WDXS31 PGTW 080300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08S (BATSIRAI) 
WARNING NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 26.8S 41.6E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 286 NM SOUTH-SOUTHEAST OF EUROPA ISLAND
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
EXPOSED, BROAD LOW-LEVEL CIRCULATION WITH CONVECTION SHEARED TO THE
SOUTH AND SOUTHEAST. THE INITIAL POSITION IS BASED ON AN EXPOSED
LOW-LEVEL BANDING IN A 072244Z AMSR2 89GHZ IMAGE AND THE INITIAL
INTENSITY IS BASED ON EXTRAPOLATION FROM A 071932Z ASCAT-B IMAGE
SHOWING 45-50 KT WINDS IN THE SOUTHWEST QUADRANT. THE SYSTEM IS
STRUGGLING TO REINTENSIFY DUE TO SIGNIFICANT DRY AIR ENTRAINMENT
FROM THE WEST AND INCREASING VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY SUBTROPICAL RIDGE

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   CIMSS SATCON: 44 KTS AT 072210Z
   CIMSS ADT: 31 KTS AT 072115Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 25-30 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE POLEWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

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: TC 08S IS FORECAST TO ACCELERATE SOUTHWARD
ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE AND BEGIN TO
WEAKEN AS VERTICAL WIND SHEAR INCREASES AND SEA SURFACE
TEMPERATURES COOL TO BELOW 26C OVER THE NEXT 12 HOURS. AS THE
SYSTEM MOVES FURTHER SOUTH AND NEARS THE SUBTROPICAL JET, IT WILL
BEGIN TO TAKE ON MORE SUBTROPICAL CHARATERISTICS AND SHOULD
COMPLETE SUBTROPICAL TRANSITION BY TAU 24 AT THE INTENSITY OF 40
KTS. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH ONLY
A 50NM CROSS-TRACK SPREAD AT TAU 48. INTENSITY GUIDANCE IS ALSO IN
GOOD AGREEMENT, WITH ALL MODELS INDICATING A STEADY WEAKENING TREND
FOR THE REMAINDER OF THE FORECAST.

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