Yellow Alert City(s) and Town(s)
Port Mathurin (19.7 S, 63.4 E)
probability for CAT 1 or above is 10% in about 72 hours
probability for TS is 20% in about 72 hours
Note that
Yellow Alert (Elevated) is CAT 1 or above to between 10% and 30% probability, or TS to above 50% probability.
CAT 1 means Tropical Cyclone strength winds of at least 74 mph, 119 km/h or 64 knots 1-min sustained.
TS means Tropical Storm strength winds of at least 39 mph, 63 km/h or 34 knots 1-min sustained.
For graphical forecast information and further details please visit http://www.tropicalstormrisk.com/
This alert is provided by Tropical Storm Risk (TSR) which is sponsored by UCL, Crawford & Company and the Aon Benfield UCL Hazard Research Centre.
172100Z POSITION NEAR 16.1S 71.1E. TROPICAL CYCLONE 03S (AMARA), LOCATED APPROXIMATELY 544 NM SOUTH OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS IMPROVING STRUCTURE AS THE LOW LEVEL CIRCULATION CENTER (LLCC) HAS BECOME TIGHTER WRAPPED AND DEEP CONVECTION HAS FURTHER IMPROVED. A 171644Z AMSU-B MICROWAVE IMAGE DEPICTS A WELL DEFINED SYSTEM AS DEEP CONVECTION HAS ALMOST COMPLETELY WRAPPED AROUND A MICROWAVE EYE. THE CURRENT POSITION IS BASED UPON THE AFOREMENTIONED IMAGERY WITH HIGH CONFIDENCE. THE CURRENT INTENSITY OF 50 KNOTS IS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES THAT RANGE FROM 45 TO 55 KNOTS. UPPER- LEVEL ANALYSIS INDICATES THE SYSTEM IS NOW LOCATED UNDERNEATH THE SUBTROPICAL RIDGE AXIS WHICH IS PROVIDING LOW (05-10 KNOTS) VERTICAL WIND SHEAR (VWS) AND GOOD EQUATORWARD OUTFLOW ALTHOUGH THE POLEWARD OUTFLOW CHANNEL HAS DIMINISHED. TC 03S CONTINUES TO MOVE SLOWLY AS IT IS LOCATED IN A WEAK STEERING ENVIRONMENT, BETWEEN TWO SUBTROPICAL RIDGES. THE SYSTEM IS EXPECTED TO BEGIN TO SLOWLY ACCELERATE TO THE WEST IN THE NEXT 24 HOURS AND REMAIN ON A THIS SLOW WESTWARD TRACK UNDER THE INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE SOUTHEAST. BY TAU 96 A DEEP MID-LATITUDE TROUGH WILL PASS SOUTH OF THE CYCLONE AND ERODE THE WESTERN PERIPHERY OF THE STEERING SUBTROPICAL RIDGE. DURING THIS TIME TC 03S WILL BEGIN TO SLOW DOWN AND DIP SOUTHWEST. GRADUAL INTENSIFICATION IS EXPECTED UNDER THE FAVORABLE UPPER LEVEL CONDITIONS AS WELL AS SUPPORTIVE 26 TO 27 DEGREE SEA SURFACE TEMPERATURES (SSTS). AS TC AMARA APPROACHES THE WATERS NORTHEAST OF MAURITIUS, THE COMBINED EFFECTS OF WARMER SSTS (28 DEGREES CELSIUS) AND INCREASED POLEWARD OUTFLOW, SHOULD CAUSE INTENSIFICATION TO 75 KNOTS. MODEL GUIDANCE IS IN GOOD AGREEMENT WITH ONLY A 100 NM SPREAD AT TAU 120 BUT THERE REMAINS SOME DISAGREEMENT IN THE ALONG TRACK SPEEDS. THE OFFICIAL FORECAST REMAINS CLOSE TO THE MULTI-MODEL CONSENSUS. LOW CONFIDENCE IN THE FORECAST TRACK REMAINS DUE TO THE SLIGHT SPREAD IN THE MODEL GUIDANCE AND THE COMPLEX STEERING ENVIRONMENT THROUGH THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171800Z IS 13 FEET.
- CIMSS, TSR and JTWC
