WDPN31 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W (TWENTYFIVE) 
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.5N 139.3E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 157 NM NORTH OF ULITHI
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 10 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS FORMATIVE
CONVECTIVE BANDING OVER A PARTIALLY EXPOSED LOW LEVEL CIRCULATION 
CENTER WITH THE OVERALL PROGRESSION OF THE CONVECTIVE STRUCTURE OF
TD 25W REMAINING STAGNANT OVER THE PAST SIX HOURS. THE INITIAL
POSITION AND INTENSITY OF TD 25W IS BASED ON THE PGTW POSITION FIX
AND DVORAK CURRENT INTENSITY ESTIMATE OF 2.0 (30 KTS).

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A LOW TO MID-LEVEL
SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS
   CIMSS ADT: 32 KTS AT 240540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL DEPRESSION 25W IS FORECAST TO TRACK
GENERALLY NORTH NORTHWESTWARD FOR THE NEXT 48 HOURS UNDER THE
INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTHEAST. AFTER
TAU 48, THE SYSTEM WILL BEGIN TO ROUND THE SUBTROPICAL RIDGE AXIS
WHILE TURNING NORTH-NORTHEASTWARD. IT WILL CONTINUE THIS DIRECTION
FOR THE REMAINDER OF THE FORECAST AND BEGIN TO ACCELERATE IN TRACK
SPEED AROUND TAU 96 IN THE WAKE OF A MID-LATITUDE LOW. TD 25W WILL
REMAIN IN A FAVORABLE ENVIRONMENT FOR THE EARLY PORTION OF THE
FORECAST WHICH WILL ALLOW IT TO INTENSIFY TO A PEAK INTENSITY OF 80
KTS BY TAU 96. AFTERWARDS, THE SYSTEM WILL BEGIN TO ENCOUNTER
COOLING SEA SURFACE TEMPERATURES AND INCREASING VERTICAL WIND SHEAR
FROM THE MID-LATITUDE WESTERLIES, WEAKENING THE INTENSITY TO 70 BY
TAU 120. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN MODERATE AGREEMENT
IN REGARDS TO THE FORECAST TRACK FOR TD 25W, WITH ALL MODELS
SHOWING A GENERALLY NORTHWARD TRACK FOLLOWED BY A RECURVE TO THE
NORTHEAST. CROSS-TRACK MODEL SPREAD IS 160 NM AT TAU 72 AND FURTHER
INCREASES AT LATER TAUS AS NVGM OUTLIES TO THE WEST OF THE OTHER
MODELS. FOR THIS REASON, THE MODEL FORECAST IS PLACED SLIGHTLY EAST
OF THE MODEL CONSENSUS. NUMERICAL MODEL GUIDANCE IS ALSO IN
MODERATE AGREEMENT IN REGARDS TO THE INTENSITY FORECAST, WITH ALL
MODELS SHOWING STEADY INTENSIFICATION LEADING TO A PEAK INTENSITY
AROUND TAU 96 AND FOLLOWED BY A WEAKENING TREND FOR THE REMAINDER
OF THE FORECAST. THE MODELS CURRENTLY DO NOT AGREE ON THE PEAK
INTENSITY WITH DSHN PEAKING AT 130 KTS AND COTI PEAKING AT 65 KTS,
WITH MOST OTHERS AROUND 70-90 KTS. TO OFFSET DSHN, THE FORECAST
INTENSITY IS PLACED SLIGHTLY LOWER THAN CONSENSUS.

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