Tropical Storm CHAN-HOM Advisory Sat Jul 11

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (CHAN-HOM) WARNING NR 45//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 09W (CHAN-HOM), LOCATED APPROXIMATELY 386 NM SOUTH-
SOUTHWEST OF KUNSAN AB, HAS TRACKED NORTH-NORTHEASTWARD AT 09
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENCHANED INFARED IMAGERY
SHOWS A SLIGHT WEAKENING OF THE SYSTEM WITH A SMALL CLOUD FILLED EYE
WITH SOME EROSION ON THE WESTERN SIDE DUE TO LAND INTERACTION. THE
INTENSITY HAS BEEN BROUGHT DOWN SLIGHTLY TO 80 KNOTS BASED ON DVORAK
ESTIMATES FROM PGTW AND KNES. UPPER-LEVEL ANALYSIS INDICATES THE
SYSTEM IS IN AN AREA OF MODERATE (10-20 KNOTS) VWS WHICH IS OFFSET
BY VERY GOOD DUAL CHANNEL OUTFLOW. THE CYCLONE IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF THE DEEP-LAYERED STR.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. AS TY CHANG-HOM CONTINUES TO TRACK TO THE NORTHEAST AROUND THE
STR AXIS, EXPECT THE SYSTEM TO PICK UP SPEED AND DECAY. THE SYSTEM
WILL SLOWLY DECREASE IN INTENSITY DUE TO SOME IN-PHASE VWS AND LOW
OHC VALUES. ADDITIONALLY, PAST TAU 24, LAND INTERACTION WITH THE
MOUNTAINOUS KOREAN PENINSULA WILL RAPIDLY DECAY THE SYSTEM. THE
REMAINING STRUCTURE OF TY 09W WILL TRACK OVER THE COOLER WATERS OF
THE SEA OF JAPAN AND COMPLETELY DISSIPATE OVER LAND BY TAU 48 EAST
OF VLADIVOSTOK. AN ALTERNATE SCENARIO IS THAT TY 09W WILL BEGIN TO
INTERACT WITH A MID-LATITUDE TROUGH BY TAU 36 AND BEGIN ETT WITH
COMPLETE ETT BY TAU 48. DYNAMIC MODELS HANDLE HOW THE SYSTEM
DISSIPATES OR BECOME EXTRATROPICAL DIFFERENTLY WITH EUROPEAN AND
JAPANESE MODELS FAVORING DISSIPATION AND AMERICAN MODEL DEPICTING
ETT. AS SUCH, THERE REMAINS LOW CONFIDENCE IN THE JTWC FORECAST
TRACK.//
NNNN
NNNN