000
WTPZ44 KNHC 210248
TCDEP4
 
HURRICANE DORA DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042011
800 PM PDT WED JUL 20 2011
 
DORA CONTINUED TO RAPIDLY STRENGTHEN THIS AFTERNOON.  SATELLITE
IMAGERY SHOWS VERY DEEP CONVECTION SURROUNDING A 25-30 N MI-WIDE
EYE THAT HAS WARMED AND BECOME MUCH BETTER DEFINED.  OBJECTIVE
DVORAK T-NUMBERS FROM UW-CIMSS HAVE NOW INCREASED TO T6.2.  THE
MOST RECENT SUBJECTIVE DVORAK T-NUMBERS OF T5.5 WERE A LITTLE LOWER
THAN THE OBJECTIVE NUMBERS...BECAUSE THE COLDEST RING OF CONVECTION
AROUND THE EYE ON THE 2345 UTC SATELLITE IMAGE HAD A FEW BREAKS.
BASED ON THE OBJECTIVE ESTIMATES THE INITIAL INTENSITY HAS BEEN
INCREASED TO 115 KT.
 
DORA HAS TIME FOR SOME ADDITIONAL STRENGTHENING AS IT WILL REMAIN
OVER 28-29 DEGREE CELSIUS SSTS AND IN A LOW SHEAR ENVIRONMENT FOR
ANOTHER 24 HOURS.  THE NHC INTENSITY FORECAST IS NEAR THE UPPER END
OF THE GUIDANCE AND CALLS FOR PEAK INTENSITY OF 125 KT.  WEAKENING
SHOULD BEGIN BETWEEN 24 AND 36 HOURS AS THE HURRICANE MOVES OVER
DECREASING SSTS.  A MUCH FASTER RATE OF WEAKENING IS EXPECTED AFTER
TWO DAYS AS DORA EXPLORES THE COLDER WATERS OF THE EASTERN
PACIFIC.
 
THE INITIAL MOTION ESTIMATE IS 295/14.  A TURN TOWARD THE NORTHWEST
WITH A REDUCTION IN FORWARD SPEED SHOULD OCCUR VERY SOON AS THE
RIDGE OVER THE CENTRAL UNITED STATES SHIFTS EASTWARD AND WEAKENS.
THEREAFTER...DORA IS FORECAST TO MAINTAIN A HEADING BETWEEN
NORTHWEST AND WEST-NORTHWEST UNTIL IT BECOMES A POST-TROPICAL
REMNANT LOW IN ABOUT 5 DAYS.  THE TRACK GUIDANCE CONTINUES TO HAVE
SOME CONSISTENCY ISSUES WITH NOTABLE EAST-WEST SHIFTS OCCURRING
FROM RUN TO RUN DURING THE PAST DAY OR SO.  THE LATEST GUIDANCE
SHIFTED BACK EASTWARD...BUT FOR NOW THE NHC FORECAST WILL MAINTAIN
CONTINUITY WITH THE PREVIOUS FORECAST AND IS IN BEST AGREEMENT
WITHIN THE ECMWF.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/0300Z 16.0N 105.4W  115 KT 135 MPH
 12H  21/1200Z 17.0N 106.7W  125 KT 145 MPH
 24H  22/0000Z 18.2N 108.2W  125 KT 145 MPH
 36H  22/1200Z 19.1N 109.4W  110 KT 125 MPH
 48H  23/0000Z 19.9N 110.6W   90 KT 105 MPH
 72H  24/0000Z 21.5N 113.5W   60 KT  70 MPH
 96H  25/0000Z 23.0N 117.0W   30 KT  35 MPH
120H  26/0000Z 25.0N 120.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BROWN