WDPN31 PGTW 241500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W (TWENTYFIVE) 
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.4N 139.7E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 210 NM NORTH OF ULITHI
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
FORMATIVE BANDING WITH POCKETS OF DEEP SUSTAINED CONVECTION TO THE
NORTHEAST AND WEST OF THE CIRCULATION CENTER. A PARTIAL 240954Z
ASCAT-A IMAGE DEPICTS HALF OF AN ELONGATED CIRCULATION WITH AN AREA
OF 25-30 KNOTS WINDS EAST OF THE BROAD CENTER. THE INITIAL POSITION
IS BASED ON THE PGTW POSITION FIX AND THE INITIAL INTENSITY IS
BASED ON THE ASCAT-A IMAGE AND THE PGTW DVORAK 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 BUILDING
SUBTROPICAL RIDGE 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: 35 KTS AT 241140Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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
EVENTUALLY 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 KTS
BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT IN
REGARDS TO THE FORECAST TRACK FOR TD 25W, WITH ALMOST ALL MODELS
SHOWING A GENERALLY NORTH-NORTHWESTWARD TRACK FOLLOWED BY A RECURVE
TO THE NORTHEAST AFTER TAU 72. THE EXCEPTION IS NVGM WHICH GREATLY
DEVIATES WESTWARD AT TAU 36. EXCLUDING NVGM, CROSS-TRACK MODEL
SPREAD IS LESS THAN 100 NM ALL THE WAY UP TO TAU 120. NUMERICAL
MODEL GUIDANCE IS IN MODERATE AGREEMENT IN REGARDS TO THE INTENSITY
FORECAST, WITH MOST MODELS SHOWING STEADY INTENSIFICATION LEADING
TO A PEAK INTENSITY AROUND TAU 96, 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 110 KTS AND COTI
PEAKING AT 60 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: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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