WDPN32 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (LINFA) WARNING NR 
31//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 10W (LINFA), LOCATED APPROXIMATELY 45 NM 
NORTH-NORTHEAST OF HONG KONG, HAS TRACKED WESTWARD AT 10 KNOTS OVER 
THE PAST SIX HOURS. TS 10W HAS CONTINUED TO TRACK WESTWARD PARALLEL 
TO THE COAST OF CHINA AS IT MOVES TOWARD THE HONG KONG VICINITY. 
SURFACE OBSERVATIONS FROM HONG KONG (VHHH) INDICATE NORTHWESTERLY 
WINDS AT 20 TO 25 KNOTS SUSTAINED WITH MINIMUM SLP OF 995 MB. 
ANIMATED INFRARED SATELLITE IMAGERY INDICATES SIGNIFICANT WEAKENING 
OF DEEP CONVECTION DUE TO LAND INTERACTION AND RADAR IMAGERY REVEALS 
A BROADENING LOW-LEVEL CIRCULATION CENTER WITH CURVED BANDING OVER 
THE NORTHERN SEMI-CIRCLE. BASED ON RADAR FIXES, THERE IS FAIR 
CONFIDENCE IN THE CURRENT POSITION. THE CURRENT INTENSITY IS 
ASSESSED AT 55 KNOTS, SLIGHTLY HIGHER THAN RJTD'S DVORAK INTENSITY 
ESTIMATE OF 45 KNOTS. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM IS 
LOCATED IN AN AREA OF LOW TO MODERATE (10 TO 20 KNOT) VWS OFFSET BY 
GOOD POLEWARD OUTFLOW, ENHANCED BY AN UPPER-LEVEL TROUGH SITUATED 
OVER EASTERN CHINA. TROPICAL STORM LINFA IS TRACKING ALONG THE 
WESTERN PERIPHERY OF THE MID-LEVEL STR EXTENSION.
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM 
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS LINFA WILL MAINTAIN A WESTWARD TO WEST-SOUTHWESTWARD TRACK 
ALONG THE SOUTHEASTERN COAST OF CHINA THROUGH TAU 24. TS 10W WILL 
WEAKEN SIGNIFICANTLY DUE TO LAND INTERACTION THROUGH THE FORECAST 
PERIOD AND IS EXPECTED TO DISSIPATE BY TAU 48. THE REMNANTS ARE 
FORECAST TO BECOME QUASI-STATIONARY AS LOW-LEVEL WESTERLIES 
STRENGTHEN SOUTH OF THE SYSTEM AFTER TAU 36. DUE TO THE COMPLEX 
STEERING ENVIRONMENT, MODEL GUIDANCE IS IN FAIR AGREEMENT AFTER TAU 
24, THEREFORE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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