693 
 WTNT44 KNHC 110232
 TCDAT4
 TROPICAL STORM IRENE DISCUSSION NUMBER  26
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 11 PM EDT WED AUG 10 2005
 
 IRENE'S CLOUD PATTERN HAS BECOME SLIGHTLY BETTER ORGANIZED THIS
 EVENING.  A CONVECTIVE BAND OVER THE EASTERN PORTION OF THE SYSTEM
 WRAPS NEARLY HALFWAY AROUND THE CIRCULATION.  DVORAK INTENSITY
 ESTIMATES ARE A CONSENSUS 35 KT FROM TAFB...SAB...AND AFWA.  THIS
 SUPPORTS RE-UPGRADING THE CYCLONE TO TROPICAL STORM STATUS.  THE
 UPPER-TROPOSPHERIC OUTFLOW IS BECOMING BETTER DEFINED EXCEPT TO THE
 SOUTH WHERE IT IS BEING IMPEDED BY AN UPPER-LEVEL CYCLONE TO THE
 SOUTHWEST OF THE STORM.  WATER VAPOR IMAGERY AND ANALYSES FROM THE
 UNIVERSITY OF WISCONSIN CIMSS SHOW THAT THE NORTHERLY MID- TO
 UPPER-LEVEL FLOW THAT HAD BEEN DISRUPTING THE TROPICAL CYCLONE IS
 ABATING AND THAT IRENE IS MOVING INTO AN AREA OF DECREASING
 VERTICAL SHEAR.  STRENGTHENING IS FORECAST...AS IN THE PREVIOUS
 ADVISORY.  AS USUAL...THE FORECAST WIND SPEEDS IN THE 3 TO 5 DAY
 TIME FRAME HAVE CONSIDERABLE UNCERTAINTY OWING TO A LACK OF SKILL
 IN LONGER-RANGE TROPICAL CYCLONE INTENSITY PREDICTION.  
 
 RECENT CENTER FIXES FROM BOTH GEOSTATIONARY AND MICROWAVE IMAGERY
 ARE SOMEWHAT TO THE NORTH OF THE PREVIOUS TRACK.  HOWEVER...FOR
 CONTINUITY'S SAKE...I HAVE ADJUSTED THE CURRENT MOTION ONLY
 SLIGHTLY TO THE RIGHT...290/11.  THE MAIN STEERING FEATURE THAT
 CONCERNS US IS A MID-TROPOSPHERIC RIDGE THAT THE GLOBAL MODELS ARE
 FORECASTING TO BUILD NEAR AND JUST EAST OF THE U.S. MID-ATLANTIC
 STATES IN 3 TO 5 DAYS.  IT IS TOO EARLY TO DETERMINE WHETHER THIS
 RIDGE WILL DRIVE IRENE TO THE SOUTHEAST U.S. COAST.  IT IS STILL
 POSSIBLE THAT THE TROPICAL CYCLONE WILL BE ABLE TO MOVE MORE
 NORTHWARD INTO A WEAKNESS IN THE RIDGE...AS SUGGESTED BY SOME OF
 THE TRACK GUIDANCE SUCH AS THE U.K. MET. OFFICE GLOBAL MODEL AND
 THE LATEST GFDL RUN...OR MOVE MORE WESTWARD AND REACH THE COAST AS
 SHOWN BY THE ECMWF AND GFDN.  THE OFFICIAL FORECAST TRACK HAS BEEN
 SHIFTED A LITTLE TO THE RIGHT OF THE PREVIOUS ONE...BUT IS STILL
 WELL TO THE LEFT OF THE DYNAMICAL MODEL CONSENSUS.  THE NHC
 FORECAST TRACK IS ALSO VERY SIMILAR TO THE LATEST FSU SUPERENSEMBLE
 TRACK.
 
 FORECASTER PASCH
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      11/0300Z 23.5N  59.8W    35 KT
  12HR VT     11/1200Z 24.2N  61.5W    40 KT
  24HR VT     12/0000Z 25.4N  63.8W    45 KT
  36HR VT     12/1200Z 26.3N  65.7W    50 KT
  48HR VT     13/0000Z 27.2N  67.5W    55 KT
  72HR VT     14/0000Z 28.5N  70.0W    60 KT
  96HR VT     15/0000Z 30.5N  72.5W    65 KT
 120HR VT     16/0000Z 32.5N  75.0W    70 KT
 
  
 $$