Hurricane DORA

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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
 
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