Tropical Cyclone Activity: Indian Ocean (Update 4)

S Indian Ocean: Storm Alert issued at 2 Jan, 2013 18:00 GMT

Tropical Cyclone DUMILE (07S) currently located near 17.9 S 55.0 E is forecast to strike land to the following likelihood(s) at the given lead time(s):

Red Alert Country(s) or Province(s)
    Reunion
        probability for CAT 1 or above is 45% in about 24 hours
        probability for TS is 90% within 12 hours

Yellow Alert City(s) and Town(s)
    St Pierre (21.3 S, 55.5 E)
        probability for CAT 1 or above is 15% in about 24 hours
        probability for TS is 80% within 12 hours

Note that
    Red Alert (Severe) is CAT 1 or above to between 31% and 100% probability.
    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/

022100Z POSITION NEAR 18.6S 54.9E.
TROPICAL CYCLONE (TC) 07S (DUMILE), LOCATED APPROXIMATELY 200 NM
NORTH OF LA REUNION, HAS TRACKED SOUTHWARD AT 13 KNOTS OVER THE PAST 
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS THAT A 16-NM 
RAGGED EYE HAS DEVELOPED OVER THE PAST SIX HOURS; HOWEVER, WITH THE 
EXCEPTION OF THE EYEWALL CONVECTION, DEEP CONVECTIVE BANDING HAS 
DIMINISHED. A 021628Z SSMIS 37 GHZ IMAGE DEPICTS A MICROWAVE EYE 
FEATURE (BROKEN RING OVER THE NORTH QUADRANT), FRAGMENTED DEEP 
CONVECTIVE BANDING NORTH WRAPPING INTO THE EAST QUADRANT AND TIGHTLY-
CURVED SHALLOW BANDING ELSEWHERE. BASED ON THE IMPROVED EYEWALL 
CONVECTION, THE DVORAK INTENSITY ESTIMATES HAVE INCREASED TO 65 
KNOTS FROM ALL AGENCIES, THEREFORE, THE INITIAL INTENSITY IS 
ASSESSED AT 65 KNOTS. THIS IS CONSISTENT WITH THE RECENT SATCON 
ESTIMATES OF ABOUT 70 KNOTS. THERE IS HIGH CONFIDENCE IN THE INITIAL 
POSITION BASED ON THE EYE FEATURE. TC 07S IS TRACKING JUST WEST OF 
SOUTHWARD ALONG THE WESTERN PERIPHERY OF THE DEEP SUBTROPICAL RIDGE 
(STR) POSITIONED TO THE EAST. THE SYSTEM IS FORECAST TO RECURVE 
AROUND THE STR AND ACCELERATE SOUTHEASTWARD AFTER TAU 36. DYNAMIC 
MODEL GUIDANCE AS WELL AS ENSEMBLE GUIDANCE IS IN TIGHT AGREEMENT 
SUPPORTING THE JTWC FORECAST TRACK WITH HIGH CONFIDENCE. THE RECENT 
FMEE UPPER-AIR SOUNDING ALSO BOLSTERS THE DYNAMIC GUIDANCE SHOWING 
NORTHEAST FLOW AT 25 TO 35 KNOTS, INDICATIVE OF THE STRONG STR AND 
FURTHER SUPPORTING THE WESTWARD BIAS TO THE FORECAST TRACK. TC 07S 
IS FORECAST TO PEAK NEAR 75 KNOTS BY TAU 12 TO 24 DUE TO THE 
FAVORABLE UPPER-LEVEL CONDITIONS. BY TAU 36, THE SYSTEM SHOULD BEGIN 
TO WEAKEN DUE TO INCREASING VERTICAL WIND SHEAR (VWS) AND COOLER SST 
(LESS THAN 25C). TC 07S SHOULD BEGIN EXTRA-TROPICAL TRANSITION (ETT) 
NEAR TAU 48 AND SHOULD COMPLETE ETT BY TAU 72. CONCURRENTLY, 
SIGNIFICANT WEAKENING IS FORECAST DUE TO COLD SST (LESS THAN 20C) 
AND STRONG VWS ASSOCIATED WITH STRONG MIDLATITUDE WESTERLY FLOW 
IMPINGING ON THE SYSTEM. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 021800Z 
IS 28 FEET.

- JTWC, Eumetsat and Tropicalstormrisk