WDPN31 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (TRAMI) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.6N 127.4E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 377 NM EAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM 22W (TRAMI) AS IT CONTINUES DEVELOPING SPIRAL BANDS OF DEEP
CONVECTION WRAPPING INTO A PARTLY EXPOSED LOW-LEVEL CIRCULATION 
CENTER, JUST EAST OF LUZON, PHILIPPINES. FLARING CONVECTION AND 
STRONG
POLEWARD AND EQUATORWARD OUTFLOW ARE FUELING STEADY DEVELOPMENT AS 
THE
SYSTEM TRACKS NORTHWESTWARD. THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON THE PARTLY EXPOSED LLCC IN THE ANIMATED 
MSI, AS WELL AS AN ARC FEATURE IN THE 212123Z SSMIS 37 GHZ IMAGE. THE 
INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED 
ON THE OBJECTIVE AND AGENCY ESTIMATES LISTED BELOW AND REFLECTS THE 
MOSTLY SUSTAINED 6-HR CONVECTIVE AND WRAP SIGNATURES.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SOUTHWEST EXTENSION OF THE SUBTROPICAL
RIDGE (STR) TO THE NORTHEAST 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   CIMSS SATCON: 45 KTS AT 212139Z
   CIMSS ADT: 39 KTS AT 212330Z
   CIMSS DPRNT: 34 KTS AT 220000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   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 TRAMI WILL CONTINUE TRANSITING
NORTHWESTWARD OVER THE NEXT 36 HOURS UNDER THE INFLUENCE OF THE
STR EXTENSION TO THE NORTHEAST. AS THE SYSTEM APPROACHES LUZON,
ANOTHER STR TO THE NORTH WILL ASSUME THE STEERING AND LEAD TRAMI
WESTWARD INTO LUZON, WHILE THE SYSTEM REACHES 50 KTS PRIOR TO 
LANDFALL
IN THE PHILIPPINES. AS TS 22W MOVES WESTWARD ACROSS THE CORDILLERA
MOUNTAIN RANGE, THE TERRAIN INTERACTION WILL LEAD TO SLIGHT
WEAKENING, FOLLOWED BY STEADY INTENSIFICATION DRIVEN BY HIGH SEA
SURFACE TEMPERATURES AND OCEAN HEAT CONTENT AFTER IT EXITS INTO THE 
SOUTH CHINA SEA, OFFSET ONLY BY COOLING SEA SURFACE TEMPERATURES. THE 
SYSTEM IS FORECAST TO REACH PEAK INTENSITY OF 60 KTS BY TAU 96, AFTER 
WHICH IT WILL START WEAKENING DUE TO LAND INTERACTION AS IT 
APPROACHES 
HAINAN AND SOUTH CHINA, AS WELL AS A NORTHEASTERLY WIND SURGE 
BRINGING 
COLD AND DRY AIR INTO THE SYSTEM. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGHOUT THE INITIAL 72 HOURS, WITH 70NM CROSS-TRACK SPREAD PRIOR
TO LUZON LANDFALL. THE TRACK GUIDANCE PAST THAT IS SLIGHTLY LESS
CONSISTENT WITH GFS TAKING THE MOST SOUTHERN ROUTE, OFFSET BY
NAVGEM ON THE NORTHERN SIDE, WITH A CROSS-TRACK SPREAD OF OVER 200
NM. JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL
CONSENSUS, SLIGHTLY CLOSER TO THE SOUTHERN TRACKS. INTENSITY
GUIDANCE IS IN FAIR AGREEMENT AND THE JTWC FORECAST IS PLACED ON
THE HIGHER SIDE OF THE MULTI-MODEL CONSENSUS, CLOSER TO THE GFS
GUIDANCE, WITH A PEAK INTENSITY OF 60 KTS BY TAU 96.

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