WDPN31 PGTW 120300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 29W (NAKRI) WARNING NR 
016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 30.1N 133.5E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 262 NM SOUTH-SOUTHEAST OF IWAKUNI, JAPAN
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 17 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP
CONVECTION BUILDING AND OBSCURING THE LOW-LEVEL CIRCULATION CENTER
(LLCC) OF TROPICAL STORM (TS) 29W. THE DEEP CONVECTIVE BANDING IS
STRONGEST ALONG THE SOUTHERN AND EASTERN PERIPHERY AS WELL. OUTFLOW
IS STRONG AND POLEWARD, ENHANCED BY THE SUBTROPICAL JET TO THE
NORTH. CONTINENTAL DRY AIR CONTINUES TO FLANK THE WESTERN PERIPHERY
OF TS 29W, HOWEVER, THE CORE REMAINS MOIST AND FUELED BY THE WARM
WATERS OF THE KUROSHIO CURRENT. THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON THE OBSCURED LLCC IN ANIMATED MSI. THE 
INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH LOW
CONFIDENCE BASED ON PERSISTENCE AND THE AGENCY FIXES BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: A SUBTROPICAL RIDGE TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RCTP: T3.5 - 55 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 29W WILL CONTINUE UNDER THE STEERING
INFLUENCE OF THE SUBTROPICAL RIDGE TO THE EAST. THE TRACK WILL
GRADUALLY SHIFT THROUGHOUT THE FORECAST AS THE SYSTEM CURVES ALONG
THE NORTHERN PERIPHERY OF THE RIDGE FROM A NORTHEASTERLY TRACK TO
AN EAST-NORTHEASTERLY TRACK. EARLY IN THE TRACK, THE SYSTEM WILL
REMAIN IN A FAVORABLE ENVIRONMENT OF WARM SEA SURFACE TEMPERATURES
ALONG THE KUROSHIO CURRENT, LOW VERTICAL WIND SHEAR, AND STRONG
UPPER-LEVEL DIVERGENCE. TS 29W WILL CONTINUE TO DEVELOP TO A PEAK
INTENSITY OF 80KTS BY TAU 36. AFTER TAU 36, THE CLOSE APPROACH OF
TS 29W WILL RESULT IN UNFAVORABLY HIGH VERTICAL WIND SHEAR,
STRAIGHT-LINE UPPER-LEVEL FLOW, AND COOL WATERS THAT THE SYSTEM
WILL BEGIN TO INTERACT WITH BETWEEN TAU 36-48. ADDITIONALLY, TS 29W
WILL LOSE CLASSIC TROPICAL CYCLONE QUALITIES AT TAU 48 AS THE
SYSTEM BEGINS TO DEVELOP FRONTS, BECOMES COLD-CORE, AND VERTICALLY
TILTED. BY THE END OF THE FORECAST PERIOD, TS 29 WILL HAVE 
TRANSITIONED TO A 45KT EXTRATROPICAL CYCLONE.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT TS 29W WILL CURVE ALONG THE NORTHERN PERIPHERY OF
THE SUBTROPICAL RIDGE OVER THE NEXT 72 HOURS. THE FORECAST
CONFIDENCE IS REINFORCED BY THE 90NM CROSS-TRACK SPREAD BY THE END
OF THE FORECAST PERIOD. THE INTENSITY GUIDANCE HAS COME INTO BETTER
AGREEMENT, WITH A SPREAD OF PEAK INTENSITIES BETWEEN 70-85KTS FROM
TAU 36-48.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: MEDIUM//
NNNN