Tropical Storm KONG-REY Advisory 10月4日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 30W (KONG-REY) WARNING NR 24//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 30W (KONG-REY), LOCATED APPROXIMATELY 247 NM SOUTH OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
SHOWS THE SYSTEM CONTINUED TO WEAKEN AS CENTRAL CONVECTIVE TOPS
WARMED UP AND FEEDER BANDS UNRAVELED. THE PINHOLE EYE HAS BECOME
CLOUD-COVERED BUT STILL DISCERNIBLE. THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE BASED ON THE CLOUD-FILLED EYE THAT LINED UP WELL
WITH A MICROWAVE EYE FEATURE IN THE 031724Z ATMS IMAGE. THE INITIAL
INTENSITY OF 90 KNOTS IS BASED ON EQUIVALENT DVORAK ESTIMATES OF T5.0
FROM PGTW AND RJTD AND IS REFLECTIVE OF THE WEAKENING TREND. UPPER
LEVEL ANALYSIS INDICATES TY 30W IS STILL IN AN AREA OF LOW (05-10
KNOT) VERTICAL WIND SHEAR (VWS) AND EXCELLENT DUAL OUTFLOW CHANNELS
WITH A VERY STRONG POLEWARD BIAS. ALONG TRACK SEA SURFACE
TEMPERATURES (SSTS) REMAIN WARM AT (28-29 CELSIUS). HOWEVER, THE
CYCLONE IS NOW TRACKING ALONG A SWATH OF LOW OCEAN HEAT CONTENT
CAUSED BY THE PREVIOUS PASSAGE OF TY TRAMI SEVERAL DAYS AGO. PLUS,
COLD DRY AIR IS NOW ADVECTING FROM THE NORTHWEST. THESE SURFACE
DYNAMICS ARE THE PRIMARY CAUSES FOR THE SIGNIFICANT WEAKENING OF THE
SYSTEM. THE CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF
THE DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TY 30W WILL ROUND THE WESTERN EDGE OF THE STR AND TURN MORE
POLEWARD, CRESTING THE RIDGE AXIS NEAR TAU 36. AFTERWARD, IT WILL
RECURVE AND ACCELERATE NORTHEASTWARD AHEAD OF THE MID-LATITUDE TROUGH
  APPROACHING FROM THE NORTHWEST. BY TAU 72, TY 30W WILL BE IN THE
MIDDLE OF THE SEA OF JAPAN (SOJ). NEAR TAU 36, THE SYSTEM WILL BEGIN
EXTRA TROPICAL TRANSITION AND BY TAU 48 WILL BECOME A COLD-CORE LOW
OVER THE COLD WATERS OF THE SOJ. INCREASING VWS AND DECREASING SSTS
WILL CONTRIBUTE TO THE WEAKENING TREND DOWN TO 65 KNOTS BY TAU 72.
   C. AFTER TAU 72, TY KONG-REY WILL CONTINUE TO ACCELERATE
NORTHEASTWARD AND BY TAU 96, AT A TRACK SPEED EXCEEDING 30 KNOTS,
WILL HAVE CROSSED NORTHERN JAPAN AND EMERGED BACK IN THE PACIFIC
OCEAN EAST OF HOKKAIDO AS A STORM-FORCE 45-KNOT COLD CORE LOW, FULLY
EMBEDDED IN THE BAROCLINIC ZONE WITH AN EXPANSIVE WIND FIELD. DYNAMIC
MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A SMALL ACROSS-TRACK SPREAD;
HOWEVER, THERE IS POOR AGREEMENT IN THE ALONG-TRACK FORECAST SPEEDS
AFTER TAU 36. THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC
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