WDPN33 PGTW 120300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 26W (TORAJI) WARNING NR 
012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.7N 118.7E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 279 NM NORTH-NORTHWEST OF MANILA,
PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 26W HAS WEAKENED SLIGHTLY DURING THE PAST SIX
HOURS WHILE TRACKING NORTHWESTWARD AWAY FROM LUZON OVER THE
NORTHERN PORTION OF THE SOUTH CHINA SEA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS FRAGMENTED CONVECTION ALONG THE
NORTHERN AND SOUTHWESTERN PERIPHERIES OF A PARTIALLY EXPOSED
LOW-LEVEL CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON RECENT MULTI-AGENCY SATELLITE FIXES AND
MSI. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON A CONSENSUS OF AVAILABLE SUBJECTIVE DVORAK AND
AUTOMATED INTENSITY ESTIMATES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP LAYER SUBTROPICAL RIDGE (STR) TO
THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.0 - 45 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS ADT: 47 KTS AT 112330Z
   CIMSS AIDT: 41 KTS AT 112330Z
   CIMSS D-PRINT: 37 KTS AT 112330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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 26W IS EXPECTED TO CONTINUE TRACKING
WEST-NORTHWESTWARD AND GRADUALLY TURN WESTWARD AFTER TAU 36 UNDER
THE CONTINUED STEERING INFLUENCE OF THE STR TO THE NORTH THROUGHOUT
THE FORECAST PERIOD. MODEST NEAR-TERM INTENSIFICATION IS POSSIBLE
DURING PASSAGE OVER VERY WARM WATER AND FAVORABLE POLEWARD
OUTFLOW ALOFT. HOWEVER, MID-LEVEL WESTERLY VERTICAL WIND SHEAR AND
ENTRAINMENT OF DRY AIR FROM THE SOUTH AND WEST IS EXPECTED TO
INCREASE SIGNIFICANTLY AROUND TAU 36 AND LEAD TO DISSIPATION BY TAU
72. AS THE SYSTEM DISSIPATES, THE STEERING LEVEL WILL DROP AND THE
REMNANT CIRCULATION IS EXPECTED TO MEANDER WITHIN A WEAK STEERING
ENVIRONMENT TO THE EAST OF HAINAN ISLAND.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING THE OVERALL TRACK AND INTENSITY FORECAST SCENARIOS, WITH
ALL MODELS DEPICTING A WEST-NORTHWESTWARD TRACK FOLLOWED BY
DISSIPATION AND SLOW FORWARD MOTION OF THE REMNANT CIRCULATION TO
THE EAST OF HAINAN. MODEL VORTEX TRACKERS DIVERGE SIGNIFICANTLY
AFTER TAU 48, WITH THE MOGREPS-G ENSEMBLE DEPICTING A SOUTHEASTWARD
TURN AND MOST OF THE REMAINING GUIDANCE TURNING THE CIRCULATION
SLOWLY TO THE SOUTH BEYOND THE FORECAST PERIOD. REGARDLESS OF THE
TRACK IN THE EXTENDED TERM, VERY LITTLE, IF ANY, SIGNATURE OF THE
CIRCULATION WILL REMAIN AS ALL GUIDANCE INDICATES AN EXTREMELY
UNFAVORABLE ENVIRONMENT.

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