Tropical Storm SARIKA Advisory Ter, 18-10

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (SARIKA) WARNING NR 23//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 24W (SARIKA), LOCATED APPROXIMATELY 217 NM NORTHEAST OF
DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 09 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A RAPIDLY WEAKENING SYSTEM ABOUT TO MAKE LANDFALL NEAR
HAINAN. THE INITIAL POSITION IS BASED ON SATELLITE FIXES FROM PGTW
AND RJTD WITH FAIR CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT
70 KNOTS AND IS BASED ON THE WEAKENING CONVECTIVE STRUCTURE DUE TO
THE RECENT LAND INTERACTION COMBINED WITH RECENT DVORAK ESTIMATES
RANGING FROM T3.5 TO T4.5 (55 TO 77 KNOTS). UPPER-LEVEL ANALYSIS
SHOWS GOOD RADIAL OUTFLOW TAPPING INTO A PASSING SHORTWAVE TROUGH TO
THE NORTHWEST AND DOMINANT EASTERLY FLOW ON THE EQUATORWARD SIDE.
CURRENTLY TY SARIKA IS TRACKING NORTHWEST ALONG THE PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE TO THE NORTHEAST.3. FORECAST
REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING BULLETIN.
   B. TY SARIKA WILL CONTINUE TO TRACK NORTHWEST GUIDED BY THE
CURRENT STEERING RIDGE AS IT MAKES LANDFALL OVER HAINAN AND WEAKENS
SIGNIFICANTLY OVER THE NEXT 12 HOURS. THE TRACK WILL CONTINUE OVER
THE GULF OF TONKIN MAINTAINING TROPICAL STORM STRENGTH BEFORE MAKING
LANDFALL NEAR THE VIETNAM-CHINA BORDER, THEN TURN NORTHWARD AS
IT ROUNDS THE STEERING RIDGE AXIS. AVAILABLE MODEL GUIDANCE IS IN
VERY GOOD AGREEMENT AS THE SYSTEM TRACKS OVER HAINAN AND INTO
VIETNAM, BUT STARTS TO DIVERGE AS IT TRACKS FURTHER INLAND ROUNDING
THE RIDGE AXIS. OVERALL THERE IS HIGH CONFIDENCE IN THE FORECAST
TRACK.//
NNNN
NNNN