WTXS31 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 20S (MITCHELL) WARNING NR 015//
RMKS/
1. TROPICAL CYCLONE 20S (MITCHELL) WARNING NR 015    
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   091200Z --- NEAR 25.3S 113.8E
     MOVEMENT PAST SIX HOURS - 155 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF 
     SATELLITE, RADAR AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 25.3S 113.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   100000Z --- 27.2S 115.4E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
091500Z POSITION NEAR 25.8S 114.2E.
09FEB26. TROPICAL CYCLONE 20S (MITCHELL), LOCATED APPROXIMATELY
181 NM SOUTH OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTH-
SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED 
INFRARED SATELLITE IMAGERY (EIR) DEPICTS A DECOUPLING VORTEX, WITH THE 
UPPER-LEVEL ROTATION ALREADY LOCATED OVER THE SOUTHERN PORTION OF 
SHARK BAY, WHILE THE LOW-LEVEL CIRCULATION CENTER (LLCC) IS LOCATED 
JUST SOUTH OF CARNARVON, AUSTRALIA BASED ON RADAR ANALYSIS. SURFACE 
WINDS AT CARNARVON SHIFTED FROM NORTHERLY TO WESTERLY BETWEEN 1100Z-
1200Z, ACCOMPANIED BY A MINIMUM IN SEA LEVEL PRESSURE OF 988.4MB AT 
THE SAME TIME, SUPPORTING THE PASSAGE OF THE LLCC OVER THE STATION IN 
THAT WINDOW OF TIME. ANIMATED RADAR DATA SUGGESTS A SMALL LLCC 
STRADDLING THE COASTLINE SOUTHWEST OF CALLAGIDDY AT 1200Z, MOVING 
SOUTHEASTWARD ALONG THE EASTERN COAST OF SHARK BAY. A 091106Z WSF-M 
37GHZ MICROWAVE IMAGE DEPICTED AN ELONGATED LLCC JUST WEST OF 
CARNARVON. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED 
ON THE RADAR ANALYSIS AND EXTRAPOLATION OF THE LLCC IN THE WSF-M 
IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE, BASED 
ONA PGTW DVORAK ESTIMATE OF T3.0-T3.5, A RAW ADT OF T3.0, AIDT OF 
46KTS, CIMSS DPRINT ESTIMATE OF 41KTS AND A DMINT ESTIMATE OF 42KTS. 
TC 20S WILL CONTINUE TO TRACK SOUTHEASTWARD, STRADDLING THE COASTLINE 
FOR THE NEXT COUPLE OF HOURS BEFORE MOVING FURTHER INLAND TO A 
POSITION NORTHEAST OF GERALDTON BY TAU 12. ENVIRONMENTAL CONDITIONS 
ARE ALREADY UNFAVORABLE, AND THE SYSTEM WILL RAPIDLY WEAKEN OVER THE 
NEXT 12 HOURS AS INCREASING SHEAR LEADS TO RAPID VORTEX DECOUPLING AND 
FRICTIONAL EFFECTS REDUCE THE WIND SPEEDS SURROUNDING THE LOWER-LEVEL 
VORTEX. THE SYSTEM IS FORECAST TO DISSIPATE AS A TROPICAL CYCLONE WITH 
THE NEXT 12 HOURS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE 
JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY 
MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE AT 
091200Z IS 991 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 091200Z IS 18 
FEET. REFER TO TROPICAL CYCLONE 21S (GEZANI) WARNINGS (WTXS32 PGTW)
FOR TWELVE-HOURLY UPDATES.//
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