A VIGOROUS TROPICAL DISTurbineCE LOCATED OVER THE NORTHWESTERN CARIBBEAN SEA IS BECOMING BETTER ORGANIZED. ALTHOUGH THERE DOES NOT APPEAR TO BE A CLOSED SURFACE CIRCULATION AT THIS TIME...NEARBY SHIP AND BUOY OBSERVATIONS INDICATED WINDS OF TROPICAL-STORM-FORCE BRIEFLY OCCURRED IN ASSOCIATION WITH THIS SYSTEM DURING THE PAST FEW HOURS. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR DEVELOPMENT OF THIS DISTurbineCE AS IT MOVES GENERALLY WEST-NORTHWESTWARD AT 10 TO 15 MPH...AND A TROPICAL DEPRESSION COULD DEVELOP DURING THE NEXT COUPLE OF DAYS. THERE IS A MEDIUM CHANCE...50 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.