WDXS32 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 15S (ANIKA) WARNING 
NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.8S 121.1E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 83 NM SOUTHWEST OF BROOME, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS THAT THE LOW
LEVEL CIRCULATION CENTER (LLCC) HAS MOVED UNDER THE CENTRAL
CONVECTION WITH BANDING FEATURES IN THE SOUTHERN SEMICIRCLE
WRAPPING INTO THE LLCC. A 012203Z SSMIS MICROWAVE IMAGE DEPICTS
THAT A SINGLE DEEP CONVECTIVE BAND COMPOSES THE PRIMARY STRUCTURE
OF TC 15S. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON MSI AND MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 35 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A HEDGE BETWEEN AGENCY
DVORAK CURRENT INTENSITY AND ADT CURRENT INTENSITY.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   APRF: T2.0 - 30 KTS
   CIMSS SATCON: 49 KTS AT 012204Z
   CIMSS ADT: 41 KTS AT 012350Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 31-32 CELSIUS
   OUTFLOW: WEAK POLEWARD AND EQUATORWARD
   OTHER FACTORS: INTERACTION WITH AUSTRAILAN COASTLINE

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 15S IS EXPECTED TO CONTINUE TO TRACK
SOUTHWESTWARD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE
TO THE SOUTHEAST. TC 15S IS FORECAST TO REACH A PEAK INTENSITY OF
40 KNOTS NEAR TAU 12 AS IT CONTINUES IN A FAVORABLE ENVIRONMENT
CHARACTERIZED BY WARM SEA SURFACE TEMPERATURES (SST), LOW VERTICAL
WIND SHEAR (VWS) AND INCREASING DIVERGENCE ALOFT. THE SYSTEM IS
FORECAST TO MAKE LANDFALL NEAR TAU 12 AND PROCEED INLAND OVER
NORTHWESTERN AUSTRALIA AND THROUGH TAU 24 CONTINUE TO TURN
SOUTH-SOUTHEASTWARD AS A MID-LATITUDE TROUGH WEAKENS THE
SUBTROPICAL RIDGE. TC 15S IS FORECAST TO STEADILY WEAKEN AS IT
TRACKS OVER THE NORTHWESTERN PLAINS OF AUSTRALIA, EVENTUALLY
DISSIPATING NEAR TAU 36.

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, NUMERICAL MODEL
GUIDANCE IS IN UNANIMOUS AGREEMENT WITH THE JTWC FORECAST TRACK
WITH AN 18NM SPREAD AT TAU 36. RELIABLE INTENSITY GUIDANCE IS IN
GOOD AGREEMENT THROUGH THE FORECAST PERIOD WITH ALL MEMBERS SHOWING
A PEAK IN INTENSITY AT TAU 12 FOLLOWED BY A STEADY WEAKENING TREND
AS THE SYSTEM MAKES LANDFALL. 


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