000 WTPZ44 KNHC 120838 TCDEP4 HURRICANE CARLOS DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042009 200 AM PDT SUN JUL 12 2009 SATELLITE IMAGERY SUGGESTS THAT CARLOS MAY HAVE ENTERED A PERIOD OF ARRESTED DEVELOPMENT DURING THE PAST FEW HOURS...AS THE INTERMITTENT EYE FEATURE HAS DISAPPEARED AND AN ASYMMETRY IS NOTED WITHIN THE CENTRAL CONVECTION. AS A RESULT...DVORAK T-NUMBERS HAVE LEVELED OFF...WITH ESTIMATES OF 4.0 AND 4.5 FROM SAB AND TAFB... RESPECTIVELY. GIVEN CURRENT TRENDS AND SATELLITE ESTIMATES...THE INTENSITY IS MAINTAINED AT 75 KT. CARLOS SHOULD ENCOUNTER WEAK ENVIRONMENTAL SHEAR AND WARM SEA SURFACE TEMPERATURES ALONG THE FORECAST TRACK DURING THE NEXT 2 TO 3 DAYS...WHICH SHOULD FAVOR ADDITIONAL STRENGTHENING. HOWEVER... THE SHIPS MODEL GUIDANCE NO LONGER INDICATES THAT CARLOS WILL BECOME A MAJOR HURRICANE AS A CONSEQUENCE OF MORE MARGINAL THERMODYNAMIC PARAMETERS. IN ADDITION...THE SHIPS RAPID INTENSIFICATION INDEX IS NOT AS EMPHATIC AS IT WAS PREVIOUSLY. THE OFFICIAL FORECAST IS ONLY A LITTLE LESS BULLISH THAN THE PREVIOUS ONE AND STILL BRINGS CARLOS TO MAJOR HURRICANE STATUS IN 36 TO 48 HR. THIS IS ALSO A COMPROMISE BETWEEN THE LATEST HWRF AND GFDL HURRICANE MODEL WIND SPEED FORECASTS...WITH THE FORMER MODEL BEING SIGNIFICANTLY MORE AGGRESSIVE. THEREAFTER...THE COMBINATION OF INCREASING WESTERLY FLOW ALOFT AND COOLER WATERS SHOULD RESULT IN GRADUAL WEAKENING. THE INITIAL MOTION IS ESTIMATED AT 270/11. A DOMINANT MID- TO UPPER-LEVEL SUBTROPICAL RIDGE NORTH OF THE CYCLONE SHOULD KEEP CARLOS ON A GENERAL WESTWARD COURSE OVER THE NEXT FEW DAYS...WITH SOME SUBTLE INCREASE IN LATITUDE TOWARD THE END OF THE FORECAST PERIOD. MODELS CONTINUE TO DISAGREE...HOWEVER...ON THE PREDICTED FORWARD SPEED OF CARLOS BEYOND 96 HR...WITH THE GFDL AND HWRF NOTABLY FASTER THAN THE UKMET AND ECMWF. THE OFFICIAL TRACK IS CLOSE TO THE PREVIOUS NHC TRACK AND ALSO TO THE TO THE DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 12/0900Z 10.5N 120.0W 75 KT 12HR VT 12/1800Z 10.6N 121.8W 85 KT 24HR VT 13/0600Z 10.8N 124.1W 95 KT 36HR VT 13/1800Z 11.1N 126.6W 100 KT 48HR VT 14/0600Z 11.4N 128.8W 100 KT 72HR VT 15/0600Z 12.2N 133.4W 95 KT 96HR VT 16/0600Z 13.0N 138.0W 85 KT 120HR VT 17/0600Z 14.0N 142.5W 75 KT $$ FORECASTER KIMBERLAIN/PASCH