WDPN32 PGTW 080300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR 
048//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 28.9N 130.9E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 259 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS DEEP
CONVECTIVE BANDS WRAPPING INTO A BROAD, EXPOSED CENTER WITH
MULTIPLE MESOVORTICES ROTATING CYCLONICALLY AROUND A CENTROID. THE
INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE
CENTROID ON THE MSI LOOP AND ALSO ON A COMPOSITE RADAR LOOP. THE
INITIAL INTENSITY IS ALSO PLACED WITH MEDIUM CONFIDENCE BASED ON
THE OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND
REFLECTS THE SLIGHT 6-HR WEAKENING. ANALYSIS INDICATES A MARGINAL
ENVIRONMENT WITH MODERATE EQUATORWARD OUTFLOW, LOW VWS, AND WARM
SST OFFSET BY SUBSIDENCE ALONG THE NORTHWEST SIDE AND DRY AIR
ENTRAINMENT IN THE LOW LEVELS.

INITIAL WIND RADII BASIS: PERSISTENCE. 

CURRENT STEERING MECHANISM: WEAK SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST. 


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   CIMSS SATCON: 43 KTS AT 072255Z
   CIMSS ADT: 32 KTS AT 072330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 06W IS EXPECTED TO SLOWLY DRIFT GENERALLY
NORTH-NORTHWESTWARD TOWARD SOUTH KOREA AS THE STEERING STR BUILDS,
MAKING LANDFALL WEST OF BUSAN AROUND TAU 48, TRACK JUST TO THE WEST
OF SEOUL AROUND TAU 66, BEFORE TURNING NORTHWARD INTO NORTH KOREA
THEN CROSS INTO NORTHEASTERN CHINA. THE ENVIRONMENT WILL SLIGHTLY
IMPROVE AS SST WARMS AROUND THE ISLAND OF KYUSHU, JAPAN, THEN WITH
INCREASING POLEWARD OUTFLOW, FUELING A SLIGHT INTENSIFICATION TO A
PEAK OF 55KTS AT TAUS 24-36. AFTERWARD, INTERACTION WITH THE KOREAN
PENINSULA WILL LEAD TO GRADUAL DETERIORATION TO 3OKTS NEAR SEOUL BY 
TAU 72 THEN TO EVENTUAL DISSIPATION BY TAU 120 AFTER THE SYSTEM
CROSSES INTO CHINA. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT UP
TO TAU 72 WITH AN EVEN SPREAD TO 130NM, LENDING HIGH CONFIDENCE TO
THIS PORTION OF THE JTWC TRACK FORECAST. AFTERWARD, THE MODELS
BECOME MORE SPREAD OUT AND ERRATIC, LENDING LOW CONFIDENCE IN THE
EXTENDED PORTION OF THE JTWC FORECAST. 

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