000
WTPZ44 KNHC 211439
TCDEP4
 
HURRICANE DORA DISCUSSION NUMBER  13
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042011
800 AM PDT THU JUL 21 2011
 
SATELLITE IMAGES INDICATE THAT CONVECTION IN THE EYEWALL OF DORA HAS
BECOME MORE INTENSE DURING THE LAST SEVERAL HOURS...WITH THE EYE
STAYING MOSTLY CLEAR. VISIBLE PICTURES ARE RATHER SPECTACULAR WITH
MESOVORTICES NOTED WITHIN THE DISTINCT EYE. DVORAK ESTIMATES ARE
BETWEEN 127-140 KT...AND THE INITIAL INTENSITY IS SET TO 135 KT.
DORA IS EXPECTED TO BEGIN A DECLINE IN STRENGTH LATER TODAY AS IT
BEGINS TO MOVE INTO A BIT COOLER WATERS.  THE WEAKENING SHOULD
BECOME RATHER RAPID BY LATE TOMORROW DUE TO MUCH COLDER WATERS AND
SOME MODERATE NORTHEASTERLY SHEAR.  THE INTENSITY FORECAST IS A
BLEND OF THE INTENSITY GUIDANCE...AND IS CLOSEST TO THE LGEM MODEL.
 
THE LATEST MOTION ESTIMATE IS 310/11.  DORA SHOULD MOVE GENERALLY
TOWARD THE NORTHWEST AT A SLIGHTLY LOWER FORWARD SPEED DURING THE
NEXT COUPLE OF DAYS DUE TO RIDGING OVER NORTHERN MEXICO.  THE
GLOBAL MODELS ARE HAVING A DIFFICULT TIME RESOLVING THE RIDGE
STRENGTH AFTER THAT TIME...AND CONSEQUENTLY THERE IS SOME
DISAGREEMENT ON WHETHER THE NORTHWESTWARD TRACK CONTINUES OR DORA
BENDS TO THE WEST-NORTHWEST.  THE GUIDANCE HAS MADE ANOTHER SMALL
SHIFT TO THE RIGHT IN THE LONGER-RANGE...THOUGH EVERY RELIABLE
MODEL STILL KEEPS THE CORE OF THE HURRICANE WELL AWAY FROM BAJA
CALIFORNIA.  THE NHC FORECAST IS VIRTUALLY UNCHANGED THROUGH 48
HOURS...AND IS A BIT TO THE RIGHT OF THE PREVIOUS ONE AFTER THAT
TIME.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 17.1N 106.9W  135 KT 155 MPH
 12H  22/0000Z 18.1N 108.0W  130 KT 150 MPH
 24H  22/1200Z 19.1N 109.2W  115 KT 135 MPH
 36H  23/0000Z 20.0N 110.4W   90 KT 105 MPH
 48H  23/1200Z 20.8N 111.5W   75 KT  85 MPH
 72H  24/1200Z 22.5N 114.5W   45 KT  50 MPH
 96H  25/1200Z 24.4N 117.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  26/1200Z 26.0N 120.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BLAKE