WDXS31 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (ELEVEN) WARNING NR 
010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 18.5S 58.8E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 128 NM NORTHEAST OF PORT LOUIS, MAURITIUS
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM
CONTINUES TO STRUGGLE AS IT TRACKS ALONG THE NORTHERN PERIPHERY OF
THE SUBTROPICAL RIDGE (STR) TO THE SOUTH-SOUTHEAST AND STRADDLING A
ZONE OF MODERATE VERTICAL WIND SHEAR. THE CENTRAL DENSE OVERCAST
IS SHEARED NORTHWESTWARD, EXPOSING THE LOW LEVEL CIRCULATION CENTER
(LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON THE EXPOSED LLCC. THE INITIAL INTENSITY IS PLACED WITH MEDIUM
CONFIDENCE BASED ON THE AUTOMATED CIMSS ESTIMATES AND REFLECTS THE
SUSTAINED CONVECTIVE SIGNATURE. ANALYSIS INDICATES A MARGINAL
ENVIRONMENT WITH WARM SST AND MODERATE WESTWARD OUTFLOW OFFSET BY
MODERATE VWS AND DRY AIR IN THE MID-LEVELS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

CURRENT STEERING MECHANISM: STR TO THE SOUTH-SOUTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   DEMS: T2.0 - 30 KTS
   CIMSS ADT: 33 KTS AT 012330Z
   CIMSS SATCON: 37 KTS AT 012100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE WESTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   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 11S WILL CONTINUE TO TRACK GENERALLY
WEST-SOUTHWESTWARD UNDER THE STEERING STR. AFTER TAU 24, A SECONDARY 
STR BUILDING FROM THE SOUTHWEST WILL ASSUME STEERING AND DRIVE THE 
CYCLONE ON A MORE WEST-NORTHWESTWARD TRACK, MAKING LANDFALL OVER 
NORTHEASTERN MADAGASCAR JUST AROUND TAU 60. THE ENVIRONMENT WILL BECOME 
MORE FAVORABLE WITH DECREASING MID-LEVEL DRY AIR INTRUSION AND VWS AND 
PROMOTE INTENSIFICATION TO 50KTS AT TAUS 36-48. AFTER LANDFALL, THE 
RUGGED TERRAIN WILL RAPIDLY ERODE THE SYSTEM TO 30KTS BY TAU 96. 
AFTERWARD, THE SYSTEM WILL EXIT INTO THE WARM MOZAMBIQUE CHANNEL, 
RAPIDLY REGAINING INTENSITY TO 50KTS BY TAU 120.  

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
WITH A GRADUAL AND EVEN SPREAD TO 155NM AT TAU 72 AND 188NM AT TAU
120. HOWEVER, GIVEN THE UNCERTAINTY IN THE FORECAST INTENSITIES DUE
TO LAND INTERACTION THAT CAN ALSO IMPACT THE TRACK, THERE IS ONLY
MEDIUM CONFIDENCE TO THE JTWC TRACK AND INTENSITY FORECASTS. 

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