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JTWC IS ISSUING 6HOURLY WARNINGS ON TC 18S. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON TC 18S AND INVEST 90W.
SOUTH INDIAN OCEAN/WESTERN AUSTRALIA: TC 18S(ILSA). CURRENT ESTIMATED INTENSITY IS 130 KNOTS CAT 4 US/SUPER TYPHOON AT 13/12UTC.
WARNING 20 ISSUED AT 13/03UTC.
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SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 18S PEAKED IN INTENSITY AROUND 130900Z-131200Z NEAR 130 KNOTS. SURFACE OBSERVATIONS FROM BEDOUT ISLAND INDICATED MAXIMUM SUSTAINED SURFACE WINDS (10-MINUTE AVERAGE) OF 121 KNOTS (129-130 KNOTS CONVERTED TO 1-MINUTE AVERAGE) AT 131320Z WITH MAXIMUM GUSTS OF 156 KNOTS (167 KNOTS CONVERTED TO 1-MINUTE AVERAGE). OVER THE PAST TWO HOURS, ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY INDICATES A SLIGHT WEAKENING TREND WITH THE EYE BECOMING MORE RAGGED AND CLOUD FILLED. A 130909Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS DECAYING SPIRAL BANDING OVER THE SOUTHERN SEMICIRCLE, HOWEVER, ANIMATED RADAR IMAGERY FROM PORT HEDLAND CONTINUES TO SHOW AN INTACT, SYMMETRIC EYEWALL. BASED ON THE LATEST RADAR IMAGERY, THE CENTER WILL MAKE LANDFALL WITHIN THE NEXT TWO HOURS BETWEEN DE GREY AND PARDOO STATION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON RADAR IMAGERY. THE INITIAL INTENSITY OF 130 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE DVORAK INTENSITY ESTIMATES AND THE SURFACE OBSERVATIONS FROM BEDOUT ISLAND.
BOM PORT HEDLAND RADAR
FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: AFTER PASSING JUST EAST OF BEDOUT ISLAND, TC 18S IS EXPECTED TO MAKE LANDFALL NEAR TAU 03 (131500Z). ENVIRONMENTAL CONDITIONS WILL CONTINUE TO DEGRADE AS THE SYSTEM APPROACHES THE COAST AND TRACKS INLAND WITH STEADY WEAKENING EXPECTED. AFTER TAU 06, TC 18S WILL RECURVE SHARPLY SOUTHEASTWARD TO EAST-SOUTHEASTWARD AS IT INTERACTS WITH THE MAJOR SHORTWAVE TROUGH AND EVENTUALLY ACCELERATES WITHIN THE MIDLATITUDE WESTERLIES. RAPID WEAKENING IS EXPECTED WITH DISSIPATION BY TAU 36 OVER CENTRAL AUSTRALIA.
FORECAST LANDFALL AREA
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN VERY TIGHT AGREEMENT THROUGH TAU 24 WITH AN 22NM SPREAD IN SOLUTIONS AT TAU 12 AND A 43NM SPREAD IN SOLUTIONS AT TAU 24. AFTER TAU 24, GUIDANCE DIVERGES GRADUALLY WITH INCREASING UNCERTAINTY ASSOCIATED WITH THE TRACK WITHIN THE MIDLATITUDE WESTERLIES OVER LAND.
RIPA Forecast
HWRF 10m Wind Speed & Sea Level Pressure AT 13/00UTC: 141KNOTS AT +12H.
Multiplatform Satellite Surface Wind Analysis (Experimental)
AMSR-2 AT 13/0527UTC: 116.3 KNOTS( 10 MINUTE AVERAGE)= 132.5 KNOTS(1 MINUTE).
