207 
 WTPZ44 KNHC 171444
 TCDEP4
 HURRICANE HECTOR DISCUSSION NUMBER   8
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP092006
 800 AM PDT THU AUG 17 2006
  
 ENHANCED INFRARED IMAGERY DEPICTS THAT A CENTRAL DENSE OVERCAST
 FEATURE HAS DEVELOPED DURING THE PAST 6 HOURS...WITH A
 WELL-DEVELOPED WHITE BAND OVER THE EASTERN SEMICIRCLE OF THE
 TROPICAL CYCLONE. DVORAK INTENSITY ESTIMATES HAVE INCREASED TO 77
 KT AND 65 KT FROM TAFB AND SAB RESPECTIVELY...AND ADT CURRENT
 INTENSITY ESTIMATES SUGGEST HECTOR IS SLIGHTLY STRONGER THAN 70 KT.
 THE INITIAL INTENSITY IS INCREASED TO 75 KT. WATER VAPOR IMAGERY
 INDICATES AN IMPRESSIVE OUTFLOW CHANNEL OVER THE SOUTHERN HALF OF
 THE SYSTEM...WITH LIGHT UPPER-LEVEL EASTERLIES OVER THE REMAINING
 PORTIONS. INTENSITY MODELS SUGGEST NO SIGNIFICANT CHANGES IN THE
 ENVIRONMENT OVER THE NEXT 36 HOURS...THEREFORE...A LITTLE MORE
 INTENSIFICATION IS FORECAST. AFTERWARD...GRADUAL WEAKENING IS
 EXPECTED AS THE TROPICAL CYCLONE BEGINS TO MOVE OVER COOLER WATERS
 AND WITHIN A LESS FAVORABLE THERMODYNAMIC ENVIRONMENT. BY DAY
 3...MODELS CONTINUE TO INDICATE AN INCREASE IN SOUTHWESTERLY SHEAR
 AS A MID- TO UPPER-LEVEL TROUGH MOVES NORTHEAST OF HAWAII...ALONG
 140W. THIS SCENARIO COULD INFLUENCE RAPID WEAKENING THROUGH THE
 REMAINDER OF THE FORECAST.
  
 INITIAL MOTION IS ESTIMATED AT 290/11.  HECTOR IS ON THE
 SOUTHWESTERN PERIPHERY OF A DEEP LAYER RIDGE EXTENDING OVER THE
 EASTERN PACIFIC TO 27N130W FROM THE SOUTHWESTERN UNITED STATES. THE
 SYSTEM SHOULD CONTINUE ON A GENERAL WEST-NORTHWESTWARD MOTION FOR
 THE NEXT 48 HOURS...TURNING MORE NORTHWESTWARD THEREAFTER AS A
 WEAKNESS IN THE RIDGE BECOMES MORE PRONOUNCED.  THE OFFICIAL
 FORECAST FOLLOWS THIS SCENARIO...AND IS BASED ON A CONSENSUS OF THE
 DYNAMICAL MODELS...WITH LESS EMPHASIS ON THE UKMET.
  
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      17/1500Z 14.7N 121.1W    75 KT
  12HR VT     18/0000Z 15.3N 122.8W    80 KT
  24HR VT     18/1200Z 16.2N 124.9W    80 KT
  36HR VT     19/0000Z 17.1N 126.9W    75 KT
  48HR VT     19/1200Z 18.0N 128.9W    70 KT
  72HR VT     20/1200Z 20.0N 132.0W    55 KT
  96HR VT     21/1200Z 21.5N 134.0W    35 KT
 120HR VT     22/1200Z 22.5N 136.0W    25 KT
  
 $$
 FORECASTER ROBERTS/KNABB