212100Z POSITION NEAR 32.2S 40.5E.
TROPICAL CYCLONE 15S (GUITO), LOCATED APPROXIMATELY 850 NM
SOUTH-SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED
SOUTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED
SATELLITE IMAGERY REVEALS AN ELONGATING LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH FLARING CONVECTION ALONG THE SOUTHERN SEMI-CIRCLE. A
211555Z TRMM 37 GHZ MICROWAVE IMAGE CONTINUES TO INDICATE A TIGHTLY-
WRAPPED SYSTEM WITH CONVECTIVE BANDS ALONG THE SOUTHWESTERN QUADRANT
WHILE DRY AIR IS BEGINNING TO WRAP IN FROM THE NORTHERN PERIPHERY.
THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED ON THE
AFOREMENTIONED IMAGERY. THE INITIAL INTENSITY IS ASSESSED AT 45
KNOTS BASED ON THE CURRENT STRUCTURE AND CONGRUENT DVORAK CURRENT
INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES. TC 15S IS TRACKING
ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP LAYER SUBTROPICAL RIDGE
(STR) LOCATED TO THE NORTHEAST AND IS FORECAST TO ACCELERATE
SOUTHEASTWARD AS IT BEGINS EXTRA-TROPICAL TRANSITION (ETT) WITHIN
THE NEXT 12 HOURS. TC GUITO IS EXPECTED TO COMPLETE ETT BY TAU 36 AS
IT BECOMES EMBEDDED WITHIN THE MIDLATITUDE WESTERLIES AND GAINS
FRONTAL CHARACTERISTICS. THERE IS A POSSIBILITY THAT THE SYSTEM MAY
WEAKEN BELOW WARNING THRESHOLD (35 KNOTS) BEFORE COMPLETING ETT. DUE
TO THE TIGHT AGREEMENT IN DYNAMIC MODEL SOLUTIONS, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 211800Z IS 18 FEET.
- JTWC
