WDPN32 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 15W (BOLAVEN) WARNING NR 
019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.9N 142.9E
   INITIAL INTENSITY: 155 KTS
   GEOGRAPHIC REFERENCE: 365 NM SOUTH-SOUTHEAST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 58 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS SUPER
TYPHOON (STY) 15W (BOLAVEN) EXPOSING A 14NM WIDE STADIUM EYE,
SURROUNDED BY A SMOOTH, VERY SYMMETRIC CONVECTIVE CANOPY SPANNING
OUTWARD 80NM FROM THE LOW-LEVEL CIRCULATION CENTER (LLCC). LARGE
SPIRAL BANDS OF DEEP CONVECTION INTERMITTENTLY FLARE WITH
OVERSHOOTING CLOUD TOPS, OBSERVABLE IN ALL BUT THE SOUTHEAST
QUADRANT. EYE TEMPERATURE IS HOVERING AROUND +20C, WHILE CLOUD TOP
TEMPERATURES HAVE BOTTOMED AROUND -81C. CLOUD TO GROUND LIGHTNING
DATA REVEALS LIGHTNING HAS PERSISTED CONTINUOUSLY IN AND AROUND THE
SYSTEMS EYE SINCE THE PREVIOUS WARNING (018). ALL SAID, THIS
COMPACT AND VERY WELL-ORGANIZED SUPER TYPHOON HAS MANAGED TO
CONSOLIDATE AND INTENSIFY EVEN FURTHER OVER THE PAST SIX HOURS. THE
INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED A 111200Z
HIMAWARI-9 EIR IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE BASED ON SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES
LISTED BELOW AND EXTRAPOLATION OF A 110840Z RCM-1 SAR IMAGE SHOWING A 
MAXIMUM WIND VELOCITY OF 147KTS. WIND RADII WERE ADJUSTED TO PARALLEL 
THE AFOREMENTIONED SAR DATA.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T7.5 - 155 KTS
   RJTD: T7.5 - 155 KTS
   KNES: T7.5 - 155 KTS
   CIMSS ADT: 155 KTS AT 111300Z
   CIMSS AIDT: 148 KTS AT 111150Z
   CIMSS DPRINT: 149 KTS AT 111200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: STY 15W IS FORECAST TO MAINTAIN CURRENT
INTENSITY THROUGH TAU 12 ON A NORTHWARD TRAJECTORY. BETWEEN TAU 12
AND TAU 24, INTENSITY IS EXPECTED TO GRADUALLY BEGIN TO FALL AS STY
15W TURNS TO A NORTHEASTWARD TRACK. AFTER TAU 24, THE ENVIRONMENT
STARTS TO BECOME LESS FAVORABLE. VERTICAL WIND SHEAR IS ANTICIPATED TO 
SLOWLY ONSET AND BECOME SIGNIFICANT (+30KTS) BY TAU 48. ADDITIONALLY, 
DRY AIR (LESS THAN 30 PERCENT RELATIVE HUMIDITY)
ALONG THE WESTERN PERIPHERY WILL BEGIN WRAPPING AROUND AND INTO THE
VORTEX NEAR TAU 39. BOTH FACTORS WILL INHIBIT INTENSIFICATION AND
SLOWLY DECAY STORM STRUCTURE THROUGH TAU 96. THE SYSTEM WILL PASS
THE 26C ISOTHERM AS IT CROSSES 35N AND BEGIN EXTRATROPICAL
TRANSITION (ETT) AROUND TAU 72. RAPID TRANSITION 
TO TYPHOON STRENGTH, WARM SECLUSION TYPE EXTRATROPICAL LOW IS
EXPECTED BY TAU 96 TO THE SOUTH-SOUTHWEST OF KISKA ISLAND.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT THROUGH TAU 72, AND FAIR AGREEMENT BY TAU 120.  AT TAU
72, THE FURTHEST TRACK SEPARATION OF JTWC CONSENSUS MEMBER IS
BETWEEN THE JGSM AND GFS SOLUTIONS, WITH A CROSS-TRACK SPREAD OF
181NM. ALONG-TRACK SPREAD OF 398NM IS GREATEST BETWEEN GFS AND
ECMWF SOLUTIONS.  BY TAU 120, BOTH SPREADS AMONG JTWC CONSENSUS
MEMBERS INCREASE; NAVGEM AND GFS SOLUTIONS EXHIBIT A CROSS
TRACK-SPREAD OF 422NM, WHILE GFS AND UKMET SHARE AN ALONG-TRACK SPREAD 
OF 425NM. INTENSITY GUIDANCE UNIFORMLY SUGGESTS THE SYSTEM
INTENSITY HAS LIKELY PEAKED AND WILL GRADUALLY TREND DOWNWARD AFTER
A BRIEF SUSTAINMENT PERIOD THROUGH TAU 12.

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