Invest 91B & Invest 93S: Tropical Cyclone Formation Alert// Invest 94S: still Low at the moment,20/06utc

JTWC IS ISSUING 3HOURLY SATELLITE BULLETINS ON INVEST 93S, INVEST 91B AND INVEST 94S.

FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 130 NM EITHER SIDE OF A LINE FROM 10.2N 93.8E TO 16.1N 94.2E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 23 TO 28 KNOTS. METSAT IMAGERY AT 200000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.5N 93.8E. THE SYSTEM IS MOVING NORTHWARD AT 11 KM/H. 2. REMARKS: THE AREA OF CONVECTION (INVEST 91B) PREVIOUSLY LOCATED NEAR 09.9S 93.7E IS NOW LOCATED NEAR 10.5S 93.8E, APPROXIMATELY 740KM SOUTH-SOUTH WEST OF YANGON, MYANMAR. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION WITH IMPROVING CONVECTIVE BANDING. A 192234Z SSMIS 91GHZ MICROWAVE IMAGE DEPICTS IMPROVED LOW LEVEL BANDING FEATURES AND FRAGMENTED CONVECTIVE BANDS ON THE NORTHEAST SIDE EXTENDING TO THE SOUTH IN VICINITY OF THE NICOBAR ISLANDS. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH INCREASING POLEWARD OUTFLOW, AND LOW (05-10 KNOTS) VERTICAL WIND SHEAR (VWS). SEA SURFACE TEMPERATURE VALUES (29-30C) ARE CONDUCIVE FOR FURTHER DEVELOPMENT. TRACK GUIDANCE INDICATES A NORTHERLY TRACK OVER THE NEXT 48 HOURS, WITH A POSSIBLE LANDFALL ALONG THE WESTERN PORTION OF THE MYANMAR COAST. THE BULK OF THE INTENSITY GUIDANCE SUGGETS RELATIVELY STEADY BUT SLOW INTENSIFICATION OVER THE NEXT 24 TO 48 HOURS, WHILE THE HWRF SUGGESTS MORE RAPID INTENSIFICATION WITH A TRACK MORE OVER WATER. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.

TRACK GUIDANCE INDICATES A NORTHERLY TRACK OVER THE NEXT 48 HOURS, WITH A POSSIBLE LANDFALL ALONG THE WESTERN PORTION OF THE MYANMAR COAST. THE BULK OF THE INTENSITY GUIDANCE SUGGETS RELATIVELY STEADY BUT SLOW INTENSIFICATION OVER THE NEXT 24 TO 48 HOURS, WHILE THE HWRF SUGGESTS MORE RAPID INTENSIFICATION WITH A TRACK MORE OVER WATER.

THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED NEAR 11.7S 118.7E IS NOW LOCATED NEAR 11.8S 116.4E, APPROXIMATELY 1170KM NORTH-NORTHEAST OF LEARMONTH, AUSTRALIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION WITH IMPROVED CONVECTIVE BANDING. A 191317Z PARTIAL ASCAT PASS REVEALS BROAD EASTERN SWATH OF 20-25 KNOT WINDS WITH POCKETS OF 30 KNOTS WRAPPING INTO A FORMATIVE LLCC. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH RELATIVELY STRONG EQUATORWARD AND POLEWARD OUTFLOW, AND LOW TO MODERATE (10-20 KNOTS) VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES (SST) VALUES (30-31C) ARE CONDUCIVE FOR FURTHER DEVELOPMENT. GLOBAL MODELS INDICATE A WEST- SOUTHWESTWARD TRACK OVER THE NEXT 48 HOURS WITH STEADY DEVELOPMENT. GFS AND HWRF SHOW A SHARP INTENSIFICATION TREND WHILE COAMPS-TC INDICATES A SLOWER INTENSIFICATION TREND. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.

GLOBAL MODELS INDICATE A WEST- SOUTHWESTWARD TRACK OVER THE NEXT 48 HOURS WITH STEADY DEVELOPMENT. GFS AND HWRF SHOW A SHARP INTENSIFICATION TREND WHILE COAMPS-TC INDICATES A SLOWER INTENSIFICATION TREND.

AN AREA OF CONVECTION (INVEST 94S) HAS PERSISTED NEAR 9.0S 92.1E, APPROXIMATELY 630 KM NORTHWEST OF COCOS ISLAND. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 191459Z PARTIAL ASCAT PASS REVEAL AN ELONGATED AND BROAD LLC. UPPER-AIR ANALYSIS SHOWS THAT INVEST 94S IS HINDERED BY HIGH (30-40KT) VWS AND WEAK EQUATORWARD OUTFLOW BUT IS OFFSET BY FAVORABLE (29-30C) SST VALUES. GLOBAL NUMERICAL MODELS AGREE THAT INVEST 94S WILL GRADUALLY DEVELOP AS THE SYSTEM TRACKS WEST-SOUTHWESTWARD BUT IS NOT EXPECTED TO REACH TROPICAL STORM STRENGTH UNTIL BEYOND THE 48-72 HOUR PERIOD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15-20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

GLOBAL NUMERICAL MODELS AGREE THAT INVEST 94S WILL GRADUALLY DEVELOP AS THE SYSTEM TRACKS WEST-SOUTHWESTWARD BUT IS NOT EXPECTED TO REACH TROPICAL STORM STRENGTH UNTIL BEYOND THE 48-72 HOUR PERIOD.