WDPN31 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KAMMURI) WARNING NR 020//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS. 
   TYPHOON (TY) 29W (KAMMURI), LOCATED APPROXIMATELY 762 NM EAST
OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 11 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY REVEALS RAPIDLY CYCLING CONVECTION AND DENSE CIRROSTRATUS 
OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL 
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 301208Z MHS 89GHZ 
COMPOSITE IMAGE THAT DEPICTS A SHALLOW, BROAD LLCC WITH DEEP 
CONVECTION CONFINED TO THE WEST QUADRANT. A 301209Z ASCAT-B IMAGE 
DEPICTS A WELL DEFINED CENTER WITH AN ISOLATED POCKET OF 50KT WINDS 
AND ALSO SUPPORTS THE PLACEMENT OF THE INITIAL POSITION. THE INITIAL 
INTENSITY ESTIMATE OF 65KTS IS BASED ON A PGTW DVORAK ESTIMATE OF 
T4.0/4.5 (65/77 KTS) AND THE AFOREMENTIONED ASCAT-B DATA. TY 29W IS 
CURRENTLY TRACKING ALONG THE SOUTHEASTERN PERIPHERY OF AN EXTENSION 
OF THE SUBTROPICAL RIDGE (STR) TO THE NORTH AND IS IN A MARGINALLY 
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW TO MODERATE (15-
20KTS) VWS OFFSET BY WARM (29C) SEA SURFACE TEMPERATURES, VERY HIGH 
OCEAN HEAT CONTENT VALUES AND ROBUST POLEWARD AND EQUATORWARD 
OUTFLOW ALOFT. 
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM 
THE LAST PROGNOSTIC REASONING MESSAGE.
   B. THROUGH TAU 36, TY 29W WILL CONTINUE TO TRACK WESTWARD ALONG 
THE SOUTHEASTERN PERIPHERY OF THE STR. AFTER TAU 36, A PASSING 
SHORTWAVE TROUGH TO THE NORTH WILL ERODE THE STR TO THE WEST OF TY 
29W, AND ALLOW A STR TO THE NORTHEAST TO STEER THE SYSTEM WESTWARD. 
THIS EROSION OF THE STR TO THE WEST WILL ALSO ALLOW FOR ENHANCED 
POLEWARD OUTFLOW ALLOWING THE SYSTEM TO INTENSIFY TO 100KTS BY TAU 
48. AFTER TAU 48 THE SYSTEM WILL BEGIN TO PASS OVER LUZON WHERE IT 
WILL BEGIN TO WEAKEN DUE TO THE FRICTIONAL EFFECTS OF LAND 
INTERACTION. POSSIBLE DRY AIR ENTRAINMENT FROM THE NORTHEAST SURGE 
MAY ALSO LEAD TO A FURTHER DECAY IN INTENSITY AT THIS TIME. THERE IS 
STRONG AGREEMENT IN MODEL TRACK GUIDANCE, LENDING HIGH CONFIDENCE TO 
THIS PORTION OF THE TRACK FORECAST, HOWEVER THERE IS SIGNIFICANT 
SPREAD IN INTENSITY GUIDANCE AND THUS THERE IS LOW CONFIDENCE IN THE 
INTENSITY FORECAST. 
   C. AFTER TAU 72, TY 29W WILL CONTINUE TO TRACK GENERALLY WESTWARD 
AND MOVE INTO THE SOUTH CHINA SEA. HERE, IT WILL BEGIN TO TRACK 
SOUTHWESTWARD AND WEAKEN SIGNIFICANTLY AS IT BEGINS TO 
INTERACT WITH A STRONG NORTHEAST SURGE EVENT. MODEL TRACK GUIDANCE 
REMAINS IN GOOD AGREEMENT THROUGH THE REMAINDER OF THE FORECAST THUS 
CONFIDENCE IN THIS PORTION OF THE FORECAST TRACK IS HIGH.//
NNNN