WDPN31 PGTW 232100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (TRAMI) WARNING NR 
014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.4N 122.2E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 182 NM NORTH-NORTHEAST OF MANILA,
PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
CIRCULAR, CENTRAL DENSE OVERCAST COMPRISED OF FRACTURED AND PULSING
CONVECTION DUE TO THE SYSTEM MAKING LANDFALL OVER THE PHILIPPINE
ISLAND OF LUZON. THE WEAK NATURE OF THE SYSTEM IS EVIDENT BY THE
EXTENSIVE FIELDS OF SCATTERED CONVECTIVE ACTIVITY THROUGHOUT THE
REGION, SUGGESTING CURRENTLY POOR ORGANIZATION OF TS 22W. THE
SYSTEM IS ALSO NEIGHBORED BY A LARGE CONVECTIVE PLUME TO ITS
IMMEDIATE SOUTHWEST WHICH IS NOT ASSOCIATED WITH TRAMI ITSELF.
ANIMATED EIR IMAGERY ALSO REVEALS A POSSIBLE LOOPING MOTION TO THE
SOUTH AS THE SYSTEM PRESSES AGAINST THE TERRAIN. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON SURFACE
OBSERVATIONS AND AGENCY FIXES. THE INITIAL INTENSITY OF 45 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON AN EARLIER 231248Z ASCAT-C
UHR IMAGE.

INITIAL WIND RADII BASIS: PERSISTENCE 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   RJTD: T3.0 - 45 KTS
   RCTP: T3.0 - 45 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 10-15 KTS
   SST: OVER LAND
   OUTFLOW: MODERATE WESTWARD
   OTHER FACTORS: LAND INTERACTION

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: AS THE SYSTEM TRACKS WESTWARD ACROSS LUZON, IT
REMAINS TO BE SEEN EXACTLY HOW A LEESIDE JUMP SCENARIO WILL PLAY
OUT, BUT THE GUIDANCE IS SUGGESTING A SOUTHWARD DIP PRIOR TO THE
RELATIVELY STRAIGHT WESTWARD TRACK EXPECTED IN THE LONG TERM. THE
TREK ACROSS THE SOUTH CHINA SEA WILL ALLOW FOR SOME FURTHER
DEVELOPMENT, BUT THE SYSTEM IS EXPECTED TO MAINTAIN A BROAD
HORIZONTAL EXPANSE WHICH WILL INHIBIT ITS ABILITY TO STRENGTHEN
SIGNIFICANTLY. VERTICAL WIND SHEAR IS ALSO EXPECTED TO GRADUALLY
INCREASE IN THE LATER TAUS, AT WHICH POINT THE SYSTEM WILL DEFLECT
SOUTHWARD DUE TO A BLOCKING HIGH SITUATED OVER MYANMAR.

MODEL DISCUSSION: THE TRACK GUIDANCE IS STRUGGLING TO ACCOUNT FOR
THE RANGE OF POSSIBLE SCENARIOS ASSOCIATED WITH THE ANTICIPATED
LEESIDE JUMP ACROSS LUZON AND IS EVIDENCED BY A 70-NM TRACK SPREAD
AT TAU 12. THE CONSENSUS TIGHTENS BY TAU 48 OVER THE SOUTH CHINA
SEA. THE GFS HAS BEEN A LEADER IN DEPICTING A SOUTHWARD TURN AT THE
END OF THE FORECAST PERIOD, WHICH ALIGNS WITH THE SYNOPTIC PATTERN
EXPECTED AT THAT TIME. THE INTENSITY GUIDANCE IS FAILING TO CAPTURE
THE BRIEF PERIOD OF WEAKENING DURING THE STINT OVER LAND, AND
THEREFORE THE JTWC FORECAST IS ON THE LOWER END OF THE GUIDANCE. A
PEAK NEAR TAU 72 IS EXPECTED AND IS ON THE HIGHER END OF THE
INTENSITY CONSENSUS GUIDANCE. THE JTWC TRACK AND INTENSITY
FORECASTS SHARE MEDIUM CONFIDENCE.

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