503 
 WTPA42 PHFO 190243
 TCDCP2
 
 TROPICAL DEPRESSION THREE-C DISCUSSION NUMBER   2
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP032009
 500 PM HST SUN OCT 18 2009
 
 TROPICAL DEPRESSION THREE-C HAS CONTINUED TRACKING WEST.
 
 SATELLITE IMAGERY SHOWS THAT THREE-C REMAINS WELL-ORGANIZED...WITH A
 GOOD CURVED BAND STRUCTURE...BUT CLOUD TOPS HAVE WARMED SINCE THIS
 MORNING. THE 00Z SATELLITE FIXES FROM SAB...CPHC AND JTWC WERE
 CLOSE TOGETHER AND FARTHER WEST THAN EXPECTED BASED ON THE 18Z
 FIXES. WE SUSPECT THE 18Z POSTION MAY HAVE BEEN TOO FAR EAST AND WE
 HAVE RE-BESTED THE POSITION FARTHER WEST. SHIPS GUIDANCE AT 00Z
 SHOWED A HIGH PROBABILITY OF RAPID INTENSIFICATION BUT THE WARMING
 OF THE CLOUD TOPS MAKES RI UNLIKELY IN THE NEAR TERM.
  
 THREE-C HAS CONTINUED MOVING WEST SINCE THIS MORNING...STEERED BY
 DEEP EASTERLY FLOW SOUTH OF THE SUBTROPICAL RIDGE. HOWEVER...A
 STRONG TROUGH ALOFT AND AN ASSOCIATED SURFACE FRONT NEAR MIDWAY ARE
 DIGGING SOUTHEAST. THE MEAN FLOW AHEAD OF THE DIGGING TROUGH WILL
 VEER TO SOUTHEAST AND STEER THREE-C ON A TRACK TOWARD THE WEST
 NORTHWEST GRADUALLY CURVING TOWARD THE NORTHWEST. THE TRACK
 GUIDANCE IS IN GOOD AGREEMENT ON SUCH A TRACK THROUGH 96 HOURS. WE
 HAVE MADE ONLY MINOR ADJUSTMENTS TO OUR FORECAST TRACK...KEEPING
 THREE-C MOVING DOWN THE MIDDLE OF THE ENVELOPE OF THE FAVORED TRACK
 MODEL GUIDANCE. AFTER 96 HOURS...AS THE TROUGH ALOFT MOVES OFF TO
 THE EAST AND RIDGING ALOFT BUILDS IN NORTH OF THE CYCLONE...THREE-C
 WILL TURN BACK TOWARD THE WEST NORTHWEST. THREE-C SHOULD REMAIN
 WELL SOUTHWEST OF THE MAIN HAWAIIAN ISLANDS...BUT THE TRACK DOES
 TAKE IT FAIRLY CLOSE TO JOHNSTON ISLAND IN ABOUT 84 HOURS. THE
 TRACK AND INTENSITY FORECASTS ARE TOO UNCERTAIN AT THIS POINT TO
 HAVE MUCH CONFIDENCE ABOUT WHAT EFFECT THREE-C MIGHT HAVE ON
 JOHNSTON BUT IF OUR FORECAST REMAINS ON TRACK WE MIGHT NEED TO
 CONSIDER A WATCH FOR JOHNSTON ISLAND MONDAY NIGHT.
  
 THREE-C IS OVER 84 DEGREE F WATER...WHICH SHOULD BE AMPLE TO SUPPORT
 DEVELOPMENT...AND WATER TEMPERATURES WILL COOL ONLY ONE OR TWO
 DEGREES OVER THE NEXT FOUR DAYS ALONG OUR FORECAST TRACK. THE SHIPS
 MODEL SHOWS STRONGER SHEAR...20 KT...INITIALLY WITH THE SHEAR
 GRADUALLY DECREASING THROUGH 96 HOURS. MODEL GUIDANCE STILL SHOWS
 THREE-C INTENSIFYING STEADILY FOR THE NEXT 72 HOURS. WE HAVE KEPT
 THIS TREND IN OUR FORECAST BUT THE WARMING CLOUD TOPS MAKE US LESS
 CONFIDENT ABOUT THE INTENSITY TREND.
   
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      19/0300Z  8.8N 157.3W    30 KT
  12HR VT     19/1200Z  9.7N 159.3W    35 KT
  24HR VT     20/0000Z 11.0N 162.0W    40 KT
  36HR VT     20/1200Z 12.6N 164.3W    50 KT
  48HR VT     21/0000Z 14.0N 166.0W    60 KT
  72HR VT     22/0000Z 16.5N 168.5W    65 KT
  96HR VT     23/0000Z 18.0N 170.5W    75 KT
 120HR VT     24/0000Z 19.0N 173.0W    75 KT
  
 $$
 FORECASTER DONALDSON