359 
 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