Tropical Storm KAMMURI Advisory Sáb, 30-11

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KAMMURI) WARNING NR 019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 29W (KAMMURI), LOCATED APPROXIMATELY 834 NM EAST
OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY REVEALS A CONSOLIDATING SYSTEM WITH IMPROVED SPIRAL BANDING
WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 300557Z SSMI
37GHZ IMAGE THAT FURTHER DEPICTS BANDING AND CONVECTION TO THE NORTH
AND WEST OF AN APPARENT MICROWAVE EYE FEATURE. THE 85GHZ IMAGE FROM
THIS PASS DEPICTS AN UPPER LEVEL CENTER OFFSET 44NM TO THE WEST-
SOUTHWEST OF THE LLCC DUE TO NORTHEASTERLY VERTICAL WIND SHEAR
(VWS). THIS, ALONG WITH AN OBLONG CIRCULATION IN AN EARLIER 300102Z
ASCAT-B IMAGE, SUGGESTS THE SYSTEM IS STRUGGLING TO CONSOLIDATE DUE
TO PERSISTENT VWS. THE INITIAL INTENSITY ESTIMATE OF 70KTS IS HEDGED
WITH FAIR CONFIDENCE SLIGHTLY LOWER THAN A PGTW DVORAK CURRENT
INTENSITY ESTIMATE OF 4.5 (77KTS) BASED ON THE STRUCTURE OF THE
SYSTEM. TY 29W IS CURRENTLY TRACKING ALONG THE SOUTHEASTERN
PERIPHERY OF AN EXTENSION OF THE SUBTROPICAL RIDGE (STR) TO THE
NORTH AND IS IN A 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 WEST 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 105KTS 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 FORECASTS 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
GENERALLY WEST-SOUTHWEST 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.//
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