Tropical Storm KROSA Advisory Fri Nov 01

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KROSA) WARNING NR 10//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 29W (KROSA), LOCATED APPROXIMATELY 234 NM NORTH-NORTHEAST
OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) INDICATES A TIGHTLY WRAPPED SYSTEM WITH CONVECTIVE BANDING
WRAPPING AROUND A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC)
AND A DEVELOPING EYE FEATURE. THE INITIAL POSITION IS BASED UPON
THIS WELL DEFINED LLCC SEEN IN THE MSI ANIMATION WITH GOOD
CONFIDENCE. THE INITIAL INTENSITY REMAINS ASSESSED AT 80 KNOTS BASED
ON DVORAK INTENSITY ESTIMATES OF 77 KNOTS FROM BOTH KNES AND PGTW
AND THE PERSISTENT STRUCTURE OF THE SYSTEM. UPPER-LEVEL ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH NEAR-RADIAL OUTFLOW AND LOW
(05-10 KNOTS) VERTICAL WIND SHEAR (VWS). TY 29W IS TRACKING WESTWARD
ALONG THE SOUTHWEST PERIPHERY OF THE SUBTROPICAL RIDGE (STR)
POSITIONED TO THE NORTHEAST OF THE SYSTEM AND IS STARTING TO
INTERACT WITH NORTHERN LUZON AS LANDFALL IS IMMINENT.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 29W IS FORECAST TO CONTINUE TO TRACK WEST-NORTHWESTWARD
ALONG THE SOUTHWESTERN PERIPHERY OF THE CURRENT STEERING STR THROUGH
TAU 36 AS THE SYSTEM SLIGHTLY WEAKENS DUE TO PASSAGE OVER NORTHERN
LUZON. AFTER WHICH, TY 29W WILL BEGIN TO RE-INTENSIFY AS IT MOVES
INTO THE MORE OPEN WATERS OF THE SOUTH CHINA SEA. AFTER TAU 36, TY
29W IS EXPECTED TO SLOW AS IT SWITCHES FROM ITS CURRENT STR TO
ANOTHER STR OVER CHINA. THE STR OVER CHINA WILL BE THE DOMINATE
STEERING FACTOR THROUGH THE REST OF THE FORECAST AS IT BEGINS TO
TRACK THE SYSTEM TO THE SOUTHWEST. AFTER TAU 48, A SLOW WEAKENING
TREND IS EXPECTED AS LAND INTERACTION WITH HAINAN ISLAND, COOLER
SSTS AND INCREASING VERTICAL WIND SHEAR WILL BEGIN TO ERODE THE
SYSTEM.
   C. IN THE EXTENDED TAUS, TY 29W WILL CONTINUE SOUTHWESTWARD UNDER
THE STEERING INFLUENCE OF THE STR OVER CHINA. CONTINUED WEAKENING IS
EXPECTED AS ENVIRONMENTAL CONDITIONS CONTINUE TO BECOME FURTHER
UNFAVORABLE AS THE SYSTEM MAKES LANDFALL INTO VIETNAM. DYNAMIC
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 48; HOWEVER, THERE
CONTINUES TO BE A LARGE VARIANCE IN SOLUTIONS AS THE SYSTEM SWITCHES
STEERING INFLUENCES FROM ITS CURRENT STR TO THE STR OVER CHINA. DUE
TO THIS, LOW OVERALL CONFIDENCE REMAINS IN THE FORECAST TRACK.//
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