WTIO30 FMEE 090045 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 6/12/20142015 1.A MODERATE TROPICAL STORM 12 (HALIBA) 2.A POSITION 2015/03/09 AT 0000 UTC: WITHIN 20 NM RADIUS OF POINT 21.0 S / 53.5 E (TWENTY ONE DECIMAL ZERO DEGREES SOUTH AND FIFTY THREE DECIMAL FIVE DEGREES EAST) MOVEMENT : EAST-SOUTH-EAST 11 KT 3.A DVORAK ANALYSIS: 3.0/3.0/D 1.0/24 H 4.A CENTRAL PRESSURE: 994 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT RADIUS OF MAXIMUM WINDS (RMW) :46 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 80 SE: 80 SW: 70 NW: 60 34 KT NE: 60 SE: 60 SW: 60 NW: 60 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 400 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2015/03/09 12 UTC: 21.8 S / 55.5 E, MAX WIND=040 KT, MODERATE TROPICAL STORM 24H: 2015/03/10 00 UTC: 22.7 S / 57.2 E, MAX WIND=035 KT, MODERATE TROPICAL STORM 36H: 2015/03/10 12 UTC: 23.5 S / 58.3 E, MAX WIND=035 KT, MODERATE TROPICAL STORM 48H: 2015/03/11 00 UTC: 24.3 S / 58.6 E, MAX WIND=035 KT, POST-TROPICAL DEPRESSION 60H: 2015/03/11 12 UTC: 24.3 S / 58.0 E, MAX WIND=035 KT, POST-TROPICAL DEPRESSION 72H: 2015/03/12 00 UTC: 23.9 S / 58.8 E, MAX WIND=030 KT, POST-TROPICAL DEPRESSION 2.B LONGER-RANGE OUTLOOK : 96H: 2015/03/13 00 UTC: 26.5 S / 64.1 E, MAX WIND=035 KT, POST-TROPICAL DEPRESSION 120H: 2015/03/14 00 UTC: 33.1 S / 71.1 E, MAX WIND=040 KT, EXTRATROPICAL SYSTEM 2.C ADDITIONAL INFORMATIONS: T=CI=3.0-. THE SYSTEM SHOWS AN IRREGULAR CDO-LIKE PATTERN ON IR IMAGERY WITH AN AVERAGE DIAMETER OF 90 NM. BASED ON VARIOUS SATELLITE ESTIMATES (KNES AT 3.0, PGTW AT 2.5 AND ADT AT 3.1) THE INTENSITY IS RAISED AT 40 KT. MSLP ESTIMATE IS SUPPORTED BY OBS FROM BUOY 56906 WHICH REPORTED AT 23Z A CORRECTED SLP AT 996.7 HPA OVER THE OUTER EDGE OF THE RMW IN THE SOUTH-WESTERN QUADRANT. THE CURRENT POSITION IS BASED ON RADARS DATA FROM LA REUNION. THE SYSTEM IS EXPECTED TO CONTINUE TO TRACK EAST-SOUTH-EASTWARDS WITHIN A WEST TO WESTERLY STEERING FLOW DRIVEN BY THE LOW TO MID-LEVEL NEAR EQUATORIAL HIGHS. WEDNESDAY, THE SYSTEM SHOULD SLOW DOWN WHEN THE REMNANTS OF EX-TROPICAL DEPRESSION 11 ARE EXPECTED TO MERGE WITHIN THE CIRCULATION. A SMALL LOOP, SUGGESTED BY SOME GUIDANCE, IS EVEN POSSIBLE. BY THAT TIME SOME DEEP STRUCTURE CHANGES ARE EXPECTED TO OCCUR WITH A LARGER AND MORE ASYMMETRICAL WIND FIELDS SUGGESTING THAT THE SYSTEM MAY LOOSE ITS PURE TROPICAL CHARACTERISTICS BY THAT TIME. THURSDAY, THE SYSTEM SHOULD RESUME ITS SOUTHEASTWARDS TRACK WITH AN ONGOING EXTRATROP PROCESS. THE ENVIRONMENTAL CONDITIONS ARE STILL RATHER GOOD WITH GOOD OHC, GOOD UPPER LEVEL DIVERGENCE OVER THE NORTHEASTERN QUADRANT (BUT POOR OVER THE SOUTHWESTERN QUADRANT) AND LOW SHEAR JUST TO THE SOUTH OF THE UPPER LEVEL AXIS. THESE CONDITIONS ARE EXPECTED TO SLIGHTLY DETERIORATE LATER TODAY WITH AN INCREASE OF THE WESTERLY SHEAR. THE LOW LEVEL ORGANISATION OF THIS TINY SYSTEM MAY ALSO BE IMPACTED AS THE SYSTEM WILL PASS CLOSE TO LA REUNION. GIVEN THE ONGOING AND EXPECTED IMPACT OF THIS SYSTEM OVER PORTIONS OF THE MASCARENES ISLANDS (MAINLY REUNION ISLAND TOMORROW), INHABITANT OF THIS AREA SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.=