WTPA42 PHFO 092101
TCDCP2

TROPICAL STORM FELICIA DISCUSSION NUMBER  25
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP082009
1100 AM HST SUN AUG 09 2009

FELICIA HAS RAPIDLY WEAKENED OVERNIGHT...BUT IT IS FAR FROM BEING
DEAD. AIR FORCE RECONNAISSANCE AIRCRAFT MEASURED 56 KT AT 700 MB
WITHIN AN AREA STILL CONVECTIVE LY ACTIVE IN THE NORTHEAST QUADRANT
AT ABOUT 1745 UTC.  ON THE NEXT LEG IN THAT QUADRANT...FLYING AT
850 MB...FLIGHT-LEVEL WINDS REACHED 65 KT...BUT IN AN AREA WITH
LESS VIGOROUS CONVECTION...BUT A DROPSONDE WITHIN CONVECTION
MEASURED A MEAN BOUNDARY LAYER WIND OF 57 KT.  THAT WOULD ROUGHLY
CORRESPOND TO A SURFACE WIND ESTIMATE OF ABOUT 45 KT...AND THAT
WILL BE THE ADVISORY INTENSITY.  GIVEN THE OVERALL CONVECTIVE
COLLAPSE OF THE SYSTEM...WE ARE ASSUMING THE USUAL REDUCTIONS TO
THE SURFACE OF THE VARIOUS FLIGHT-LEVEL WINDS ARE NOT APPLICABLE. 
THE ADVISORY INTENSITY IS GENERALLY CONSISTENT WITH A BLEND OF A
WIDE VARIETY OF DVORAK T AND CI NUMBERS.

EARLIER THIS MORNING THE FORWARD MOTION TOOK ON A LARGER NORTHERN
COMPONENT...BUT RECENT GOES SATELLITE LOOPS SHOW FELICIA IS NOW
MOVING JUST NORTH OF DUE WEST...OR 280/12. THIS WILL LIKELY
CONTINUE AS THE REDUCTION IN SYSTEM DEEP CONVECTION MAKES FELICIA
MORE SUSCEPTIBLE TO LOW LEVEL TRADE WIND STEERING FLOW.  MOST OF
THE TRACK MODELS TAKE FELICIA WESTWARD AND OVER THE HAWAIIAN
ISLANDS WITHIN THE NEXT TWO DAYS...WITH ONLY THE GFS FORECASTING
THE CENTER TO PASS MORE SLOWLY TO THE NORTH OF THE ISLANDS.  THE
OFFICIAL TRACK IS ONLY A SLIGHT ADJUSTMENT NORTHWARD OUT OF RESPECT
TO THE GFS...BUT IS VERY CLOSE TO THE MODEL CONSENSUS AND IS MOST
IN AGREEMENT WITH THE GFDL.

THE TRACK OF FELICIA WILL CONTINUE TO TAKE IT THROUGH AN ENVIRONMENT
OF STRONG WESTERLY SHEAR AND OVER SLOWLY WARMING SSTS...WHICH WOULD
LIKELY PRECLUDE RESTRENGTHENING AS SHOWN BY ALL OF THE INTENSITY
MODELS...SOME OF WHICH SHOW DISSIPATION WITHIN THE NEXT COUPLE OF
DAYS.  HOWEVER...GIVEN THAT CONVECTION IS PERSISTING IN THE
NORTHEAST QUADRANT DESPITE THE SHEAR...THE OFFICIAL FORECAST CALLS
FOR A MORE GRADUAL DECLINE TO A DEPRESSION WHILE PASSING OVER
HAWAII.  THERE IS STILL A CHANCE FELICIA COULD REACH HAWAII AS A
LOW-END TROPICAL STORM.
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/2100Z 21.0N 147.1W    45 KT
 12HR VT     10/0600Z 21.1N 149.0W    40 KT
 24HR VT     10/1800Z 21.1N 151.3W    35 KT
 36HR VT     11/0600Z 21.1N 153.7W    35 KT
 48HR VT     11/1800Z 21.2N 156.1W    30 KT
 72HR VT     12/1800Z 21.5N 160.5W    30 KT
 96HR VT     13/1800Z 22.5N 164.5W    25 KT...DISSIPATING
120HR VT     14/1800Z 24.0N 168.5W    20 KT...REMNANT LOW
 
$$
FORECASTER POWELL/KNABB