WDXS31 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING 
NR 038//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.7S 49.6E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 160 NM SOUTHEAST OF ANTANANARIVO,
MADAGASCAR
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 45 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THE SYSTEM
REMAINS COMPACT AND SYMMETRICAL WITH A DEFINED 6-NM PINHOLE EYE AS
IT IS ABOUT TO MAKE LANDFALL INTO CENTRAL MADAGASCAR. THE EYE HAS
SINCE BECOME CLOUD-COVERED AND THE WESTERN HALF OF THE SYSTEM HAS
INTRUDED INTO MADAGASCAR WITH EARLY INDICATIONS OF UNRAVELING. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE
FEATURE IN THE EIR LOOP. THE INITIAL INTENSITY IS ALSO ASSESSED WITH
HIGH CONFIDENCE BASED ON CLOSELY-CLUSTERED AGENCY AND AUTOMATED
DVORAK ESTIMATES AND REFLECTS THE SLIGHT 12-HOUR WEAKENING. THE
ENVIRONMENT, FOR NOW, REMAINS FAVORABLE WITH LIGHT VWS, STRONG
RADIAL OUTFLOW AND WARM SSTS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   DEMS: T5.5 - 102 KTS
   FMEE: T5.5 - 102 KTS
   CIMSS SATCON: 117 KTS AT 211002Z
   CIMSS ADT: 102 KTS AT 210900Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 FREDDY WILL CONTINUE ON A WEST-SOUTHWESTWARD 
TRACK, MAKE LANDFALL OVER THE NEXT FEW HOURS AND CROSS MADAGASCAR, 
EXIT INTO THE MOZAMBIQUE CHANNEL SHORTLY AFTER TAU 24, THEN MAKE A 
FINAL LANDFALL OVER SOUTHERN MOZAMBIQUE AROUND TAU 66. THE RUGGED 
TERRAIN OF MADAGASCAR WILL SIGNIFICANTLY ERODE THE CYCLONE DOWN TO 
40KTS BY TAU 24. AFTERWARD, THE WARM WATERS OF THE MOZAMBIQUE CHANNEL 
WILL FUEL A MODEST INTENSIFICATION TO 60KTS BY TAU 48. AFTER ITS 
FINAL LANDFALL, THE RUGGED TERRAIN OF MOZAMBIQUE WILL RAPIDLY ERODE 
THE SYSTEM DO DISSIPATION BY TAU 96.

MODEL DISCUSSION: NUMERICAL TRACK MODELS ARE IN VERY TIGHT AGREEMENT 
WITH A GRADUAL AND EVEN SPREAD TO 108NM AT TAU 72; AFTERWARD, THE 
MODELS ERRATICALLY SPREAD OUT, AN INDICATION OF A WEAK VORTEX. IN 
VIEW OF THIS, THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST UP 
TO TAU 72 THEN LOW CONFIDENCE AFTERWARD. GIVEN THE UNCERTAINTIES 
ASSOCIATED WITH LAND CROSSINGS, THERE IS LOW CONFIDENCE IN THE JTWC 
INTENSITY FORECAST UP TO TAU 96

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