WDPN32 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN) WARNING NR 
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.6N 152.5E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 510 NM EAST-SOUTHEAST OF ANDERSEN AFB,
GUAM
   MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A
CONSOLIDATING SYSTEM WITH DEEP OVERSHOOTING CONVECTION IN THE
CENTRAL DENSE OVERCAST THAT IS OBSCURING THE LOW LEVEL CIRCULATION.
THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON LOW
LEVEL NOTCH FEATURES IN THE 080341Z AMSR2 AND 080518Z SSMIS
MICROWAVE IMAGES. THE INITIAL INTENSITY OF 40KTS IS BASED ON OVERALL 
ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE 
GRADUAL CONSOLIDATION. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT 
WITH MODERATE POLEWARD OUTFLOW AND VERY WARM ALONG-TRACK SST OFFSET 
BY MODERATE VWS.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTH-NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.5 - 35 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 54 KTS AT 080329Z
   CIMSS ADT: 57 KTS AT 080530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD
   OTHER FACTORS: ENVIRONMENT BECOMES HIGHLY FAVORABLE AFTER TAU 72
WITH INCREASED POLEWARD OUTFLOW 

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 15W WILL TRACK WEST-NORTHWESTWARD THEN
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE
NORTH-NORTHEAST AND WILL COME TO WITHIN 57NM OF ANDERSEN AFB AS IT
TRACKS NORTHEAST OF GUAM JUST AFTER TAU 48. AFTERWARD, A
MID-LATITUDE TROUGH EXITING JAPAN TO THE NORTHWEST WILL WEAKEN THE
STR AND ALLOW THE SYSTEM TO TRACK MORE NORTHWARD TOWARD IWO TO. THE
FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO 80KTS
AT TAU 48. AFTERWARD, LOW VWS AS THE CYCLONE ROUNDS THE STR AXIS
AND INCREASING POLEWARD OUTFLOW AHEAD OF THE MID-LATITUDE TROUGH
WILL PROMOTE A RAPID INTENSIFICATION TO A PEAK OF 125KTS BY TAU 96.
AFTERWARD, INCREASING VWS WILL BEGIN TO ERODE THE SYSTEM DOWN TO
120KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS HAVE COME INTO TIGHTER AGREEMENT
WITH A GRADUAL AND EVEN SPREAD TO 124NM BY TAU 72 THEN TO 269NM BY
TAU 120 WITH NAVGEM THE SOLE LEFT OF TRACK OUTLIER IN THE EXTENDED
TAUS. GIVEN THE FORMATIVE NATURE OF THE SYSTEM, THERE IS ONLY MEDIUM 
CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT 
OF CONSENSUS AFTER TAU 72 TO OFFSET NAVGEM. 

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