WDXS31 PGTW 242100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 22S (HORACIO) WARNING 
NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.9S 64.9E
   INITIAL INTENSITY: 95 KTS
   GEOGRAPHIC REFERENCE: 510 NM SOUTHEAST OF PORT LOUIS, MAURITIUS
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHEASTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THAT THE
STRUCTURE OF TROPICAL CYCLONE (TC) 22S (HORACIO) IS COLLAPSING,
WITH DEEP CONVECTION BECOMING INCREASINGLY DISORGANIZED AND CLOUD
TOP TEMPERATURES WARMING OVER THE PAST TWELVE HOURS. ENVIRONMENTAL
CONDITIONS ARE NOW HIGHLY UNFAVORABLE WITH HIGH VERTICAL WIND SHEAR
(30+ KTS), ENTRAINMENT OF SIGNIFICANTLY DRIER MID-LEVEL AIR FROM
THE WEST, AND COOLING ALONG-TRACK SEA SURFACE TEMPERATURES
(CURRENTLY 26-27C). THE INITIAL POSITION IS PLACED WITH MEDIUM
CONFIDENCE BASED ON ANIMATED EIR IMAGERY OF THE HIGHLY OBSCURED
LLCC AND A PARTIAL 241430Z WSF-M PASS. THE INITIAL INTENSITY OF 95
KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON EARLIER 241418Z
SENTINEL-1C SAR DATA DEPICTING A MEAN VALUE OF 100 KTS. A LOWER
INTENSITY IS QUITE POSSIBLE GIVEN THE OBSERVED, RAPID STRUCTURAL
WEAKENING.

INITIAL WIND RADII BASIS: 241418Z SENTINEL-1C SAR DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) CENTERED TO THE
EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   DEMS: T5.5 - 102 KTS
   FMEE: T5.0 - 90 KTS
   FIMP: T4.5 - 77 KTS
   CIMSS ADT: 97 KTS AT 241830Z
   CIMSS AIDT: 100 KTS AT 241830Z
   CIMSS D-PRINT: 82 KTS AT 241830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 30+ KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 22S WILL CONTINUE TRACKING
SOUTH-SOUTHEASTWARD UNDER THE INFLUENCE OF THE SUBTROPICAL RIDGE TO
THE EAST THROUGHOUT THE FORECAST WITH ONLY A BRIEF WESTWARD SHIFT
IN TRACK AFTER TAU 36 AS AN UPPER LEVEL TROUGH TEMPORARILY
INTERFERES WITH THE STEERING MECHANISM. THE INTENSITY OF 22S WILL
WEAKEN AS IT BATTLES WITH ONGOING UNFAVORABLE CONDITIONS (HIGH VWS,
COOLING SST, AND DRY AIR ENTRAINMENT) FOR THE REMAINDER OF THE
FORECAST PERIOD. AROUND TAU 36, THE SYSTEM WILL BEGIN SUBTROPICAL
TRANSITION AS IT ALIGNS WITH AN UPPER-LEVEL LOW APPROACHING FROM
THE WEST. TC 22S IS EXPECTED TO MAINTAIN GALE FORCE WINDS DUE TO
SUPPORTING BAROCLINIC FORCING AS IT TRANSITIONS TO A FULLY
SUBTROPICAL LOW BY TAU 72. THE CIRCULATION WILL LIKELY BE ABSORBED
INTO THE MID-LATITUDE WESTERLY FLOW PATTERN AND UNDERGO
EXTRATROPICAL TRANSITION BEYOND THE CURRENT FORECAST PERIOD.

MODEL DISCUSSION: CROSS TRACK GUIDANCE REMAINS IN GOOD AGREEMENT,
DEPICTING SOUTH SOUTHEASTWARD MOVEMENT WITH A SLIGHT SHIFT TO THE
WEST AFTER TAU 36. THE JTWC FORECASTED TRACK LIES CLOSE TO THE
MULTI MODEL CONSENSUS AND IS LARGELY CONSISTENT WITH THE PREVIOUS
FORECAST, LENDING HIGH CONFIDENCE. INTENSITY GUIDANCE IS SPREAD UP
TO 20 KTS BY TAU 72 WITH GFS RELUCTANT TO BRING INTENSITY DOWN.
HOWEVER, THE REMAINING MEMBERS FOLLOW A STEEPER WEAKENING TREND.
THE JTWC FORECASTED INTENSITY LIES CLOSE TO THE MULTI MODEL
CONSENSUS, IN LINE WITH THE MAJORITY OF THE GUIDANCE, WITH HIGH
CONFIDENCE. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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