WDPN31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (TRAMI) WARNING NR 
013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.9N 122.9E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 176 NM NORTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
MARGINALLY FAVORABLE ENVIRONMENTAL CONDITIONS CONTINUE TO HINDER THE 
DEVELOPMENT OF TROPICAL STORM (TS) 22W. UPPER-LEVEL ANALYSIS DEPICTS A 
POINT SOURCE EAST OF THE SYSTEM CENTER, WHICH IS PRODUCING VIGOROUS 
WESTWARD OUTFLOW AND PERSISTENT DEEP CONVECTION OVER THE WESTERN 
QUADRANT. HOWEVER, A BROAD UPPER-LEVEL TROUGH OVER THE NORTHEASTERN 
QUADRANT AND THE ASSOCIATED CONVERGENCE IS SUPPRESSING CONVECTIVE 
DEVELOPMENT. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS DEEP 
CONVECTION BUILDING OVER THE SOUTHWESTERN QUADRANT OF A BROAD, 
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION (LLC). A 231003Z SSMIS 91GHZ 
COLOR COMPOSITE MICROWAVE IMAGE SUPPORTS THE INITIAL POSITION WITH 
HIGH CONFIDENCE AND SHOWS CONVECTIVE BANDING PRIMARILY OVER THE 
SOUTHERN SEMICIRCLE WRAPPING INTO THE SOUTHERN QUADRANT OF THE DEFINED 
LOW-LEVEL CIRCULATION CENTER. A 231000Z RCM-3 SAR IMAGE SHOWS A VERY 
BROAD CORE OF WEAK WINDS WITH UNREALISTICALLY HIGH MAXIMUM WINDS OF 
60-65 KNOTS. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH HIGH 
CONFIDENCE BASED ON CONCURRENT DVORAK CURRENT INTENSITY ESTIMATES OF 
T3.0 (45 KNOTS) FROM ALL AGENCIES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.0 - 45 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS SATCON: 54 KTS AT 231017Z
   CIMSS ADT: 41 KTS AT 231130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE WESTWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 22W IS FORECAST TO TRACK
WEST-NORTHWESTWARD THROUGH TAU 12 ALONG THE SOUTHWESTERN PERIPHERY
OF THE STR, TOWARD A BREAK IN THE STR PRODUCED BY A MIDLATITUDE
SHORTWAVE TROUGH DIGGING INTO THE EAST CHINA SEA. AFTER TAU 12,
THE STR WILL REBUILD TO THE NORTH TURNING THE SYSTEM ONTO A MORE
WESTWARD TRAJECTORY. THE SYSTEM WILL MAKE LANDFALL NEAR TAU 03,
WITH SIGNIFICANT WEAKENING COMMENCING. AFTER TAU 12, TS 22W WILL
WEAKEN AND DECOUPLE WHILE CROSSING THE RUGGED TERRAIN OF LUZON,
WITH A LIKELY LEESIDE JUMP. THIS WILL RESULT IN AN APPARENT DIP IN
THE FORECAST TRACK AS A NEW PRESSURE CENTER FORMS AND STRENGTHENS
OFF THE WEST COAST OF LUZON NEAR TAU 24. AFTER TAU 36, THE SYSTEM
WILL RESUME A WESTWARD TRACK UNDER THE STR TO THE NORTH WITH
STEADY INTENSIFICATION TO ABOUT 60 KNOTS BY TAU 72. AFTER TAU 72, TS 
22W WILL SLOW AND STALL AS A SUBTROPICAL RIDGE BUILDS TO THE WEST OF
THE SYSTEM INDUCED BY THE DEVELOPING TROPICAL CYCLONE IN THE BAY
OF BENGAL (TC 03B).      

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT THROUGH TAU 72, WITH A 80NM TO 85NM CROSS-TRACK SPREAD
FROM TAU 48 TO TAU 72. AFTER TAU 72, THE GUIDANCE DIVERGES
SIGNIFICANTLY WITH MANY MODELS INDICATING A QUASISTATIONARY TRACK
MOTION AND STALL EAST OF VIETNAM. GFS HAS SHIFTED ITS TRACK JUST OFF 
THE COAST OF CENTRAL VIETNAM BUT STILL DISSIPATES THE SYSTEM BY TAU 
120. THE 230000Z ECMWF ENSEMBLE (EPS) AND THE 230600Z GFS ENSEMBLE 
(GEFS) SHOW THE LARGE MAJORITY OF SOLUTIONS STALLING EAST OF VIETNAM 
WHILE MAINTAINING A MINIMAL TROPICAL STORM STRENGTH SYSTEM. RELIABLE 
INTENSITY GUIDANCE SHOWS A PEAK INTENSITY NEAR TAU 60-72 RANGING FROM 
49 KNOTS (HAFS-A) TO AS HIGH AS 83 KNOTS (HWRF). THE JTWC INTENSITY 
FORECAST REMAINS HIGHLY CONSISTENT WITH PREVIOUS WARNINGS SHOWING A 
PEAK INTENSITY OF 60 KNOTS, HEDGED JUST HIGHER THAN THE INTENSITY 
CONSENSUS (ICNW) PEAK OF 51 KNOTS. 

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