Current Southern Hemisphere Tropical Systems: Tropical Cyclone 13S Felleng

020900Z POSITION NEAR 26.5S 51.3E.
TROPICAL CYCLONE (TC) 13S (FELLENG), LOCATED APPROXIMATELY 370 NM
SOUTHWEST OF LA REUNION, HAS TRACKED SOUTHWARD AT 14 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE
SYSTEM HAS BEGUN TO SHOW SIGNS OF ELONGATION AS THE MAIN CONVECTIVE
BANDS ARE DISPLACED EASTWARD OF THE LOW LEVEL CIRCULATION CENTER.
THIS IS ALSO READILY APPARENT ON A 020422Z 37GHZ SSMIS MICROWAVE
PASS. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION AND ON THE
SSMIS IMAGE WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS BASED ON
CONGRUENT DVORAK ESTIMATES FROM PGTW, KNES, AND FMEE. UPPER LEVEL
ANALYSIS INDICATES THE SYSTEM IS SOUTH AND WEST OF A RIDGE AXIS IN AN
AREA OF MODERATE TO STRONG (20-30 KNOT) WESTERLY VERTICAL WIND SHEAR
(VWS). THE CYCLONE IS TRACKING ALONG THE WESTERN EDGE OF A
SUBTROPICAL HIGH (STH) TO THE EAST. A SHORTWAVE TROUGH CURRENTLY
DIGGING THE WESTERN FLANK OF THE SYSTEM IS EXPECTED TO WEAKEN THE STH
AND CAUSE THE CYCLONE TO TRACK ON A MORE SOUTHEASTWARD DIRECTION. AS
TC 13S TRACKS FURTHER POLEWARD, THE STRONG VWS IS EXPECTED TO
GRADUALLY ERODE THE SYSTEM. BY TAU 36, THE CYCLONE WILL COMMENCE
EXTRA-TROPICAL TRANSITION AS IT GETS EMBEDDED IN THE BAROCLINIC ZONE,
BECOMING A GALE-FORCE COLD CORE LOW BY TAU 48. THE AVAILABLE
NUMERICAL GUIDANCE IS IN TIGHT AGREEMENT WITH WBAR ON THE LEFT OF AND
UKMET ON THE RIGHT OF THE MODEL ENVELOPE. THERE IS HIGH CONFIDENCE IN
THE JTWC FORECAST THAT IS LAID JUST TO THE LEFT OF AND SLIGHTLY
FASTER THAN CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020600Z IS
30 FEET.

- JTWC + EUMETSAT