WDPN31 PGTW 170300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION (TD) 12W/ 
WARNING NR 08//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 170000Z8 TO 200000Z2 AUG 2003.
   A. TROPICAL DEPRESSION (TD) 12W, LOCATED APPROXIMATELY 30 NM
NORTHWEST OF ANDERSON AFB, GUAM, HAS TRACKED NORTHWESTWARD
AT 14 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS
BASED ON 162330Z5 MULTISPECTRAL SATELLITE IMAGERY. THE
WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY
ESTIMATES OF 25 KNOTS. TD 12W CONTINUES TO ORGANIZE WITH
A RECENT 162332Z7 SSM/I PASS SHOWING DEEP CYCLING CONVECTION
BEGINNING TO CONSOLIDATE OVER THE CENTER OF THE STORM. ANIMATED
MULTISPECTRAL SATELLITE SHOWS THAT CONVECTION HAS INCREASED
IN THE PAST 6 HOURS.
   B. TD 12W IS FORECAST TO TRACK NORTHWESTWARD UNDER THE
SOUTHWEST QUADRANT OF THE LOW TO MID-LEVEL STEERING RIDGE TO
THE NORTH. AVAILABLE DYNAMIC AIDS, CONSISTING OF NOGAPS, NCEP
(GFS), EGRR, AFWA AND COAMPS ARE IN VERY GOOD AGREEMENT WITH THIS
FORECAST SCENARIO. AFWA IS THE SOLE OUTLIER WITH AN UNREALISTIC
FORECAST SOLUTION EQUATORWARD OF THE FORECAST TRACK. THIS FORECAST
IS BASED ON A BLEND OF PERSISTENCE AND A CONSENSUS OF THE AVAILABLE
DYNAMIC AIDS. 
   C. ANALYSIS OF THE UW CIMSS UPPER LEVEL WINDS CHART SHOWS THAT
THE UPPER LEVEL LOW TROUGH NORTHWEST OF THE SYSTEM IS MOVING AWAY
FROM TD 12W ALLOWING FOR AN IMPROVING ENVIRONMENT ALOFT. TD 12W IS
FORECAST TO BEGIN TO INTENSIFY AT A CLIMATOLOGICAL RATE FOR MOST OF
THE FORECAST PERIOD AS IT ENCOUNTERS THE MORE FAVORABLE UPPER LEVEL
ENVIRONMENT. LATE IN THE FORECAST PERIOD, TD 12W IS LIKELY TO
EXPERIENCE A MORE MARGINAL ENVIRONMENT OF INCREASING VERTICAL SHEAR
CAUSING A SLOW DOWN IN INTENSIFICATION RATE.
  D. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGED
SIZED SYSTEM.
FORECAST TEAM: GRUBER/SANTOS/HEATH/BAK/EDBERG/COOK//