODERATE TO STRONG FROM 07N TO 11N BETWEEN 96N AND 98W ASSOCIATED WITH A TROPICAL WAVE. ALTHOUGH BROKEN LOW TO LOCALLY OVERCAST LOW CLOUDS COVER THE AREA FROM 04N TO 12N W OF 101W...ONLY A FEW TSTMS ARE NOTED WITHIN THE AREA FROM 06N TO 11N BETWEEN 101W AND 114W. ...DISCUSSION... AN UPPER CYCLONE IS NEAR 33N126W WITH AN UPPER TROUGH SW ALONG 30N127W TO 24N136W TO A BASE AT 11N133W. THE UPPER AIR IS DRY WITHIN ABOUT 120 NM OF THIS TROUGH AXIS. AN UPPER ANTICYCLONE IS AT 22N116W WITH A RIDGE EXTENDING W OVER HURRICANE LINDA AND A RIDGE EXTENDS E TO A SHARP CREST OVER CENTRAL OLD MEXICO AT 21N100W. DEBRIS MOISTURE FROM FORMER ITCZ CONVECTION BETWEEN 120W AND 130W IS ADVECTED N MERGING WITH THE DEBRIS MOISTURE FROM LINDAS CONVECTION...WITH THE RESULTANT PLUME NOW CROSSING THE BAJA PENINSULA. ANOTHER ARE OF UPPER MOISTURE IS NOTED S OF THE UPPER RIDGE...FROM 04N TO 15N BETWEEN 100W AND 120W. AN UPPER TROUGH EXTENDS SW ACROSS THE W CARIBBEAN AND OVER THE TROPICAL PACIFIC ALONG 14N83W TO 06N87W. UPPER DRY AIR IS NOTED BOTH SIDES OF THE THIS TROUGH BETWEEN 84W AND 94W AND SUPPRESSING CONVECTION TO ISOLATED AT BEST. UPPER DIFFLUENCE OVER THE DISCUSSION AREA E OF THIS TROUGH IS BEGINNING TO ENHANCE CONVECTION ALONG THE ITCZ...WITH THE DEBRIS MOISTURE ADVECTED NE ACROSS THE SW AND S CENTRAL CARIBBEAN. HURRICANE LINDA IS MOVING INTO A SURFACE RIDGE RESULTING IN WEAK NW TO SE RIDGING BOTH SW AND THE NE OF THE HURRICANE. THE PRESSURE GRADIENT BETWEEN LINDA AND THE SW RIDGE IS PRODUCING AN AREA OF NE WINDS 20 KT AND SEAS TO 9 FT IN NE SWELL. LOOKING AHEAD...A COLD FRONT WILL CLIP THE NW PORTION OF THE AREA DURING THE WEEKEND. LARGE LONG PERIOD NW SWELLS OF ABOUT 16 SECONDS WILL PROPAGATE ACROSS THE NW PART OF THE AREA BUILDING SEAS TO 11 FT BY SAT MORNING. CROSS EQUATORIAL SLY WINDS OF 20 KT AND SWELLS GENERATED BY A BROAD FIELD OF SE WINDS 20 TO 30 KT S OF THE EQUATOR WILL CONTINUE TO AFFECT THE FAR SOUTHERN PORTION MAINLY S OF 05N AND E OF 100W. $$ NELSON