WTPA43 PHFO 190905
TCDCP3

TROPICAL DEPRESSION TWO-C DISCUSSION NUMBER   2
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP022006
1100 PM HST MON SEP 18 2006

TROPICAL DEPRESSION TWO-C CONTINUES TO STRENGTHEN AS IT MOVES 
WESTWARD WELL SOUTH OF THE HAWAIIAN ISLANDS. OVER THE PAST SIX 
HOURS...TWO-C HAS STARTED TO SHOW SIGNS OF BETTER ORGANIZATION AND 
CONVECTION NEAR THE CENTER HAS INCREASED. CLOUD COVER ASSOCIATED 
WITH THE INCREASE IN CONVECTION HAS ALSO MADE IT MORE DIFFICULT TO 
LOCATE THE EXACT CENTER. THE MAXIMUM WIND SPEED WAS INCREASED TO 30 
KNOTS BASED ON AGENCY FIXES OF 1.5 AND QUIKSCAT DATA. WINDSAT DATA 
AT 0416 UTC DID INDICATE SOME 40 KNOT WINDS NORTH OF THE CENTER NEAR 
10.5N LATITUDE...BUT THESE SEEMED UNREASONABLE AND WERE DISCOUNTED. 

THE FORECAST TRACK OF TWO-C HAS BEEN ADJUSTED SOUTHWARD OR TO THE 
LEFT OF THE PREVIOUS TRACK...WHICH RELIED EXCLUSIVELY ON THE BETA 
ADVECTION AND PERSISTENCE/CLIMATOLOGY MODELS. THE CURRENT GUIDANCE 
SUITE...INCLUDING GFDL...GFS...UKMET...AND CONU FORECASTS...SHOWS A 
CONSIDERABLE SHIFT TOWARD THE SOUTH BEYOND 36 HOURS...TAKING TWO-C 
ON A MORE WESTWARD TRACK. DEEP LAYER MEAN WINDS THAT WOULD HELP TO 
STEER THIS STORM ARE EXPECTED TO REMAIN ALMOST FROM DUE EAST...WHICH 
ADDS CREDENCE TO THE MORE WESTWARD MOVEMENT. THE CURRENT FORECAST 
TRACK REMAINS CLOSE TO THE PREVIOUS TRACK THROUGH 36 HOURS AND 
SHIFTS CLOSER TO THE GFDL TRACK THEREAFTER...WHICH IS NOT QUITE AS 
FAR SOUTH AS THE CONU.

WIND RADII WERE ALSO EXPANDED PRIMARILY THROUGH 36 HOURS IN RESPONSE 
TO THE INCREASED IN INTENSITY AND QUIKSCAT DATA. WIND RADII REMAIN 
LARGEST IN THE NORTHEAST QUADRANT OF THE STORM...WHERE THE GRADIENT 
BETWEEN THE STORM AND HIGH PRESSURE TO THE NORTHEAST IS THE 
STRONGEST.

THE FORECAST INTENSITY WAS INCREASED THROUGH 36 HOURS IN RESPONSE TO 
THE INCREASE IN INITIAL INTENSITY. THERE IS VERY LITTLE SHEAR NEAR 
TWO-C AT THE MOMENT AND MODELS ARE IN GOOD AGREEMENT THAT TWO-C WILL 
ENCOUNTER LITTLE TO NO VERTICAL SHEAR OVER THE NEXT SEVERAL DAYS.  
EXPERIMENTAL VERTICAL SHEAR ESTIMATES FROM UW-CIMMS CONCUR...AND 
LIST DEVELOPMENT OUTLOOK AS VERY FAVORABLE IN THE NEAR TERM. TWO-C 
IS SPINNING OVER SSTS OF 28 DEGREES CELSIUS AND GIVEN ITS FORECAST 
TRACK WILL REMAIN OVER WATER NEAR 28 DEGREES CELSIUS. ALL SIGNS 
THEREFORE...ARE FAVORABLE FOR ADDITIONAL DEVELOPMENT. AS IT 
STANDS...TWO-C IS EXPECTED TO BECOME A TROPICAL STORM EARLY 
TUESDAY...AND REACH HURRICANE STRENGTH WEDNESDAY.

ITS PROJECTED PATH THROUGH 120 HOURS KEEPS TWO-C OVER WATER AND AWAY 
FROM ANY MAJOR PACIFIC ISLANDS. THE SOUTHWARD ADJUSTMENT OF THE 
FORECAST TRACK AFTER 36 HOURS ALSO PLACES TWO-C FURTHER AWAY FROM 
JOHNSTON ISLAND.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      19/0900Z 10.0N 158.1W    30 KT
 12HR VT     19/1800Z 10.3N 159.8W    40 KT
 24HR VT     20/0600Z 10.8N 162.0W    45 KT
 36HR VT     20/1800Z 11.4N 164.2W    55 KT
 48HR VT     21/0600Z 12.0N 166.5W    65 KT
 72HR VT     22/0600Z 13.4N 171.1W    75 KT
 96HR VT     23/0600Z 14.4N 174.3W    80 KT
120HR VT     24/0600Z 14.8N 176.5W    80 KT
 
$$
FORECASTER TANABE/HOUSTON