634 
 WTPZ44 KNHC 200853
 TCDEP4
  
 HURRICANE DORA DISCUSSION NUMBER   8
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042011
 200 AM PDT WED JUL 20 2011
  
 WHILE AN EYE HAS NOT BEEN APPARENT IN RECENT GEOSTATIONARY IMAGERY
 ...THERE HAS BEEN AN OVERALL INCREASE IN DEEP CONVECTION NEAR THE
 CENTER OF DORA IN THE PAST FEW HOURS.  THE INITIAL INTENSITY IS SET
 TO 70 KT FOR THIS ADVISORY BASED ON A BLEND OF DVORAK ESTIMATES OF
 77 KT FROM TAFB AND 65 KT FROM SAB AT 0600 UTC.  DORA WILL BE IN  
 AN ENVIRONMENT THAT IS VERY FAVORABLE FOR INTENSIFICATION OVER THE
 NEXT 36 TO 48 HOURS...WITH VERY WARM SSTS AND SHEAR OF AROUND 10 KT
 OR LESS.  AFTER THAT TIME...DORA WILL MOVE ACROSS A SHARP SST
 GRADIENT INTO COOLER WATERS AND A MORE STABLE ATMOSPHERE...WHICH
 SHOULD RESULT IN RAPID WEAKENING LATE IN THE PERIOD.  IN THE SHORT
 TERM THE OFFICIAL FORECAST LEANS TOWARD THE GFDL MODEL...AND SHOWS
 A PEAK INTENSITY OF 110 KT IN 36 HOURS.  AFTER THAT TIME...THE NHC
 FORECAST IS CLOSEST TO A BLEND OF THE SHIPS AND LGEM.
  
 THE INITIAL MOTION ESTIMATE IS TOWARD THE WEST-NORTHWEST AT 16 KNOTS
 ...AS DORA CONTINUES TO BE STEERED BY THE STRONG MID-LEVEL RIDGE
 CENTERED OVER THE CENTRAL UNITED STATES.  AS THE RIDGE WEAKENS AND
 MOVES EASTWARD OVER THE NEXT COUPLE OF DAYS...DORA WILL GRADUALLY
 SLOW DOWN AND TURN TOWARD THE NORTHWEST.  MUCH OF THE TRACK
 GUIDANCE FOR THIS CYCLE HAS SHIFTED BACK TO THE LEFT...INCLUDING
 THE GFS...GFDL....AND HWRF MODELS.  THE NEW OFFICIAL FORECAST HAS
 BEEN NUDGED TO THE LEFT AND LIES NEAR THE MULTI-MODEL CONSENSUS
 THROUGH 48 HOURS AND IS TO THE RIGHT OF THE CONSENSUS AFTER THAT
 TIME.  GIVEN THE LARGE CYCLE-TO-CYCLE VARIABILITY IN THE TRACK
 GUIDANCE AND THE EXTENT OF 34-KT WINDS NORTH OF THE CENTER...THE
 TROPICAL STORM WATCH REMAINS IN PLACE FOR PART OF THE COAST OF
 MAINLAND MEXICO.  BASED ON THE OFFICIAL FORECAST AND PAST NHC
 FORECAST ERRORS...THERE IS A 35 TO 40 PERCENT CHANCE OF TROPICAL
 STORM FORCE WINDS OCCURRING SOMEWHERE IN THE WATCH AREA.  DORA
 COULD ALSO THREATEN THE SOUTHERN BAJA CALIFORNIA PENINSULA IN 60 TO
 72 HOURS. 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  20/0900Z 14.1N 101.6W   70 KT  80 MPH
  12H  20/1800Z 15.1N 103.5W   85 KT 100 MPH
  24H  21/0600Z 16.4N 105.5W   95 KT 110 MPH
  36H  21/1800Z 17.5N 107.1W  110 KT 125 MPH
  48H  22/0600Z 18.6N 108.4W  105 KT 120 MPH
  72H  23/0600Z 20.5N 110.7W   85 KT 100 MPH
  96H  24/0600Z 22.5N 113.5W   55 KT  65 MPH
 120H  25/0600Z 24.0N 117.0W   30 KT  35 MPH
  
 $$
 FORECASTER BRENNAN