000
WTNT45 KNHC 040853
TCDAT5
 
TROPICAL STORM EMILY DISCUSSION NUMBER  11
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL052011
500 AM EDT THU AUG 04 2011

DATA FROM THE NOAA G-IV JET AND AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT SHOW THAT EMILY IS NOT WELL ORGANIZED.  THE
CIRCULATION CONTINUES TO BE ELONGATED FROM NORTHEAST TO
SOUTHWEST...AND IT IS VERY WEAK ABOVE 700 MB.  THE JET DATA
INDICATED 300 MB WINDS BLOWING INTO THE SYSTEM DUE TO AN
UPPER-LEVEL LOW OVER EASTERN CUBA...AND THIS IS CONTRIBUTING TO
ABOUT 15 KT OF WESTERLY VERTICAL WIND SHEAR.  ALTHOUGH THE STORM IS
PRODUCING VERY STRONG BURSTS OF CONVECTION...THE AIR FORCE DATA
SUGGEST THAT THE MAXIMUM WINDS ARE STILL AROUND 45 KT.  IT SHOULD
BE NOTED THAT THE AIR FORCE AIRCRAFT HAD TO ABORT ITS MISSION DUE
TO AVIONICS PROBLEMS.

THE CENTER APPEARS TO BE ON THE MOVE AGAIN...WITH THE INITIAL MOTION
A RATHER UNCERTAIN 285/6. THE DYNAMICAL MODELS CONTINUE TO FORECAST
THAT EMILY SHOULD TURN NORTHWESTWARD WITH AN INCREASE IN FORWARD
SPEED DURING THE NEXT 12-24 HR DUE TO A DEVELOPING WEAKNESS IN THE
SUBTROPICAL RIDGE NEAR AND EAST OF THE FLORIDA PENINSULA. THE
GUIDANCE CONTINUES TO HAVE PROBLEMS WITH RUN-TO-RUN
CONSISTENCY...AS THE 00Z RUNS HAVE ALL SHIFTED TO THE EAST OF THE
PREVIOUS FORECASTS. THE NEW FORECAST TRACK WILL NOT SHIFT EASTWARD
DUE TO THE LACK OF CONSISTENCY AND SINCE THE FORECAST NORTHWESTWARD
TURN HAS NOT YET MATERIALIZED. THE NEW FORECAST TRACK IS SIMILAR TO
BUT SLOWER THAN THE PREVIOUS TRACK...AND LIES TO THE LEFT OF THE
CENTER OF THE TRACK GUIDANCE ENVELOPE FROM 12-48 HR. AFTER 72
HR...ALL OF THE GUIDANCE FORECASTS EMILY TO RECURVE NORTHEASTWARD
INTO THE WESTERLIES...AND THIS PART OF THE FORECAST TRACK IS IN THE
MIDDLE OF THE GUIDANCE ENVELOPE.

THE DYNAMICAL MODELS FORECAST THAT THE UPPER-LEVEL LOW OVER CUBA
WILL EVOLVE INTO A CYCLONIC SHEAR AXIS TO THE NORTH OF EMILY.  THE
STORM IS FORECAST TO INTERACT WITH THIS FEATURE FOR THE NEXT 36-48
HR...AND THIS IS LIKELY TO MAINTAIN MODERATE SHEAR OVER EMILY.  IN
ADDITION...WATER VAPOR IMAGERY SHOWS DRY AIR JUST NORTHWEST OF THE
STORM...AND LAND INTERACTION WITH HISPANIOLA AND CUBA IS YET
ANOTHER NEGATIVE FACTOR.  DESPITE THESE NEGATIVES...THE SHIPS...
LGEM...GFDL...AND HWRF MODELS ALL FORECAST STRENGTHENING.  THE NEW
INTENSITY FORECAST CALLS FOR WEAKENING DURING THE FIRST 24 HR DUE
TO SHEAR AND LAND INTERACTION...AND THEN CALLS FOR GRADUAL
STRENGTHENING THROUGH 96 HR SIMILAR TO THE LGEM MODEL.
 
THE CURRENT FORECAST TRACK AND WIND RADII DO NOT REQUIRE A WATCH FOR
SOUTHERN FLORIDA AT THIS TIME.  IF EMILY DOES NOT BEGIN ITS
NORTHWESTWARD TURN SOON...A WATCH COULD BE REQUIRED FOR PARTS OF
SOUTHERN FLORIDA LATER TODAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/0900Z 17.3N  71.7W   45 KT  50 MPH
 12H  04/1800Z 17.9N  72.7W   45 KT  50 MPH
 24H  05/0600Z 20.0N  74.5W   40 KT  45 MPH
 36H  05/1800Z 22.5N  76.2W   45 KT  50 MPH
 48H  06/0600Z 24.7N  77.6W   50 KT  60 MPH
 72H  07/0600Z 28.5N  78.5W   60 KT  70 MPH
 96H  08/0600Z 32.5N  74.5W   65 KT  75 MPH
120H  09/0600Z 36.0N  65.0W   60 KT  70 MPH
 
$$
FORECASTER BEVEN