When does a snowstorm become a blizzard?

According to the National Weather Service, a blizzard must meet these conditions for at least a three-hour stretch:

• It must have sustained winds or frequent gusts of 35 miles an hour or greater.

• It must feature large amounts of falling and/or blowing snow that reduces visibility  to less than a quarter mile)

For most people, a memorable snowstorm is measured by the amount of snow on the ground when it wraps up. That number won’t be in till Sunday, but here’s a list of the heaviest snowfalls in the Twin Cities as compiled by the National Weather Service. (Some of these storms may not have qualified as blizzards.)

Top 20 Twin Cities snowfalls

1. 28.4 inches: Oct. 31-Nov. 3, 1991 (Halloween Blizzard)

2. 21.1 inches: Nov. 29-Dec. 1, 1985

3. 20.0 inches: Jan. 22-23, 1982

4. 17.4 inches: Jan. 20-21, 1982

5. 17.1 inches: Dec. 10-11, 2010

6. 16.8 inches: Nov. 11-12. 1940 (Armistice Day Blizzard)

7. 16.7 inches: March 3-4, 1985

7. 16.7 inches: March 11-14, 1940

9. 16.5 inches: Dec. 27-28, 1982

10. 16.0 inches: Jan. 20-21, 1917

11. 16.0 inches: March 8-9, 1999

12. 14.7 inches: March 31, 1985

13. 14.3 inches: Nov. 29-30, 1991

14. 14.1 inches: March 22-23, 1952

15. 14.1 inches: Nov. 27-Dec. 1, 1983

16. 13.8 inches: Feb. 20-21, 2011

17. 13.6 inches: March 22-23, 1966

17. 13.6 inches: April 14, 1983

19. 13.1 inches: Dec. 13-15, 1983

20. 13.0 inches: April 27-28, 1907