000
WTPZ44 KNHC 221431
TCDEP4
 
HURRICANE DORA DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP042011
800 AM PDT FRI JUL 22 2011
 
DORA CONTINUES TO WEAKEN.  WHILE CONVECTION HAS REDEVELOPED NEAR THE
CENTER...THE SATELLITE SIGNATURE IS NOT VERY IMPRESSIVE WITH ALMOST
OF THE CONVECTION IN THE SOUTHEASTERN PORTION OF THE CYCLONE.
SATELLITE INTENSITY ESTIMATES ARE 77-82 KT FROM SUBJECTIVE AND
OBJECTIVE DVORAK TECHNIQUES...THOUGH THE DATA T-NUMBERS ARE QUITE A
BIT LOWER.  THE WIND SPEED IS REDUCED TO 75 KT FOR THIS ADVISORY.
A NOAA RESEARCH AIRCRAFT IS SCHEDULED TO CONDUCT A RESEARCH MISSION
INTO DORA LATER TODAY TO OBTAIN A BETTER WIND ESTIMATE.
 
WATER VAPOR IMAGES SHOW THAT UPPER-LEVEL NORTHEASTERLY WINDS ARE
CONTINUING TO CAUSE SHEAR ON DORA.  ALTHOUGH GLOBAL MODELS DO
WEAKEN THIS FLOW SOMEWHAT DURING THE NEXT DAY OR TWO...DORA WILL BE
MOVING OVER COOLER SSTS AND PROBABLY WILL NOT GET A CHANCE TO TAKE
ADVANTAGE OF THE DECREASED SHEAR.  THE NHC INTENSITY FORECAST WILL
SPLIT THE DIFFERENCE BETWEEN THE STATISTICAL AND DYNAMICAL
MODELS...CALLING FOR STEADY WEAKENING...SIMILAR TO THE PREVIOUS
ADVISORY.  DORA WILL BE OVER SSTS NEAR 21C IN ABOUT 48 HOURS...
LIKELY CAUSING ANY ORGANIZED CONVECTION TO DISAPPEAR AND FOR THE
SYSTEM TO TRANSITION INTO A REMNANT LOW BY THAT TIME.
 
THE CYCLONE CONTINUES MOVING NORTHWESTWARD AT 8 KT ALONG THE
SOUTHWESTERN FLANK OF A DEEP-LAYERED RIDGE.  WHILE THERE IS AN
OCCASIONAL MODEL OUTLIER TAKING DORA CLOSER TO BAJA...THE MAJORITY
OF THE GUIDANCE SHOW A NORTHWESTWARD TRACK FOR THE NEXT SEVERAL
SEVERALS.  THE LATEST NHC FORECAST IS BASICALLY AN UPDATE OF THE
PREVIOUS ADVISORY AND IS JUST TO THE LEFT OF THE MODEL CONSENSUS.
 
ALTHOUGH THE PROBABILITY OF TROPICAL STORM FORCE WINDS FOR SOUTHERN
BAJA CALIFORNIA IS DECREASING...IT IS PRUDENT TO LEAVE THE TROPICAL
STORM WARNING UP FOR NOW UNTIL WE ARE MORE CONFIDENT OF THESE WINDS
STAYING OFFSHORE.   
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  22/1500Z 19.3N 109.4W   75 KT  85 MPH
 12H  23/0000Z 20.0N 110.2W   60 KT  70 MPH
 24H  23/1200Z 21.0N 111.3W   45 KT  50 MPH
 36H  24/0000Z 22.0N 112.5W   35 KT  40 MPH
 48H  24/1200Z 23.1N 113.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  25/1200Z 25.0N 116.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  26/1200Z 26.5N 118.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  27/1200Z...DISSIPATED
 
$$
FORECASTER BLAKE