These storms can have maximum winds extending further from the center than in a purely tropical cyclone. The maximum recorded wind speed for a subtropical storm is 33m/s, 119km/h, 65 knots, or 74 MPH), also the minimum for a hurricane. In the Atlantic Basin, the United States NOAA classifies subtropical cyclones just as with tropical ones, based on maximum sustained surface winds: below 18m/s, 65km/h, 35 knots, or 39 MPH is a tropical or subtropical depression, and at or above this velocity is a tropical or subtropical storm.
Subtropical cyclones are also somewhat more likely to form outside of a region's hurricane season, as was the case with Subtropical Storm Ana (which became Tropical Storm Ana) in mid-April of 2003.
Since 2002, the U.S. National Hurricane Center gives numbers to subtropical depressions and names to subtropical storms from the same sequence as tropical ones. Previously, separate numbers were given to subtropical depressions, and were named with that number upon reaching subtropical storm status (that is to say, Subtropical Depression 2 became Subtropical Storm Two, even if S.D. 1 never became S.S. One).