000 WTPZ44 KNHC 190839 TCDEP4 TROPICAL STORM DORA DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042011 200 AM PDT TUE JUL 19 2011 SATELLITE IMAGES SHOW THAT DEEP CONVECTION HAS INCREASED NEAR THE CENTER OF DORA DURING THE LAST SEVERAL HOURS. IN ADDITION...A SSMIS PASS AT 0242 UTC SUGGESTS THAT THE INNER-CORE HAS BECOME A LITTLE BETTER DEFINED. THE INITIAL WIND SPEED IS SET TO 55 KT BASED ON A DVORAK CI-NUMBER OF 3.5 FROM TAFB AND UW-CIMSS ADT ESTIMATES OF 50 TO 55 KT. DORA IS MOVING WESTWARD AT 14 KT ON THE SOUTH SIDE OF A LARGE AND POTENT MID- TO UPPER-LEVEL HIGH LOCATED OVER THE CENTRAL UNITED STATES. THE TROPICAL CYCLONE IS EXPECTED TO GENERALLY TRACK WEST-NORTHWESTWARD AT ABOUT THE SAME SPEED FOR THE NEXT 24 TO 36 HOURS AS THE HIGH SLOWLY WEAKENS. BEYOND 36 HOURS...A WEST-NORTHWESTWARD TO NORTHWESTWARD MOTION AND A DECREASE IN FORWARD SPEED ARE FORECAST AS A DEEP-LAYER TROUGH OVER THE WESTERN UNITED STATES PUSHES THE RIDGE EASTWARD. THE TRACK MODEL GUIDANCE IS SIMILAR TO THE PREVIOUS CYCLE AND THE OFFICIAL FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS PACKAGE...KEEPING THE CENTER OF DORA OFFSHORE OF MEXICO. ADDITIONAL INTENSIFICATION OF DORA APPEARS LIKELY DURING THE NEXT COUPLE OF DAYS AS THE CYCLONE REMAINS OVER SEA SURFACE TEMPERATURES AROUND 29C AND IN A MOIST ATMOSPHERIC ENVIRONMENT. IN ADDITION... THE MODERATE NORTHERLY WIND SHEAR CURRENTLY AFFECTING THE STORM IS EXPECTED TO LESSEN. THE OFFICIAL FORECAST BRINGS DORA TO HURRICANE STRENGTH LATER TODAY AND TO MAJOR HURRICANE STATUS IN ABOUT 2 DAYS. THE NHC FORECAST IS IN BEST AGREEMENT WITH THE GFDL MODEL AND THE FLORIDA STATE SUPERENSEMBLE FOR THE FIRST 2 TO 3 DAYS. STEADY OR EVEN RAPID WEAKENING IS EXPECTED TO COMMENCE IN 3 TO 4 DAYS AS DORA MOVES OVER MUCH COOLER WATERS AND INTO A MORE STABLE ATMOSPHERIC ENVIRONMENT. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 11.4N 95.9W 55 KT 65 MPH 12H 19/1800Z 12.1N 98.1W 65 KT 75 MPH 24H 20/0600Z 13.3N 100.8W 75 KT 85 MPH 36H 20/1800Z 14.5N 103.2W 90 KT 105 MPH 48H 21/0600Z 15.7N 105.4W 105 KT 120 MPH 72H 22/0600Z 17.8N 108.5W 100 KT 115 MPH 96H 23/0600Z 19.5N 110.5W 75 KT 85 MPH 120H 24/0600Z 21.5N 113.5W 50 KT 60 MPH $$ FORECASTER CANGIALOSI 000 WTPZ44 KNHC 190839 TCDEP4 TROPICAL STORM DORA DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042011 200 AM PDT TUE JUL 19 2011 SATELLITE IMAGES SHOW THAT DEEP CONVECTION HAS INCREASED NEAR THE CENTER OF DORA DURING THE LAST SEVERAL HOURS. IN ADDITION...A SSMIS PASS AT 0242 UTC SUGGESTS THAT THE INNER-CORE HAS BECOME A LITTLE BETTER DEFINED. THE INITIAL WIND SPEED IS SET TO 55 KT BASED ON A DVORAK CI-NUMBER OF 3.5 FROM TAFB AND UW-CIMSS ADT ESTIMATES OF 50 TO 55 KT. DORA IS MOVING WESTWARD AT 14 KT ON THE SOUTH SIDE OF A LARGE AND POTENT MID- TO UPPER-LEVEL HIGH LOCATED OVER THE CENTRAL UNITED STATES. THE TROPICAL CYCLONE IS EXPECTED TO GENERALLY TRACK WEST-NORTHWESTWARD AT ABOUT THE SAME SPEED FOR THE NEXT 24 TO 36 HOURS AS THE HIGH SLOWLY WEAKENS. BEYOND 36 HOURS...A WEST-NORTHWESTWARD TO NORTHWESTWARD MOTION AND A DECREASE IN FORWARD SPEED ARE FORECAST AS A DEEP-LAYER TROUGH OVER THE WESTERN UNITED STATES PUSHES THE RIDGE EASTWARD. THE TRACK MODEL GUIDANCE IS SIMILAR TO THE PREVIOUS CYCLE AND THE OFFICIAL FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS PACKAGE...KEEPING THE CENTER OF DORA OFFSHORE OF MEXICO. ADDITIONAL INTENSIFICATION OF DORA APPEARS LIKELY DURING THE NEXT COUPLE OF DAYS AS THE CYCLONE REMAINS OVER SEA SURFACE TEMPERATURES AROUND 29C AND IN A MOIST ATMOSPHERIC ENVIRONMENT. IN ADDITION... THE MODERATE NORTHERLY WIND SHEAR CURRENTLY AFFECTING THE STORM IS EXPECTED TO LESSEN. THE OFFICIAL FORECAST BRINGS DORA TO HURRICANE STRENGTH LATER TODAY AND TO MAJOR HURRICANE STATUS IN ABOUT 2 DAYS. THE NHC FORECAST IS IN BEST AGREEMENT WITH THE GFDL MODEL AND THE FLORIDA STATE SUPERENSEMBLE FOR THE FIRST 2 TO 3 DAYS. STEADY OR EVEN RAPID WEAKENING IS EXPECTED TO COMMENCE IN 3 TO 4 DAYS AS DORA MOVES OVER MUCH COOLER WATERS AND INTO A MORE STABLE ATMOSPHERIC ENVIRONMENT. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 11.4N 95.9W 55 KT 65 MPH 12H 19/1800Z 12.1N 98.1W 65 KT 75 MPH 24H 20/0600Z 13.3N 100.8W 75 KT 85 MPH 36H 20/1800Z 14.5N 103.2W 90 KT 105 MPH 48H 21/0600Z 15.7N 105.4W 105 KT 120 MPH 72H 22/0600Z 17.8N 108.5W 100 KT 115 MPH 96H 23/0600Z 19.5N 110.5W 75 KT 85 MPH 120H 24/0600Z 21.5N 113.5W 50 KT 60 MPH $$ FORECASTER CANGIALOSI