WDPN32 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.8N 153.2E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 541 NM EAST-SOUTHEAST OF ANDERSEN AFB,
GUAM
   MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 13 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A
DISORGANIZED, ALBEIT CONSOLIDATING SYSTEM WITH DEEP FLARING
CONVECTION OBSCURING THE LOW LEVEL CIRCULATION. THE INITIAL
POSITION IS PLACED WITH LOW CONFIDENCE BASED ON CURRENT STORM 
MOTION AND LOW CLOUD TRACING IN THE EIR LOOP. THE INITIAL INTENSITY 
OF 35KTS IS BASED ON THE HIGH END OF AGENCY DVORAK AND AUTOMATED 
DVORAK ESTIMATES AND REFLECTS THE GRADUAL CONSOLIDATION. ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VWS, 
MODERATE POLEWARD OUTFLOW, AND VERY WARM ALONG-TRACK SST.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T2.0 - 30 KTS
   KNES: T2.5 - 35 KTS
   CIMSS ADT: 35 KTS AT 071140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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
NORTHEAST AND WILL COME TO WITHIN 32NM OF ANDERSEN AFB AS IT TRACKS
NORTHEAST OF GUAM AND ROTA JUST BEFORE TAU 72. 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 72. AFTERWARD, INCREASE POLEWARD OUTFLOW AHEAD OF THE
MID-LATITUDE TROUGH WILL PROMOTE A RAPID INTENSIFICATION, AND BY
TAU 120, REACHING 120 KTS. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 265NM BY TAU 72 THEN TO 370NM BY TAU 120
WITH NAVGEM THE SOLE LEFT OF TRACK OUTLIER. 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 TO
OFFSET NAVGEM. 

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