000 WTPZ44 KNHC 132038 TCDEP4 TROPICAL STORM PATRICIA DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP192009 200 PM PDT TUE OCT 13 2009 QUIKSCAT DATA NEAR 13Z SHOWED A 45-50 KT WIND VECTOR ABOUT 45 N MI SOUTH OF THE CENTER OF PATRICIA. SINCE THAT TIME...THE ASSOCIATED CONVECTION HAS DISSIPATED...LEAVING A SWIRL OF LOW CLOUDS PARTLY OBSCURED BY CIRRUS DEBRIS. THE INITIAL INTENSITY IS REDUCED TO 45 KT BASED ON A SLOW DECAY FROM THE TIME OF THE QUIKSCAT DATA...AND THIS INTENSITY COULD BE GENEROUS. WHY THE CONVECTION HAS DECREASED IS NOT CLEAR...BUT UPPER-LEVEL CONFLUENCE AND ENTRAINMENT OF DRY AND STABLE AIR INTO THE CYCLONE FROM THE WEST COULD BE REASONS. THE INITIAL MOTION REMAINS JUST EAST OF NORTH AT 010/6. ALL OF THE DYNAMICAL MODELS NOW FORECAST ENOUGH MID-LEVEL RIDGING DEVELOPING NORTH OF PATRICIA TO TURN THE CYCLONE WESTWARD IN THE NEXT 12-24 HRS...AND THERE IS SOME INDICATION OF THE RIDGE BUILDING IN WATER VAPOR IMAGERY. THE CANADIAN AND ECMWF MODELS BRING THE CENTER OVER THE SOUTHERN END OF BAJA CALIFORNIA BEFORE THE TURN OCCURS...AND WITH THE CURRENT MOTION THIS CANNOT BE RULED OUT. THE NEW FORECAST TRACK IS NUDGED A LITTLE TO THE NORTH OF THE PREVIOUS TRACK BASED ON THE CURRENT POSITION AND MOTION...CALLING FOR THE CENTER TO TURN NORTHWESTWARD AND PASS JUST SOUTH OF THE CABO SAN LUCAS AREA IN ABOUT 12 HRS. AFTER THAT...THE SYSTEM SHOULD MOVE GENERALLY WESTWARD UNTIL IT DISSIPATES. THE NEW TRACK IS JUST NORTH OF THE CENTER OF THE GUIDANCE ENVELOPE. PATRICIA REMAINS IN A LIGHT VERTICAL WIND SHEAR ENVIRONMENT OVER WARM WATER. THUS...THERE IS STILL THE POSSIBILITY OF A CONVECTIVE FLARE-UP LATER TONIGHT THAT COULD MAINTAIN THE INTENSITY OF THE STORM. AFTER 12-24 HRS...THE SYSTEM WILL BE MOVING OVER COOLER SEA SURFACE TEMPERATURES AND INTO THE DRY AIR MASS WEST OF BAJA CALIFORNIA. THIS COMBINATION SHOULD CAUSE PATRICIA TO WEAKEN. THE NEW INTENSITY FORECAST IS A SIGNIFICANT CHANGE FROM THE PREVIOUS FORECAST BASED ON CURRENT TRENDS AND THE STATISTICAL GUIDANCE...CALLING FOR PATRICIA TO SLOWLY WEAKEN THROUGH THE FORECAST PERIOD. THE GLOBAL MODELS ALL SHOW PATRICIA DISSIPATING IN 60 HRS OR LESS...SO IF THE CONVECTION DOES NOT COME BACK THE CYCLONE COULD DISSIPATE EARLIER THAN CURRENTLY FORECAST. THE WIND RADII HAVE BEEN REVISED BASED ON THE QUIKSCAT DATA. FORECAST POSITIONS AND MAX WINDS INITIAL 13/2100Z 22.1N 108.9W 45 KT 12HR VT 14/0600Z 22.7N 109.4W 40 KT 24HR VT 14/1800Z 22.7N 110.6W 35 KT 36HR VT 15/0600Z 22.8N 112.2W 30 KT 48HR VT 15/1800Z 22.9N 114.0W 30 KT 72HR VT 16/1800Z 23.0N 117.5W 25 KT...REMNANT LOW 96HR VT 17/1800Z 23.0N 121.0W 20 KT...REMNANT LOW 120HR VT 18/1800Z...DISSIPATED $$ FORECASTER BEVEN