362 
 WTPZ44 KNHC 220850
 TCDEP4
  
 HURRICANE DORA DISCUSSION NUMBER  16
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042011
 200 AM PDT FRI JUL 22 2011
  
 STRONG VERTICAL SHEAR CONTINUES TO TAKE ITS TOLL ON HURRICANE DORA
 THIS MORNING.  WHAT WAS ONCE...JUST A FEW HOURS AGO...A WARM EYE
 SURROUNDED BY QUITE COLD CLOUD TOPS IS NOW A PARTIALLY EXPOSED
 LOW-LEVEL VORTEX WITH THE DEEP CONVECTION TO BE FOUND ONLY IN THE
 SOUTHERN SEMICIRCLE.  RAW DATA-T NUMBERS FROM TAFB...SAB...AND ADT
 HAVE ALL PLUMMETED.  ASSUMING THAT IT TAKES SOME LAG TIME FOR THE
 WINDS TO WEAKEN AS MUCH AS THE CONVECTIVE SIGNATURE...THE INTENSITY
 IS ANALYZED AT 90 KT...20 KT WEAKER THAN THE PREVIOUS ADVISORY.
  
 WHILE THE STRONG NORTHERLY VERTICAL SHEAR SHOULD DIMINISH OVER THE
 NEXT DAY...DORA WILL BE ENCOUNTERING AN INCREASINGLY HOSTILE
 THERMODYNAMIC ENVIRONMENT WITH COLD SSTS AND A STABLE ATMOSPHERE
 WITHIN THE NEXT 24 HOURS.  WITHIN ABOUT TWO DAYS...THE CYCLONE WILL
 BE TRAVERSING OVER 23C WATER AND MOVING THROUGH AN ATMOSPHERE THAT
 WILL LIKELY NOT ALLOW DEEP CONVECTION.  THE INTENSITY FORECAST IS
 CLOSE TO THE LGEM-SHIPS STATISTICAL INTENSITY MODELS...BUT
 SUBSTANTIALLY BELOW THAT OF THE PREVIOUS ADVISORY BECAUSE OF THE
 CONTINUED RAPID WEAKENING.
  
 THE HURRICANE IS MOVING NORTHWESTWARD AT 8 KT ALONG THE SOUTHWESTERN
 PERIPHERY OF A DEEP-LAYERED RIDGE.  THIS SAME FEATURE SHOULD
 CONTINUE STEERING DORA NORTHWESTWARD AT ABOUT THE SAME SPEED UNTIL
 DISSIPATION.  THE FORECAST TRACK IS BASED UPON A BLEND OF THE
 MULTI-MODEL CONSENSUS IS NEARLY THE SAME AS THE PREVIOUS ADVISORY.
  
 IN ADDITION TO THE WEAKENING...AMSU AND ASCAT SATELLITE PASSES
 INDICATE THAT DORA EXHIBITS A SUBSTANTIALLY SMALLER 34-KT WIND
 RADII THAN PREVIOUSLY ANALYZED.  THIS SUGGESTS A DIMINISHED RISK OF
 TROPICAL-STORM-FORCE WINDS FOR SOUTHERN BAJA CALIFORNIA AS SHOWN IN
 THE REDUCED WIND SPEED PROBABILITIES.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  22/0900Z 18.9N 108.8W   90 KT 105 MPH
  12H  22/1800Z 19.5N 109.5W   75 KT  85 MPH
  24H  23/0600Z 20.5N 110.6W   60 KT  70 MPH
  36H  23/1800Z 21.4N 111.7W   50 KT  60 MPH
  48H  24/0600Z 22.5N 113.0W   40 KT  45 MPH
  72H  25/0600Z 24.5N 116.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
  96H  26/0600Z 26.0N 117.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  27/0600Z 27.0N 118.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER LANDSEA/STEWART