WDXS32 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 15S (ANIKA) WARNING 
NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.0S 127.6E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 195 NM WEST OF DARWIN, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
CONSOLIDATING SYSTEM WITH A REGION OF DEEP, COLD CONVECTION WITH
SOME CONVECTION BEING SHEARED OFF TO THE NORTHWEST. THE INITIAL
POSITION IS BASED ON THE CENTER OF THE BROAD AREA OF CONVECTION IN
EIR. THE INITIAL INTENSITY OF 45 KTS IS BASED ON THE PGTW DVORAK
CURRENT INTENSITY ESTIMATE, WHICH IS IN AGREEMENT WITH KNES, ADRM,
AND ADT FIXES. TC 15S IS CURRENTLY IN A MARGINALLY FAVORABLE
ENVIRONMENT WITH LOW VERTICAL WIND SHEAR, WARM SEA SURFACE
TEMPERATURES, AND MODERATE POLEWARD OUTFLOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WEAK STEERING PATTERN

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   ADRM: T3.0 - 45 KTS
   CIMSS ADT: 45 KTS AT 251740Z

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

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: AFTER REMAINING QUASI-STATIONARY IN THE JOSEPH
BONAPARTE GULF WITHIN A WEAK STEERING PATTERN, TC 13S SEEMS TO 
HAVE BEGUN TO DRIFT GENERALLY SOUTHWESTWARD. THE SYSTEM IS EXPECTED
TO TRACK GENERALLY SOUTHWARD OVER THE NEXT 24 HOURS IN THE WEAK
STEERING ENVIRONMENT. AROUND TAU 36, THE SUBTROPICAL RIDGE (STR) TO
THE SOUTH WILL BUILD, STEERING TC 15S TO THE WEST OVER CAPE TALBOT.
BY TAU 72, THE RIDGE WILL REORIENT AND PUSH THE SYSTEM SOUTHWEST
DOWN THE KIMBERLY COAST THROUGH THE REMAINDER OF THE FORECAST
PERIOD. TC 13S WILL REACH 50 KTS AROUND TAU 12 AND MAY DECREASE TO
45 KNOTS AFTERWARDS AS LAND INTERACTION SLIGHTLY HINDERS THE SYSTEM.
THE SYSTEM IS EXPECTED TO REMAIN AROUND 45-50KTS FOR THE REMAINDER
OF THE FORECAST.

MODEL DISCUSSION: THERE IS CURRENTLY HIGH UNCERTAINTY IN THE TRACK
AND INTENSITY FORECAST DUE TO DISAGREEMENT IN THE MODELS. GFS
CURRENTLY SHOWS THE SYSTEM DOING A LOOP IN THE JOSEPH BONAPARTE
GULF BEFORE HEADING WEST AND DECREASING IN INTENSITY. ECMWF
CURRENTLY SHOWS THE SYSTEM TRACKING SOUTHWESTWARD ALONG THE
KIMBERLY COAST WITH STEADY INTENSIFICATION, HOWEVER, THIS IS
DRASTICALLY DIFFERENT FROM ECMWF MODELS RUNS 24 HOURS AGO WHICH
KEPT THE SYSTEM QUASI-STATIONARY IN THE JOSEPH BONAPARTE GULF. 

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