000 WTPZ45 KNHC 160232 TCDEP5 TROPICAL STORM DOLORES DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP052009 800 PM PDT WED JUL 15 2009 VISIBLE SATELLITE IMAGERY SUGGESTS THAT THE CIRCULATION OF DOLORES IS SOMEWHAT ELONGATED FROM NORTHWEST TO SOUTHEAST. IN ADDITION... CONVECTION HAS BEEN ROTATING CYCLONICALLY FROM THE NORTH SIDE OF DOLORES TO ITS CURRENT LOCATION IN THE WESTERN SEMICIRCLE. HOWEVER...CONVECTION IS NOW CLOSER TO THE CENTER OF THE STORM...THE OUTFLOW IS EXPANDING WESTWARD...AND OVERALL DOLORES IS DISPLAYING A HEALTHIER SATELLITE SIGNATURE THAN EARLIER TODAY. SATELLITE CLASSIFICATIONS FROM SAB/TAFB/CIMSS ARE ALL 45 KT...AND THE INITIAL INTENSITY WILL BE RAISED TO THAT VALUE. THERE IS A SHORT WINDOW AVAILABLE FOR ANY FURTHER INTENSIFICATION SINCE THE STORM WILL BE OVER SSTS LESS THAN 26C BY TOMORROW AFTERNOON. AFTER THAT TIME...A SLOW WEAKENING IS LIKELY AS DOLORES MOVES OVER PROGRESSIVELY COOLER WATERS. THE WEAKENING COULD BE PROTRACTED DUE TO GENERALLY LIGHT FORECAST ENVIRONMENTAL SHEAR FOR THE NEXT FEW DAYS. GLOBAL MODELS FORECAST A SIGNIFICANT INCREASE IN SHEAR IN ABOUT 2 TO 3 DAYS... WHICH SHOULD CONTRIBUTE TO A TRANSITION OF THE SYSTEM TO A REMNANT LOW AROUND THAT TIME. THE INITIAL MOTION IS ESTIMATED AT ABOUT 310/12. THERE IS NO CHANGE TO THE SHORT-TERM SYNOPTIC REASONING AS DOLORES IS BEING STEERED PRIMARILY BY A LARGE HIGH CENTERED OVER THE SOUTHWESTERN UNITED STATES. THIS HIGH IS FORECAST TO STRENGTHEN AND SHIFT WESTWARD OVER THE NEXT COUPLE OF DAYS...WHICH COULD GRADUALLY FORCE THE STORM ON MORE OF A WEST-NORTHWEST PATH DURING THE NEXT DAY OR SO. HOWEVER...SOME MODELS...SUCH AS THE GFS/ECMWF/NOGAPS...ARE NOW FORECASTING A WEAKER RIDGE AND LESS OF A WEST-NORTHWEST TURN. THE OFFICIAL FORECAST IS SHIFTED TO THE NORTH OF THE PREVIOUS TRACK BUT STILL LIES SOUTH OF THE MODEL CONSENSUS...NOT TOO FAR FROM THE GFDL/HWRF. AT LONGER RANGES...MOST OF THE MODELS NOW SUGGEST A DEEP-LAYER WEAKNESS IN THE SUBTROPICAL RIDGE NEAR 140W...WHICH COULD ALLOW A CONTINUED WEST-NORTHWEST MOTION. THE NHC FORECAST HAS BEEN SHIFTED CONSIDERABLY NORTHEASTWARD BY 120 HR...BUT IS STILL ON THE FAR SOUTHWESTERN EDGE OF THE GUIDANCE ENVELOPE AT THAT TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 16/0300Z 17.1N 117.4W 45 KT 12HR VT 16/1200Z 18.2N 119.5W 50 KT 24HR VT 17/0000Z 19.4N 122.4W 45 KT 36HR VT 17/1200Z 20.6N 125.3W 40 KT 48HR VT 18/0000Z 21.5N 128.2W 35 KT 72HR VT 19/0000Z 23.0N 133.5W 25 KT...REMNANT LOW 96HR VT 20/0000Z 24.0N 139.0W 20 KT...REMNANT LOW 120HR VT 21/0000Z 25.5N 143.5W 20 KT...REMNANT LOW $$ FORECASTER BLAKE