WDPN32 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR 
044//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 27.8N 131.1E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 326 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 34 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 06W (KHANUN) REMAINS QUITE LARGE, WITH THE
INNER CORE BECOMING INCREASINGLY DISORGANIZED AS MULTIPLE VORTICES
ARE SPINNING AROUND THE INNER-EDGE OF THE DONUT-LIKE BAND OF
CONVECTION SITUATED ABOUT 85 NM OUT FROM THE ASSESSED CENTER. THE
LOW-LEVEL STRUCTURE IS MUCH IMPROVED BASED ON AN ANALYSIS OF A
062159Z SSMIS 37GHZ MICROWAVE IMAGE, WHICH SHOWED WELL-DEFINED
LOW-LEVEL BANDING FEATURES SURROUNDING THE LARGE CORE LOW
EMISSIVITY REGION. THE MSI DEPICTS DEEP CONVECTION IS FLARING
ACROSS ALL QUADRANTS EXCEPT FOR THE NORTHEAST, WHERE SOME MID-LEVEL
DRY AIR CONTINUES TO LINGER. ANIMATED MSI AND WATER VAPOR IMAGERY
SHOWS RADIAL OUTFLOW CONTINUES TO EXPAND OUTWARD BUT REMAINS
RELATIVELY CONFINED AND IS NOT YET CONNECTING TO ANY OUTFLOW
CHANNELS. THE INITIAL POSITION IS PLACED IN A CENTROID POSITION,
CONSCIOUSLY NOT FOLLOWING ANY OF THE PERIPHERAL VORTICIES. THE
INITIAL INTENSITY REMAINS SET AT 55 KNOTS, SET ON THE HIGHER END OF
THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES, AND CONSISTENT WITH
EARLIER SAR AND AMSR2 MEASUREMENTS. WHILE THE SYSTEM IS NOT MOVING
VERY QUICKLY, IT IS LEAVING THE REGION OF UPWELLING IN ITS WAKE,
AND MOVING INTO DEEPER, WARMER WATERS. COMBINED WITH THE STEADILY
IMPROVING OUTFLOW AND MOISTENING OF THE AIRMASS DOWN TRACK, THE
BOTTOM LINE IS THAT THE ENVIRONMENT IS STEADILY IMPROVING.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WEAK STEERING PATTERN. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T3.0 - 45 KTS
   CIMSS ADT: 33 KTS AT 062040Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: INDEPENDENT OF THE MESO-VORTICES RIDING AROUND
THE EASTERN PERIPHERY OF THE CIRCULATION, THE CENTROID OF THE
SYSTEM HAS LIKELY REACHED ITS EASTERN-MOST POINT AS IT IS RUNNING
FACE-FIRST INTO A BUILDING RIDGE EXTENDING TO THE NORTH ALONG THE
14O3 LONGITUDE LINE. THE SYSTEM IS EXPECTED TO MAKE A GRADUAL TURN
TO THE NORTH OVER THE NEXT FEW HOURS AS THE RIDGE CONTINUES TO
EXTEND TO THE NORTH. AFTER TAU 24, THE STRONG SUBTROPICAL RIDGE
(STR) TO THE NORTHEAST BUILDS IN AND ASSUMES THE DOMINANT STEERING
ROLE, PUSHING TS 06W ONTO A MORE NORTH-NORTHWEST TRACK, WHICH IS
EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE FORECAST PERIOD.
THE SYSTEM IS FORECAST TO PASS WEST OF KYUSHU PASSING THROUGH THE
GOTO ISLANDS, ON ITS WAY TOWARDS EVENTUAL LANDFALL IN KOREA. EVEN
THOUGH THE ENVIRONMENT CONTINUES TO IMPROVE, THE LACK OF A STRONG
OUTFLOW CHANNEL AND THE BROAD NATURE OF THE SYSTEM WILL CONTINUE TO
SLOW THE PACE OF INTENSIFICATION THROUGH THE FIRST 48 HOURS OF THE
FORECAST. ONCE THE SYSTEM REACHES SOUTHERN KYUSHU, IT WILL BEGIN TO
TAP INTO THE RIGHT ENTRANCE REGION OF A 200MB JET MAX OVER FAR
NORTHEASTERN CHINA, WHICH WILL KICK THE SYSTEM INTO HIGH GEAR,
UNLEASHING A MORE RAPID PACE OF INTENSIFICATION. THE CURRENT
FORECAST CALLS FOR A PEAK OF 70 KNOTS, THOUGH A SLIGHTLY HIGHER
PEAK IS POSSIBLE, DEPENDING ON HOW FAR WEST OF KYUSHU THE SYSTEM
PASSES, AND THE WIDTH OF THE RADIUS OF MAXIMUM WINDS (RMW) AT THAT
TIME. THE SYSTEM IS FORECAST TO MAKE LANDFALL ALONG THE SOUTHERN
COAST OF KOREA TO THE WEST OF BUSAN AROUND TAU 72. AFTER LANDFALL,
THE SYSTEM WILL TRACK NORTHWARD THROUGH THE CENTER OF THE KOREAN
PENINSULA WHILE RAPIDLY WEAKENING DUE TO THE EFFECTS OF THE RUGGED
TERRAIN OF THE KOREA PENINSULA AND INCREASING SHEAR, ULTIMATELY
DISSIPATING BY TAU 120 OVER NORTHEASTERN CHINA.

MODEL DISCUSSION: TRACK GUIDANCE HAS COME INTO BETTER AGREEMENT
WITH THIS RUN, WITH THE NAVGEM NOW JOINING THE REST OF THE
CONSENSUS PACK. THE UKMET AND UKMET ENSEMBLE ON THE OTHER HAND,
STUBBORNLY PERSIST IN TRACKING THE SYSTEM OVER THE YELLOW SEA AND
INTO THE BOHAI GULF. THE REMAINDER OF THE GUIDANCE PACKAGE IS
CONFINED TO A TRACK ENVELOPE, WHICH IS BASICALLY CONFINED TO THE
WIDTH OF THE KOREAN PENINSULA. THE JTWC FORECAST REMAINS CONSISTENT
WITH THE PREVIOUS FORECAST AND LIES ON THE EASTERN EDGE OF THE
GUIDANCE THROUGH THE BULK OF THE FORECAST PERIOD. CONFIDENCE IS
MEDIUM, PRIMARILY IN LIGHT OF THE UNCERTAINTY IN THE INITIAL
POSITION AND TROCHOIDAL MOTION ANTICIPATED THROUGH THE FIRST 12 TO
24 HOURS OF THE FORECAST. INTENSITY GUIDANCE IS IN GOOD AGREEMENT
WITH THE OVERALL INTENSITY SCENARIO, WITH THE HAFS-A, AND GFS
PEAKING THE SYSTEM AT 70 KNOTS WHILE THE CONSENSUS PEAK IS ABOUT
FIVE KNOTS LOWER. OVERALL CONFIDENCE IN THE INTENSITY FORECAST IS
MEDIUM TO HIGH. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: HIGH//
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