956 
 WTPZ45 KNHC 201456
 TCDEP5
 TROPICAL STORM KIKO DISCUSSION NUMBER  23
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP152007
 800 AM PDT SAT OCT 20 2007
  
 VISIBLE SATELLITE IMAGERY SHOWS THAT KIKO HAS BECOME BETTER
 ORGANIZED...WITH A WELL-DEFINED CENTRAL DENSE OVERCAST ALMOST
 SURROUNDED BY A SOMEWHAT RAGGED OUTER BAND.  OVERSHOOTING
 CONVECTIVE TOPS IN THE CDO ARE COLDER THAN -80C.  SATELLITE
 INTENSITY ESTIMATES FROM TAFB AND SAB ARE 55 KT...AND THAT IS THE
 INITIAL INTENSITY FOR THIS ADVISORY.  THE CIRRUS OUTFLOW IS FAIR TO
 GOOD IN ALL DIRECTIONS EXCEPT THE WEST...WHERE IT IS POOR.
 
 THE INITIAL MOTION REMAINS 305/4.  KIKO IS CURRENTLY BEING STEERED
 BY A MID-LEVEL RIDGE OVER NORTHERN MEXICO...WHICH IS FORECAST TO
 WEAKEN DURING THE NEXT 24 HOURS AS A DEEP-LAYER TROUGH OVER THE
 WESTERN UNITED STATES AMPLIFIES SOUTHEASTWARD.  THE GUIDANCE HAS
 COME INTO BETTER AGREEMENT ON THE EVOLUTION OF THE TROUGH...WITH
 ALL LARGE-SCALE MODELS EXCEPT THE NOGAPS FORECASTING THE TROUGH TO
 MOVE FAR ENOUGH TO THE EAST TO ALLOW RIDGING TO DEVELOP IN ITS WAKE
 NORTH OF KIKO.  THIS SHOULD TURN KIKO MORE WESTWARD IN THE 48-72 HR
 TIME FRAME.   HOWEVER...THE TRACK GUIDANCE DOES NOT TOTALLY AGREE
 WITH THIS SCENARIO...AS THE GFDL AND HWRF SHOW A NORTHWARD MOTION
 FOR 48 HR OR SO FOLLOWED BY A NORTHWESTWARD MOTION.  THE GFDL HAS A
 GOOD RECENT TRACK RECORD ON STORMS IN THIS AREA...BUT IN THIS CASE
 IT MAY BE DRIVING KIKO TOO MUCH INTO THE MID-LEVEL RIDGE.  THE NEW
 FORECAST TRACK CALLS FOR A NORTHWESTWARD MOTION FOR THE FIRST 48
 HR...FOLLOWED BY A GRADUAL TURN TOWARD THE WEST-NORTHWEST IN BEST
 AGREEMENT WITH THE CCON CONSENSUS MODEL.  AN ALTERNATE SCENARIO
 WOULD BE A NORTHWARD TURN IN THE NEXT 12-24 HR AS THE TROUGH
 APPROACHES FOLLOWED BY A SHARPER TURN TOWARD THE WEST AS THE
 TRAILING RIDGE BUILDS...AS SUGGESTED BY THE GFDN.  THERE REMAINS
 CONSIDERABLE UNCERTAINTY IN THE TRACK FORECAST...ESPECIALLY IN
 REGARDS TO HOW CLOSE KIKO MAY COME TO BAJA CALIFORNIA.
 
 KIKO IS IN AN AREA OF LIGHT VERTICAL WIND SHEAR...AND THAT IS LIKELY
 TO CONTINUE FOR THE NEXT 36 HR OR SO.  ALL GUIDANCE FORECASTS
 STRENGTHENING DURING THAT TIME...AND THE NEW INTENSITY FORECAST NOW
 CALLS FOR KIKO TO PEAK AT 80 KT IN 36 HR.  AFTER THAT TIME...
 INCREASING SHEAR AND COOLING SEA SURFACE TEMPERATURES ALONG THE
 FORECAST TRACK SHOULD CAUSE WEAKENING.  THE SSTS ARE BELOW 24C
 ALONG THE FORECAST TRACK WEST OF 110W...SO THE NEW INTENSITY
 FORECAST SHOWS A FASTER WEAKENING THAN THE PREVIOUS ADVISORY.
  
 WIND RADII HAVE BEEN REVISED BASED ON JUST-RECEIVED QUIKSCAT DATA.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      20/1500Z 18.1N 106.6W    55 KT
  12HR VT     21/0000Z 18.7N 107.2W    65 KT
  24HR VT     21/1200Z 19.6N 107.8W    75 KT
  36HR VT     22/0000Z 20.4N 108.6W    80 KT
  48HR VT     22/1200Z 20.8N 109.5W    75 KT
  72HR VT     23/1200Z 21.5N 112.0W    65 KT
  96HR VT     24/1200Z 22.0N 115.5W    45 KT
 120HR VT     25/1200Z 22.5N 119.5W    30 KT
  
 $$
 FORECASTER BEVEN