042100Z POSITION NEAR 27.1S 51.5E.
TROPICAL CYCLONE (TC) 06S (BEJISA), LOCATED APPROXIMATELY 401 NM
SOUTH-SOUTHWEST OF ST DENIS, LA REUNION, HAS TRACKED SOUTHWESTWARD
AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A WELL-STRUCTURED SYSTEM WITH
SHALLOW CONVECTIVE BANDING TIGHTLY WRAPPED INTO A PARTIALLY-EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC). A 041431Z TRMM 85 GHZ MICROWAVE
IMAGE ALSO REVEALS THE DEEP CONVECTION OVER THE SOUTHERN SEMI-CIRCLE
HAS REMAINED TIGHTLY CURVED DESPITE A CONTINUED WEAKENING OF THE
CONVECTION. THE CURRENT POSITION IS BASED ON THE PARTIALLY-EXPOSED
LLCC SEEN IN THE MSI ANIMATION WITH GOOD CONFIDENCE. THE INITIAL
INTENSITY OF 45 KNOTS IS BASED ON THE DVORAK CURRENT INTENSITY
ESTIMATE OF 45 KNOTS FROM KNES. UPPER-LEVEL ANALYSIS INDICATES THE
SYSTEM IS LOCATED WITHIN A MARGINAL ENVIRONMENT AS MODERATE (15 TO
20 KNOTS) VERTICAL WIND SHEAR (VWS) CONTINUES TO HAMPER THE EFFECTS
OF OVERALL GOOD POLEWARD OUTFLOW, WHICH IS EVIDENT IN WATER VAPOR
IMAGERY. TC 06S IS CURRENTLY TRACKING SOUTHWESTWARD ALONG THE
WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE TO THE EAST AND IS
EXPECTED TO REMAIN ON A SOUTHWESTWARD TRACK THROUGH THE REMAINDER OF
THE FORECAST PERIOD. THE COMBINED EFFECTS OF COOL SEA SURFACE
TEMPERATURES AND INCREASING VWS WILL CONTINUE TO WEAKEN TC 06S AND
THE SYSTEM IS EXPECTED TO DISSIPATE BY TAU 36. DUE TO THE GOOD
AGREEMENT AMONG THE MODEL GUIDANCE THROUGHOUT THE FORECAST PERIOD,
THERE IS OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH
IS POSITIONED CLOSE TO THE MULTI-MODEL CONSENSUS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 041800Z IS 15 FEET.
- JTWC
