718 
 WTPZ44 KNHC 271434
 TCDEP4
  
 HURRICANE HILARY DISCUSSION NUMBER  26
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092011
 800 AM PDT TUE SEP 27 2011
  
 AFTER DECREASING OVERNIGHT...DEEP CONVECTION HAS INCREASED AGAIN
 NEAR THE CENTER OF HILARY...EVEN THOUGH AN EYE IS NO LONGER
 APPARENT IN INFRARED IMAGERY OR THE FIRST VISIBLE IMAGES. THE
 INITIAL INTENSITY IS HELD AT 100 KT BASED ON A BLEND OF 12Z DVORAK
 CI- AND FINAL-T NUMBERS FROM TAFB AND SAB. AS HILARY MOVES OVER
 COOLER WATERS IN THE NEXT DAY OR SO...SLOW WEAKENING IS EXPECTED...
 FOLLOWED BY STEADY WEAKENING AFTER THE CYCLONE CROSSES THE 26C
 ISOTHERM IN ABOUT 36 HOURS. OUTPUT FROM THE SHIPS MODEL SHOWS
 VERTICAL SHEAR INCREASING RAPIDLY AROUND 48 HOURS AND CONTINUING
 THROUGH THE REMAINDER OF THE PERIOD. THIS SHEAR...IN COMBINATION
 WITH HILARY MOVING OVER MUCH COLDER WATERS BY DAY 3 AND BEYOND
 SHOULD RESULT IN RAPID WEAKENING TO A REMNANT LOW BY 4 DAYS. THE
 NHC INTENSITY LIES BETWEEN THE OLD ONE AND THE LGEM THROUGH 36
 HOURS...AND IS CLOSE TO THE LGEM BEYOND THAT TIME. 
 
 THE INITIAL MOTION ESTIMATE IS 270/09. HILARY SHOULD TURN TOWARD THE
 WEST-NORTHWEST AND SLOW DOWN LATER TODAY AS THE RIDGE TO THE NORTH
 CONTINUES TO WEAKEN. AFTER THAT TIME A SHARP TURN TOWARD THE NORTH
 IS EXPECTED BY 36 HOURS AS HILARY BEGINS TO INTERACT WITH AN
 AMPLIFYING MID-LEVEL LOW CURRENTLY LOCATED NEAR 28N 129W.
 OVERALL...THE SPREAD OF THE TRACK GUIDANCE HAS DECREASED THIS
 CYCLE...AS THE LATEST RUN OF THE GFS SHOWS HILARY BEING PULLED A
 LITTLE FARTHER WESTWARD BY THE MID-LEVEL LOW LATE IN THE PERIOD AND
 HAS SHIFTED ITS TRACK WESTWARD TOWARD THE REST OF THE GUIDANCE
 SUITE. THE ONLY CHANGE TO THE NHC TRACK FORECAST IS A SMALL SHIFT
 TO THE LEFT THROUGH 48 HOURS TO ACCOUNT FOR THE INITIAL POSITION
 AND MOTION. THE NEW NHC TRACK IS A LITTLE TO THE EAST OF THE TVCE
 CONSENSUS AND THE ECMWF THROUGH 96 HOURS...AND IS CLOSE TO THE GFS
 ENSEMBLE MEAN AT DAY 5. 
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  27/1500Z 16.8N 116.4W  100 KT 115 MPH
  12H  28/0000Z 17.1N 117.2W   95 KT 110 MPH
  24H  28/1200Z 17.9N 117.6W   85 KT 100 MPH
  36H  29/0000Z 19.0N 117.7W   75 KT  85 MPH
  48H  29/1200Z 20.2N 117.7W   65 KT  75 MPH
  72H  30/1200Z 23.0N 118.0W   45 KT  50 MPH
  96H  01/1200Z 25.0N 118.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  02/1200Z 27.0N 118.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER BRENNAN