WDPS31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 18P (ALFRED) WARNING NR 
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.4S 154.5E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 281 NM EAST-NORTHEAST OF WILLIS ISLAND,
AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS
BEGUN TO TRACK POLEWARD AS IT FURTHER CONSOLIDATED AND DEEPENED.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A
BULLSEYE FEATURE IN THE 242238Z ASCAT PASS. THE INITIAL INTENSITY
IS BASED ON OVERALL ASSESSMENT OF AGENCY AND AUTOMATED ESTIMATES
AND REFLECTS THE 12-HR IMPROVEMENT. ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT WITH LOW VWS, WARM SST, AND MODERATE DUAL OUTFLOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE
NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   ABRF: T3.5 - 55 KTS
   CIMSS SATCON: 72 KTS AT 242238Z
   CIMSS ADT: 79 KTS AT 242330Z
   CIMSS DPNT: 51 KTS AT 242330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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 ALFRED WILL CONTINUE TO TRACK SOUTHWARD
UNDER THE STEERING INFLUENCE OF THE BUILDING NER. THE FAVORABLE
ENVIRONMENT WILL FUEL STEADY INTENSIFICATION TO A PEAK OF 85KTS BY
TAU 24. AFTERWARD, INCREASING VWS WILL MAINLY BE RESPONSIBLE FOR
ITS GRADUAL WEAKENING DOWN TO 50KTS BY TAU 120 AS IT APPROACHES THE
CENTRAL EAST COAST OF AUSTRALIA. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 169NM BY TAU 72, LENDING MEDIUM CONFIDENCE
TO THIS PORTION OF THE JTWC TRACK FORECAST; THEN TO A MUCH WIDER
SPREAD OF 418NM BY TAU 120, LENDING LOW CONFIDENCE TO THE EXTENDED
PORTION OF THE TRACK FORECAST.   

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