000 WTPZ45 KNHC 110238 TCDEP5 TROPICAL STORM LINDA DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152009 800 PM PDT THU SEP 10 2009 LINDA APPEARS TO BE WEAKENING QUICKLY AS IT MOVES OVER SUB 26C WATERS AND ENCOUNTERS AROUND 20 KNOTS OF SOUTHERLY TO SOUTHWESTERLY WIND SHEAR AS ANALYZED BY UW-CIMSS AND THE SHIPS MODEL. SATELLITE IMAGERY SHOWS A THINNING OF THE CONVECTIVE OVERCAST AND WARMING CLOUD TOPS OVER THE PAST FEW HOURS. A 2010 UTC TRMM PASS AND A 2140 UTC AMSR-E PASS SHOW CONTINUED VERTICAL DECOUPLING OF THE CYCLONE...WITH THE LOW-LEVEL CENTER LOCATED ABOUT A HALF A DEGREE SOUTHEAST OF THE MID-LEVEL CENTER. THE CURRENT INTENSITY ESTIMATE IS 55 KT...A LITTLE LOWER THAN A BLEND OF DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB AND 3-HOUR AVERAGE ADT T-NUMBERS DUE TO THE DEGRADED SATELLITE PRESENTATION OF THE SYSTEM. LINDA WILL BE MOVING OVER SSTS LESS THAN 24C AFTER 24 HOURS...WHICH IN COMBINATION WITH CONTINUED STRONG SOUTHWESTERLY SHEAR SHOULD RESULT IN STEADY WEAKENING TO A REMNANT LOW IN ABOUT 48 HOURS AND DISSIPATION IN 4 OR 5 DAYS. THIS REASONING IS REFLECTED IN THE OFFICIAL FORECAST...WHICH IS CLOSE TO THE ICON INTENSITY CONSENSUS. THE AFOREMENTIONED MICROWAVE IMAGERY SHOWED THAT THE LOW-LEVEL CENTER WAS LOCATED A LITTLE BEHIND PREVIOUS ESTIMATES. THE INITIAL MOTION ESTIMATE IS 330/07...AS LINDA IS BEING STEERED TOWARD THE NORTH-NORTHWEST BY A MID- TO UPPER-LEVEL LOW CENTERED NEAR 23N142W AND A MID- TO UPPER-LEVEL HIGH CENTERED NEAR 22N117W. AS LINDA BECOMES AN INCREASINGLY SHALLOW SYSTEM...IT WILL DECOUPLE FROM THE DEEP-LAYER FLOW AND BEGIN TO MOVE NORTHWESTWARD INTO A WEAKNESS IN THE LOW- TO MID-LEVEL SUBTROPICAL RIDGE BETWEEN 130W AND 135W. IF LINDA IS STILL AROUND NEAR THE END OF THE PERIOD...IT COULD BE PULLED NORTHWARD BY A DEEP-LAYER TROUGH APPROACHING THE CALIFORNIA COAST. ALTERNATIVELY...IT COULD TURN WESTWARD IF THAT TROUGH PASSES BY TO THE NORTH. THE NEW TRACK FORECAST IS SHIFTED A LITTLE TO THE LEFT OF THE PREVIOUS FORECAST... TOWARD THE TVCN MULTI-MODEL CONSENSUS...BEFORE SHOWING A VERY SLOW NORTHWESTWARD MOTION PRIOR TO DISSIPATION. FORECAST POSITIONS AND MAX WINDS INITIAL 11/0300Z 19.9N 130.5W 55 KT 12HR VT 11/1200Z 20.8N 131.0W 50 KT 24HR VT 12/0000Z 21.7N 131.8W 40 KT 36HR VT 12/1200Z 22.1N 132.3W 30 KT 48HR VT 13/0000Z 22.3N 132.7W 25 KT...REMNANT LOW 72HR VT 14/0000Z 22.5N 133.3W 20 KT...REMNANT LOW 96HR VT 15/0000Z 23.0N 133.5W 20 KT...REMNANT LOW 120HR VT 16/0000Z...DISSIPATED $$ FORECASTER BRENNAN