045 
 WTPZ44 KNHC 160833
 TCDEP4
 TROPICAL STORM HECTOR DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP092006
 200 AM PDT WED AUG 16 2006
  
 THE CYCLONE HAS BEEN MAINTAINING DEEP CORE CONVECTION ALL EVENING
 WITH INTERMITTENT BANDING...AND MICROWAVE PASSES SUGGEST THAT THE
 CENTER IS JUST WITHIN THE CENTRAL CONVECTIVE MASS.  DVORAK
 CLASSIFICATIONS AT 06Z WERE T2.5...35 KT...FROM ALL AGENCIES...WITH
 DATA-T NUMBERS AS HIGH AS T3.5.  A QUIKSCAT PASS AT 01Z CAUGHT SOME
 OF THE EASTERN SEMICIRCLE...AND THERE WERE A LOT OF 30 KT VECTORS
 OUTSIDE THE HEAVY CONVECTION IN THE SOUTHEAST QUADRANT...WITH ONE
 VECTOR NEAR 35 KT.  THE PASS MISSED THE DEEP CONVECTION AND LIKELY
 THE STRONGEST WINDS...AND THE INITIAL INTENSITY IS THEREFORE SET TO
 40 KT.  
 
 IF THE CENTER IS WHERE I THINK IT IS...THE INITIAL MOTION IS A
 LITTLE TO THE LEFT OF THE PREVIOUS TRACK...AT 270/13.  THERE HAS
 BEEN ONLY A SLIGHT SOUTHWARD ADJUSTMENT OF THE PREVIOUS FORECAST
 TRACK...AND THE BASIC SYNOPTIC REASONING IS UNCHANGED.  HECTOR IS
 MOVING ALONG THE SOUTHWEST PERIPHERY OF THE SUBTROPICAL RIDGE THAT
 EXTENDS WESTWARD FROM MEXICO.  GLOBAL MODELS ALL SHOW THE RIDGE
 ERODED BY A MIDDLE- TO UPPER-LEVEL TROUGH NEAR 130W OVER THE NEXT
 COUPLE OF DAYS...BUT DESPITE THIS EXHIBIT A FAIRLY LARGE SPREAD IN
 THE FORECAST TRACKS OF HECTOR.  THE RIGHTMOST OUTLIERS ARE THE
 NOGAPS AND GFNI...WHICH START OFF THE CYCLONE WITH AN IMMEDIATE
 NORTHWESTWARD TRACK THAT SEEMS INCONSISTENT WITH THE CURRENT
 MOTION.  ON THE LEFT IS THE UKMET...WHICH MARCHES HECTOR QUICKLY
 OFF TO THE WEST AND SUBSEQUENTLY MISSES THE TROUGH.  THE INITIAL
 WESTWARD MOTION IN THE UKMET ALSO SEEMS INCONSISTENT WITH PRESENT
 TRENDS.  THIS LEAVES THE GFS AND GFDL IN THE MIDDLE...AND THE
 OFFICIAL FORECAST IS CLOSE TO A BLEND OF THESE TWO MODELS THROUGH
 96 HOURS.  NEAR THE END OF THE FORECAST PERIOD...AS HECTOR
 PRESUMABLY WEAKENS...THE OFFICIAL FORECAST BENDS SLIGHTLY BACK TO
 THE WEST IN ACCORD WITH THE SHALLOW BAM.
 
 THERE STILL APPEARS TO BE SOME NORTHEASTERLY SHEAR OVER HECTOR...
 ALTHOUGH THIS SHEAR IS FORECAST TO ABATE SOMEWHAT OVER THE NEXT DAY
 OR SO.  HECTOR ALSO HAS ALMOST TWO DAYS OVER WARM WATERS.  THE GFDL
 BRINGS HECTOR TO HURRICANE STRENGTH IN 48 HOURS...BUT THE SHIPS
 GUIDANCE TOPS OUT AT 54 KT.  THE MAIN NEGATIVE PREDICTORS SEEM TO
 BE ASSOCIATED WITH THE DISTRIBUTION OF COLD SATELLITE PIXEL
 COUNTS...WHICH I CANNOT RECONCILE WITH WHAT LOOKS LIKE A DECENT
 SATELLITE PRESENTATION.  GIVEN THE INTENSIFICATION OVERNIGHT...I AM
 INCLINED TO FAVOR THE MORE AGGRESSIVE GFDL...AND NOTE THAT THE FSU
 SUPERENSEMBLE ALSO BRINGS HECTOR TO HURRICANE STRENGTH IN 36 HOURS. 
 BY 72 HOURS...HECTOR IS EXPECTED TO BE DECAYING OVER COOLER WATERS. 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      16/0900Z 13.1N 116.5W    40 KT
  12HR VT     16/1800Z 13.4N 118.3W    50 KT
  24HR VT     17/0600Z 14.0N 120.4W    60 KT
  36HR VT     17/1800Z 14.6N 122.4W    65 KT
  48HR VT     18/0600Z 15.5N 124.0W    70 KT
  72HR VT     19/0600Z 17.5N 127.5W    60 KT
  96HR VT     20/0600Z 19.5N 130.5W    45 KT
 120HR VT     21/0600Z 21.0N 134.0W    30 KT
  
 $$
 FORECASTER FRANKLIN