WDPN31 PGTW 120900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (GUCHOL) WARNING 
NR 06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 05W (GUCHOL), LOCATED APPROXIMATELY 280 NM 
EAST OF YAP, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE 
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY CONTINUES 
TO SHOW A STRONG MID-LEVEL CIRCULATION CENTER WHICH IS OBSCURING 
THE LOW-LEVEL CIRCULATION CENTER (LLCC). IN THE LAST FEW FRAMES OF 
MSI NEWLY FORMING OVERSHOOTING TOPS ARE EVIDENT. THE INITIAL 
POSITION IS BASED ON THESE FEATURES WITH POOR CONFIDENCE. THE 
INITIAL INTENSITY IS BASED ON AN AVERAGE OF DVORAK ESTIMATES 
RANGING FROM 25-45 KNOTS FROM RJTD, KNES, AND PGTW. UPPER-LEVEL 
ANALYSIS INDICATES THAT THE TROPICAL UPPER TROPOSPHERIC TROUGH 
(TUTT) CELL TO THE NORTHEAST IS BOTH SUPPRESSING AND AIDING IN 
OUTFLOW. THERE IS A RELATIVELY DRY AND CONVERGENT PRESSURE ALONG 
THE NORTHERN PERIPHERY OF THE SYSTEM WHICH IS SUPPRESSING DEEP 
CONVECTION OVER THE NORTH-NORTHWESTERN SECTORS. HOWEVER, OUTFLOW TO 
THE NORTHEAST OF THE LLCC IS SLIGHTLY ENHANCED BY THE DIVERGENT 
SIDE OF THE TUTT CELL. THESE COMPETING FORCES MAY BE THE REASON FOR 
THE SYSTEM'S CONTINUED SLOW DEVELOPMENT. TS 05W IS CURRENTLY 
TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP, EAST-WEST 
ORIENTED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TS 05W IS FORECAST TO TRACK WEST-NORTHWESTWARDS ALONG THE 
SOUTHERN PERIPHERY OF THE FIRMLY ENTRENCHED STEERING STR DURING THE 
NEXT THREE DAYS. GRADUAL INTENSIFICATION IS EXPECTED AS IT TRACKS 
OVER WARM WATER AND OUTFLOW IMPROVES INTO AN APPROACHING MID-
LATITUDE TROUGH. NOGAPS REMAINS THE RIGHT-MOST OUTLIER OF AN 
OTHERWISE RELATIVELY CLOSELY GROUPED THREE-DAY ENVELOPE.
   C. IN THE EXTENDED PERIOD, TS 05W IS FORECAST TO TRACK MORE 
NORTHWESTWARDS AS IT ROUNDS THE SOUTHWESTERN PERIPHERY OF THE STR 
AND BEGINS TO TURN MORE POLEWARD AHEAD OF THE APPROACHING MID-
LATITUDE TROUGH EXPECTED TO DEEPEN OVER EASTERN CHINA NEAR TAU 72. 
AVAILABLE MODEL GUIDANCE DIVERGES AROUND TAU 72 AND THERE IS LOW 
CONFIDENCE IN THE RE-CURVE POINT. NOGAPS TURNS THE SYSTEM POLEWARD 
AT TAU 96, WHICH IS UNLIKELY DUE TO THE STRONG STR. THE JTWC 
FORECAST IS IN AGREEMENT WITH MODEL CONSENSUS BUT POSITIONED 
SLIGHTLY LEFT OF CONSENSUS TO OFF-SET THE UNLIKELY NOGAPS SOLUTION, 
FAVORING A MORE WESTWARD TRACK. THERE IS LOW OVERALL FORECAST TRACK 
CONFIDENCE DUE TO THE POOR INITIALIZATION OF THE LLCC AND MODEL 
SPREAD AFTER TAU 72.//
NNNN