WDXS32 PGTW 180900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 10S (TEN) WARNING NR 
002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.3S 118.1E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 66 NM NORTH-NORTHWEST OF PORT HEDLAND,
AUSTRALIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A MEDIUM-SIZED
SYSTEM JUST OFF THE COAST OF AUSTRALIA THAT HAS MOSTLY MAINTAINED
ITS CONVECTIVE SIGNATURE OVER THE LAST SIX HOURS. HOWEVER, THE LOW
LEVEL CIRCULATION CENTER (LLCC) HAS BECOME PARTIALLY EXPOSED AND
FORMATIVE BANDS HAVE BECOME MORE DEFINED. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE PARTLY EXPOSED LLCC IN MSI
LOOP THAT WAS CONCENTRIC WITH A DEFINED LLCC IN A COMPOSITE RADAR
LOOP FROM ABOM HEDLAND RADAR SITE. THE INITIAL INTENSITY IS ASSIGNED 
ALSO WITH HIGH CONFIDENCE BASED ON THE PGTW DVORAK INTENSITY OF T2.5 
AND THE AVERAGE OF AUTOMATED INTENSITY ESTIMATES AND REFLECTS THE 
SUSTAINED CONVECTIVE SIGNATURE. ANALYSIS INDICATES A HIGHLY FAVORABLE
ENVIRONMENT WITH WARM SST, MODERATE RADIAL OUTFLOW AND LOW VWS.

INITIAL WIND RADII BASIS: PERSISTENCE. 

CURRENT STEERING MECHANISM: BUILDING SUBTROPICAL RIDGE (STR) TO THE
SOUTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.0 - 30 KTS
   CIMSS ADT: 39 KTS AT 180530Z
   CIMSS AIDT: 36 KTS AT 180530Z
   CIMSS DPNT: 33 KTS AT 180530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 10S WILL TRACK MORE WEST-SOUTHWESTWARD THEN
SOUTHWESTWARD AROUND THE NORTHWESTERN PERIPHERY OF THE STEERING
STR. THE HIGHLY FAVORABLE ENVIRONMENT WILL FUEL RAPID INTENSIFICATION 
TO 65KTS BY TAU 24 THEN TO A PEAK OF 85KTS BY TAU 48. AFTERWARD, 
COOLING SST, INCREASING VWS AND DRY AIR INTRUSION WILL GRADUALLY ERODE 
THE SYSTEM DOWN TO 40KTS BY TAU 120. 

MODEL DISCUSSION: AVAILABLE NUMERICAL MODELS ARE IN TIGHT AGREEMENT
WITH AN EVEN AND GRADUAL SPREAD TO 120NM BY TAU 72, LENDING HIGH
CONFIDENCE TO THIS PORTION OF THE JTWC TRACK FORECAST; AFTERWARD,
THE MODELS SPREAD MORE UNEVENLY TO 417NM, LENDING ONLY MEDIUM 
CONFIDENCE TO THE EXTENDED PORTION OF THE TRACK FORECAST. AFUM IS THE 
NOTABLE OUTLIER ON THE LEFT MARGIN OF THE ENVELOPE, WHICH IS NOT IN 
LINE WITH THE STEERING STR FORECAST TO BUILD. THE JTWC TRACK FORECAST 
IS ADJUSTED TO OFFSET AFUM.

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