WDPN31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (PAKHAR)
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM 16W (PAKHAR), LOCATED APPROXIMATELY 169 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 13 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED MULTI-SPECTRAL SATELLITE IMAGERY 
DEPICTS CONVECTIVE BANDING WRAPPING AROUND THE WESTERN EDGE OF THE 
LLCC WITH PERSISTENT DEEP CONVECTION PRESENT OVER THE CENTER. A 
242210Z 91 GHZ SSMIS MICROWAVE IMAGE SHOWS DEEP CONVECTIVE BANDING 
IN THE WESTERN SEMI-CIRCLE WRAPPING INTO A CENTRAL CONVECTIVE MASS 
LOCATED TO THE SOUTHWEST OF THE LLCC. THE INITIAL POSITION IS PLACED 
WITH HIGH CONFIDENCE BASED ON THE MICROWAVE IMAGE AND THE PGTW 
POSITION FIX. THE INITIAL INTENSITY OF 40 KNOTS IS HEDGED ABOVE 
MULTIAGENCY DVORAK ESTIMATES OF T2.5 (35 KTS) FROM PGTW AND RJTD AND 
BELOW THE MOST RECENT SATCON ESTIMATE OF 45 KNOTS. ENVIRONMENTAL 
ANALYSIS SHOWS THAT THE SYSTEM HAS A STRONG EQUATORWARD OUTFLOW 
CHANNEL, IS IN AN AREA OF LOW (10-15 KNOTS) VERTICAL WIND SHEAR 
(VWS), AND IS TRACKING THROUGH WARM (31 CELSIUS) SEA SURFACE 
TEMPERATURES. TS PAKHAR IS CURRENTLY TRACKING WEST-SOUTHWEST ALONG 
THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) 
CENTERED NEAR SOUTHERN JAPAN.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TS 16W WILL BEGIN TO TRACK NORTHWESTWARD PRIOR TO TAU 12, 
TRACKING TOWARDS A BREAK IN THE STR. PAKHAR WILL MAKE LANDFALL OVER 
LUZON SHORTLY AFTER TAU 12, TRACK NORTHWEST ACROSS LUZON AND EXIT 
INTO THE SOUTH CHINA SEA PRIOR TO TAU 24. THE SYSTEM WILL CONTINUE 
TO TRACK NORTHWEST ACROSS THE SOUTH CHINA SEA AND AGAIN MAKE 
LANDFALL TO THE SOUTHWEST OF HONG KONG PRIOR TO TAU 72. FAVORABLE 
ENVIRONMENTAL CONDITIONS WILL PROMOTE INTENSIFICATION UP TO A PEAK 
OF 50 KNOTS PRIOR TO LANDFALL OVER LUZON. INTERACTION WITH THE 
TERRAIN OF LUZON WILL WEAKEN THE SYSTEM DOWN TO 40 KNOTS 
PRIOR TO EXITING INTO THE SOUTH CHINA SEA. ONCE IN THE SOUTH CHINA 
SEA, PERSISTENT FAVORABLE CONDITIONS WILL PROMOTE RE-INTENSIFICATION 
WITH THE SYSTEM REACHING A PEAK INTENSITY OF 75 KNOTS PRIOR TO 
LANDFALL OVER CHINA. DYNAMIC MODEL GUIDANCE HAS SUGGESTED AN 
IMMEDIATE TURN TO THE NORTHWEST FOR THE PAST THREE MODEL RUNS, 
HOWEVER, THE SYSTEM HAS CONTINUED TO TRACK TO THE WEST-SOUTHWEST AS 
THE STR HAS NOT WEAKENED AS QUICKLY AS THE MODELS PROJECTED. ASIDE 
FROM THE TIMING OF THE TURN, THE MODEL GUIDANCE IS IN STRONG 
AGREEMENT ON THE NORTHWEST FORECAST TRACK BUT THE SYSTEMS CONTINUED 
MOTION TO THE WEST-SOUTHWEST LENDS LOW CONFIDENCE IN THIS PORTION OF 
THE JTWC TRACK FORECAST.  
   C. AT TAU 72, TS 16W WILL CONTINUE TO TRACK TO THE WEST ACROSS 
SOUTHERN CHINA AND INTO VIETNAM. AS THE SYSTEM IS MAKING LANDFALL, 
THE STR WILL RE-BUILD AND CAUSE THE SYSTEM TO TRACK MORE WESTERLY BY 
TAU 96, AND THEN TO THE WEST-SOUTHWEST BY THE END OF THE FORECAST 
PERIOD. TS PAKHAR WILL RAPIDLY WEAKEN AFTER LANDFALL DUE TO 
FRICTIONAL EFFECTS OF THE RUGGED TERRAIN OF SOUTHEAST CHINA, 
COMPLETELY DISSIPATING THE SYSTEM BY TAU 120. AVAILABLE DYNAMIC 
MODEL GUIDANCE BEGINS TO DIVERGE ON THE TRACK DIRECTION AS THE 
SYSTEM APPROACHES LAND AND CONTINUES TO SPREAD AFTER LANDFALL. THE 
DIFFERENCE IN MODEL TRACKS LENDS LOW CONFIDENCE IN THIS PORTION OF 
THE JTWC TRACK FORECAST.//
NNNN