WDXS31 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING 
NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.9S 117.8E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 349 NM NORTHWEST OF BROOME, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM
HAS BECOME EVEN MORE COMPACT AND DEEP AS FEEDER BANDS TRAILING FROM
THE SOUTH WRAPPED TIGHTER INTO THE CENTRAL DENSE OVERCAST. THE 
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A FORMATIVE 
EYE IN THE EIR LOOP THAT LINED UP VERY WELL WITH A MICROWAVE EYE 
FEATURE IN THE 062243Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY IS 
ALSO ASSESSED WITH HIGH CONFIDENCE BASED ON THE PGTW DVORAK ESTIMATE 
OF 65KTS, CONSISTENT WITH THE FORMATIVE EYE IN THE EIR LOOP. THE 
ENVIRONMENT REMAINS HIGHLY FAVORABLE FOR RAPID INTENSIFICATION (RI) 
WITH WARM SSTS, LOW VWS AND STRONG RADIAL OUTFLOW ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE ADJUSTED FOR INTENSIFICATION.


CURRENT STEERING MECHANISM: NORTHWEST PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE SOUTH.


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   KNES: T3.5 - 55 KTS
   APRF: T3.0 - 45 KTS
   CIMSS ADT: 57 KTS AT 062330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG 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 FREDDY WILL CONTINUE ON ITS CURRENT
SOUTHWESTWARD TRACK OVER THE NEXT 24 HOURS; AFTERWARD, IT WILL
LEVEL OFF ON A MORE WEST-SOUTHWESTWARD DIRECTION AS THE STEERING
STR BUILDS AND EXTENDS WESTWARD. THE HIGHLY FAVORABLE ENVIRONMENT
WILL FUEL RAPID INTENSIFICATION (RI) TO A PEAK OF 105KTS BY TAU 36. 
AFTERWARD, INCREASING VWS AND THE INTRUSION OF MID-LEVEL DRY AIR WILL 
GRADUALLY ERODE THE SYSTEM DOWN TO 80 KTS BY TAU TAU 120.  

MODEL DISCUSSION: NUMERICAL TRACK MODELS ARE IN TIGHT AGREEMENT
WITH A GRADUAL SPREADING TO 160NM BY TAU 120 WITH NAVGEM THE SOLE
LEFT-OF-TRACK OUTLIER. UP TO TAU 72, THERE IS HIGH CONFIDENCE IN
THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF CONSENSUS
TO OFFSET NAVGEM. AFTER TAU 72, THE TRACK CONFIDENCE IS MEDIUM AS
THE SPREAD WIDENS. THE INTENSITY FORECAST IS MEDIUM UP TO TAU 72 THEN 
LOW AFTERWARD DUE TO THE UNCERTAINTY IN THE FORECAST INTENSITY 
DYNAMICS IN THE EXTENDED PERIOD.

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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