WDPN31 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KAMMURI) WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS. 
   TYPHOON 29W (KAMMURI), LOCATED APPROXIMATELY 1014 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS A BROAD SYSTEM WITH CENTRAL DENSE OVERCAST OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE BASED ON BANDING SEEN IN A 281134Z AMSU MICROWAVE IMAGE WITH CONVECTION SHEARED TO THE SOUTHWEST OF THE LLCC. THE INITIAL INTENSITY OF 75 KNOTS IS HEDGED ON THE LOW SIDE OF DVORAK CURRENT ESTIMATES OF T4.5-5.0 (77-90 KNOTS) FROM RJTD AND PGTW AS WELL AS A 281006Z SATCON ESTIMATE OF 68 KNOTS. ANALYSIS INDICATES AN OVERALL FAVORABLE ENVIRONMENT WITH SLIGHTLY OFFSET WESTWARD AND POLEWARD OUTFLOW, LOW TO MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR, AND VERY WARM (30 DEGREES CELSIUS) ALONG-TRACK SEA SURFACE TEMPERATURE. THE CYCLONE IS TRACKING IN THE PHILIPPINE SEA ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE EAST. 
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE.
   B. TY 29W WILL CONTINUE TO TRACK NORTH-NORTHWESTWARD INTO A COL UNTIL BECOMING QUASI-STATIONARY AROUND TAU 12. AFTERWARDS, A NEWLY-FORMED STR TO THE NORTHWEST WILL BUILD, REORIENT, AND SLOWLY DRIVE THE SYSTEM WESTWARD. LIKELY, THE OVERALL FAVORABLE ENVIRONMENT WILL CONTINUE TO FUEL INTENSIFICATION TO 125 KNOTS BY TAU 72. MODEL GUIDANCE HAS CONTINUED TO IMPROVE FOR THIS PORTION OF THE FORECAST AS GLOBEL MODELS HAVE CONVERGED ON A WESTWARD TRACK. THERE IS OVERALL GOOD TRACK CONFIDENCE. HOWEVER, DUE TO UNCERTAINTY IN THE ENVIRONMENTAL CONDITIONS FROM MODERATE SHEAR AND POSSIBLY DIMINISHING UPPER LEVEL SUPPORT, THERE IS LOW CONFIDENCE IN THE INTENSITY FORECAST.
   C. AFTER TAU 72, TY KAMMURI WILL CONTINUE ON A WESTWARD TRACK UNDER THE SECONDARY STR AND OVER THE VERY WARM PHILIPPINE SEA BEFORE MAKING LANDFALL EAST OF MANILA, PHILIPPINES AROUN TAU 120. MODERATE SHEAR, DRY AIR AND CONVERGENCE ALOFT ARE POSSIBLE CONTRIBUTORS TO DECREASED INTENSITY AFTER TAU 96. TY 29W WILL BE FURTHER HAMPERED BY FRICTIONAL EFFECTS DUE TO LAND INTERACTION AROUND TAU 120. NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT WITH THE CURRENT FORECAST TRACK. HOWEVER, NAVGEM STILL DEPICTS AN EARLY RECURVE TO THE NORTH AFTER TAU 96. DESPITE THIS OUTLIER, THERE IS ONLY A 170 NM TRACK SPREAD AT TAU 120. GIVEN THE STORM MOTION UNCERTAINTY IN THE COL, THERE IS OVERALL FAIR CONFIDENCE TO THE JTWC TRACK FORECAST IN THE LATER TAUS.//
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