000 WTPZ44 KNHC 200242 TCDEP4 HURRICANE DORA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042011 800 PM PDT TUE JUL 19 2011 SINCE THE PREVIOUS ADVISORY...A RAGGED EYE BECAME APPARENT IN INFRARED AND LATE-AFTERNOON VISIBLE SATELLITE IMAGERY. RECENT AMSR-E AND SSMIS MICROWAVE IMAGES ALSO SHOWED A BROKEN EYEWALL THAT APPEARS TO BE CONTRACTING. SUBJECTIVE DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB INCREASED TO 65 KT. THEREFORE...DORA IS UPGRADED TO A 65-KT HURRICANE...THE FOURTH OF THE 2011 EASTERN PACIFIC HURRICANE SEASON. THE HURRICANE SHOULD CONTINUE TO STRENGTHEN DURING THE NEXT COUPLE OF DAYS AS IT TRAVERSES WARM WATER AND REMAINS IN A LOW-SHEAR ENVIRONMENT. AS MENTIONED IN THE PREVIOUS NHC DISCUSSION...RAPID INTENSIFICATION IS CERTAINLY POSSIBLE...AND THE SHIPS RI INDEX IS SHOWING ABOUT A 1 IN 3 CHANCE OF A 30 KT INCREASE IN INTENSITY DURING THE NEXT 24 HOURS. THE NHC FORECAST IS ONCE AGAIN AT THE UPPER END OF THE GUIDANCE. RAPID WEAKENING IS ANTICIPATED AFTER 72 HOURS...AS DORA SHOULD BE MOVING OVER COOLER WATER AND INTO A MORE STABLE ENVIRONMENT. DORA CONTINUES TO MOVE STEADILY WEST-NORTHWEST TO THE SOUTH OF THE LARGE HIGH PRESSURE RIDGE OVER THE CENTRAL UNITED STATES. AS THE RIDGE WEAKENS AND MOVES EASTWARD IN 24-36 HOURS...THE HURRICANE SHOULD BEGIN TO SLOW DOWN AND TURN NORTHWESTWARD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT DURING THIS PERIOD. AFTER 48 HOURS...THE SPREAD OF THE TRACK GUIDANCE INCREASES WITH SEVERAL MODELS SHOWING A POTENTIAL THREAT TO BAJA CALIFORNIA. THE MOST RECENT RUNS OF THE GFS...HWRF...AND GFDL MODELS HAVE ALL SHIFTED EASTWARD IN THE LONGER RANGE. IN RESPONSE...THE NEW NHC TRACK HAS ALSO BEEN ADJUSTED EASTWARD...BUT IT REMAINS A LITTLE LEFT OF THE MULTI-MODEL CONSENSUS. THE CHANCES OF TROPICAL-STORM-FORCE WINDS HAVE INCREASED ALONG PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO PRIMARILY DUE TO THE EASTWARD SHIFT IN THE OFFICIAL TRACK FORECAST. THEREFORE...THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WATCH FROM LAZARO CARDENAS TO CABO CORRIENTES. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 13.4N 99.9W 65 KT 75 MPH 12H 20/1200Z 14.4N 101.9W 80 KT 90 MPH 24H 21/0000Z 15.7N 104.1W 90 KT 105 MPH 36H 21/1200Z 16.8N 105.8W 100 KT 115 MPH 48H 22/0000Z 17.9N 107.2W 110 KT 125 MPH 72H 23/0000Z 20.0N 109.5W 90 KT 105 MPH 96H 24/0000Z 22.0N 112.0W 60 KT 70 MPH 120H 25/0000Z 23.5N 115.5W 30 KT 35 MPH $$ FORECASTER BROWN 000 WTPZ44 KNHC 200242 TCDEP4 HURRICANE DORA DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042011 800 PM PDT TUE JUL 19 2011 SINCE THE PREVIOUS ADVISORY...A RAGGED EYE BECAME APPARENT IN INFRARED AND LATE-AFTERNOON VISIBLE SATELLITE IMAGERY. RECENT AMSR-E AND SSMIS MICROWAVE IMAGES ALSO SHOWED A BROKEN EYEWALL THAT APPEARS TO BE CONTRACTING. SUBJECTIVE DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB INCREASED TO 65 KT. THEREFORE...DORA IS UPGRADED TO A 65-KT HURRICANE...THE FOURTH OF THE 2011 EASTERN PACIFIC HURRICANE SEASON. THE HURRICANE SHOULD CONTINUE TO STRENGTHEN DURING THE NEXT COUPLE OF DAYS AS IT TRAVERSES WARM WATER AND REMAINS IN A LOW-SHEAR ENVIRONMENT. AS MENTIONED IN THE PREVIOUS NHC DISCUSSION...RAPID INTENSIFICATION IS CERTAINLY POSSIBLE...AND THE SHIPS RI INDEX IS SHOWING ABOUT A 1 IN 3 CHANCE OF A 30 KT INCREASE IN INTENSITY DURING THE NEXT 24 HOURS. THE NHC FORECAST IS ONCE AGAIN AT THE UPPER END OF THE GUIDANCE. RAPID WEAKENING IS ANTICIPATED AFTER 72 HOURS...AS DORA SHOULD BE MOVING OVER COOLER WATER AND INTO A MORE STABLE ENVIRONMENT. DORA CONTINUES TO MOVE STEADILY WEST-NORTHWEST TO THE SOUTH OF THE LARGE HIGH PRESSURE RIDGE OVER THE CENTRAL UNITED STATES. AS THE RIDGE WEAKENS AND MOVES EASTWARD IN 24-36 HOURS...THE HURRICANE SHOULD BEGIN TO SLOW DOWN AND TURN NORTHWESTWARD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT DURING THIS PERIOD. AFTER 48 HOURS...THE SPREAD OF THE TRACK GUIDANCE INCREASES WITH SEVERAL MODELS SHOWING A POTENTIAL THREAT TO BAJA CALIFORNIA. THE MOST RECENT RUNS OF THE GFS...HWRF...AND GFDL MODELS HAVE ALL SHIFTED EASTWARD IN THE LONGER RANGE. IN RESPONSE...THE NEW NHC TRACK HAS ALSO BEEN ADJUSTED EASTWARD...BUT IT REMAINS A LITTLE LEFT OF THE MULTI-MODEL CONSENSUS. THE CHANCES OF TROPICAL-STORM-FORCE WINDS HAVE INCREASED ALONG PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO PRIMARILY DUE TO THE EASTWARD SHIFT IN THE OFFICIAL TRACK FORECAST. THEREFORE...THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WATCH FROM LAZARO CARDENAS TO CABO CORRIENTES. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 13.4N 99.9W 65 KT 75 MPH 12H 20/1200Z 14.4N 101.9W 80 KT 90 MPH 24H 21/0000Z 15.7N 104.1W 90 KT 105 MPH 36H 21/1200Z 16.8N 105.8W 100 KT 115 MPH 48H 22/0000Z 17.9N 107.2W 110 KT 125 MPH 72H 23/0000Z 20.0N 109.5W 90 KT 105 MPH 96H 24/0000Z 22.0N 112.0W 60 KT 70 MPH 120H 25/0000Z 23.5N 115.5W 30 KT 35 MPH $$ FORECASTER BROWN