WDPS31 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07P (KIRRILY)    
WARNING NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.3S 139.1E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 39 NM SOUTH OF MORNINGTON ISLAND,
                         AUSTRALIA
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 07P HAS CONTINUED TO CONSOLIDATE OVER THE PAST 
SIX HOURS, WITH THE UPPER-LEVEL CIRCULATION CENTER NOW VERTICALLY 
ALIGNED WITH THE LOW-LEVEL CIRCULATION CENTER (LLCC). ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A WELL-ORGANIZED 
TROPICAL CYCLONE WITH A CENTRAL DENSE OVERCAST FEATURE OBSCURING THE 
LLCC WITH CONVECTIVE BANDING WRAPPING INTO THE CENTER. ANIMATED RADAR 
IMAGERY REVEALS TIGHTLY-CURVED BANDING WRAPPING INTO A WELL-DEFINED 
LLCC, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. 
SURFACE OBSERVATIONS FROM MORNINGTON ISLAND RANGE FROM 31-35 KNOTS 
SUSTAINED (10-MINUTE AVERAGE) WITH GUSTS 43-46 KNOTS. WHEN ADJUSTED TO 
A 1-MINUTE AVERAGE, THESE SUSTAINED WINDS RANGE FROM ABOUT 33-37 
KNOTS. BASED ON THE SURFACE OBSERVATIONS, SLP VALUES AND THE OVERALL 
CONVECTIVE STRUCTURE, THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS 
WITH MEDIUM CONFIDENCE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WEAK STEERING ENVIRONMENT HAS RESULTED
IN A QUASI-STATIONARY TRACK MOTION OVER THE PAST 18 HOURS.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: TROPICAL CYCLONE (TC) 07P IS EXPECTED TO TRACK
SLOWLY SOUTHWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING
INFLUENCE OF A WEAK STEERING RIDGE TO THE EAST AND SOUTHEAST. THE
SYSTEM IS EXPECTED TO WEAKEN SLOWLY AS IT APPROACHES THE COAST AND
SHOULD TRACK INLAND AND DISSIPATE BY TAU 36. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
LENDING MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST. RELIABLE
INTENSITY GUIDANCE SUPPORTS THE GRADUAL WEAKENING TREND.

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