WDXS31 PGTW 291500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08S (BATSIRAI) 
WARNING NR 006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.0S 69.9E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 378 NM EAST-NORTHEAST OF PORT MATHURIN,
MAURITIUS
   MOVEMENT PAST 6 HOURS: WESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS
MAINTAINED A COMPACT AND FAIRLY SYMMETRICAL STRUCTURE WITH SLIGHT
IMPROVEMENT IN THE FEEDER BAND WRAP AND THE APPEARANCE OF A
FORMATIVE EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON A MICROWAVE EYE FEATURE IN THE AMSR2 PASS AT 290838Z, THE
HALFWAY POINT FROM THE LAST BEST TRACK POSITION. THE INITIAL
INTENSITY OF 70KTS IS BASED ON AN OVERALL ASSESSMENT OF AGENCY AND
AUTOMATED DVORAK ESTIMATES AND REFLECTS THE SLIGHT 6-HR IMPROVEMENT.
ANALYSIS INDICATES A HIGHLY FAVORABLE ENVIRONMENT WITH LOW VWS,
STRONG WESTWARD OUTFLOW, AND WARM (29-30C) ALONG-TRACK SST IN THE
SOUTH INDIAN OCEAN.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: NORTHERN PERIPHERY OF THE SUBTROPICAL
RIDGE (STR) TO THE SOUTH.


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   FMEE: T4.0 - 65 KTS
   CIMSS SATCON: 61 KTS AT 290844Z
   CIMSS ADT: 74 KTS AT 291215Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG WESTWARD

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: TC BATSIRAI WILL CONTINUE GENERALLY WESTWARD
ON ITS CURRENT TRACK UNDER THE STR INFLUENCE. AFTER TAU 24, A
SECONDARY STR WILL BUILD FROM THE SOUTHWEST, ASSUME STEERING, AND
DRIVE THE CYCLONE WEST-NORTHWESTWARD UP TO TAU 48; AFTERWARD, THE 
TRACK WILL RETURN TO A WESTWARD TRAJECTORY AS THE STR RECEDES 
EASTWARD. THE FAVORABLE ENVIRONMENT WILL FUEL A STEADY 
INTENSIFICATION, REACHING 105KTS BY TAU 120, AS IT PASSES NORTH OF 
LA REUNION.  

MODEL DISCUSSION: NUMERICAL MODELS HAVE COME TO A BETTER AGREEMENT
WITH NAVGEM THE NOTABLE OUTLIER ON THE LEFT MARGIN OF THE MODEL
ENVELOPE, LENDING MEDIUM CONFIDENCE TO THIS PORTION OF THE JTWC
TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF THE MODEL
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// 
NNNN