WDXS31 PGTW 120300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING 
NR 019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.0S 101.2E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 300 NM SOUTHEAST OF COCOS ISLAND,
AUSTRALIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A COMPACT
SYSTEM WITH A SYMMETRICAL CENTRAL DENSE OVERCAST THAT HAS DEEPENED
OVER THE LAST 12 HOURS AND MAINTAINED A SINCE-FILLED PINHOLE EYE.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE
DIMPLED EYE FEATURE IN THE MSI LOOP. THE INITIAL INTENSITY IS ALSO
PLACED WITH HIGH CONFIDENCE BASED ON CLOSELY CLUSTERED AND EQUALLY
ESTIMATED AGENCY DVORAK ESTIMATES AND REFLECTS THE 12-HR
INTENSIFICATION. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH
MODERATE TO STRONG VWS OFFSET BY WARM SST AND STRONG RADIAL
OUTFLOW.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO
THE SOUTH.


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   KNES: T6.0 - 115 KTS
   DEMS: T6.0 - 115 KTS
   APRF: T6.0 - 115 KTS
   CIMSS ADT: 87 KTS AT 112330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 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 A GENERALLY WESTWARD 
TO WEST-SOUTHWESTWARD TRACK UNDER THE STEERING STR. THE ENVIRONMENT 
WILL BECOME LESS FAVORABLE WITH THE INCURSION OF DRY AIR IN THE MID-
LEVELS CAUSING A GRADUAL WEAKENING TO 75KTS BY TAU 48. AFTERWARD, THE 
DIMINISHING DRY AIR AND INCREASING POLEWARD OUTFLOW WILL FUEL ANOTHER 
RE-INTENSIFICATION PHASE, ALBEIT MORE GRADUAL, TO 90KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
AN EVEN AND GRADUAL SPREAD TO 222NM BY TAU 120, LENDING HIGH
CONFIDENCE TO THE JTWC TRACK FORECAST. THE INTENSITY FORECAST IS AT
MEDIUM CONFIDENCE FOR THE DURATION OF THE FORECAST DUE TO THE
UP-AND-DOWN INTENSITY CHANGES. 


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