Early and Late Season Tornadoes

Early and Late Season Tornado Events

While tornadoes can occur during any month of the year given the right combination of atmospheric parameters, the tables below illustrate that tornado activity in the Tri-State region is rare to non-existent during the colder months. The earliest tornado on record (spring season) occurred on March 8, 1992 when an EF0 tornado developed in Dundy county, Nebraska. Most of the early season tornadoes have occurred in late March. While tornado records since 1950 are fairly reliable, information prior to that is less certain. In his book, Significant Tornadoes 1680-1991, Thomas Grazulis extensively researched tornadoes prior to 1950, documenting significant tornadoes (EF2-EF5).

In the first table below, early season tornadoes are listed. Since the only accurate compilation of tornadoes prior to 1950 are those rated EF2 and above, there may in actuality be additional tornadoes which have occurred in March and April. All tornadoes prior to 1950 are shaded in yellow to highlight this fact. Event totals for these events are not given, since it is unknown what the total number of tornadoes may have been.

Earliest Tornadoes (Mar-Apr) in the Tri-State Area ... 1882-2007

#	Date	County	Num - FScale	Event Total
1	03/08/1992	Dundy	1-F0	1
2	03/13/1973	Sherman	1-F1	1
3	03/24/2007	Yuma	1-F0	1
4	03/25/1980	Cheyenne, CO	1-F1	1
5	03/25/1995	Wichita	1-F0	1
6	03/28/1981	Logan Sheridan	1-F1 1-F1	2
7	03/28/1993	Decatur Norton	1-F0 2-F1	3
8	03/28/2007	Dundy Wallace Decatur Sherman Greeley Cheyenne, KS	1-F1 3-F0, 1-F1 1-F0 5-F0, 1-F2 2-F0, 1-F1 1-F0, 2-F1, 1-F2	16
9	03/31/1954	Yuma	1-F?	1
10	04/08/1978	Red Willow	1-F?	1
11	04/10/2005	Graham	1-F0, 1-F1	2
12	04/12/1941	Sherman Wallace Dundy	1-F2 1-F3 2-F2
13	04/14/1998	Decatur	1-F0, 3-F1	4
14	04/19/1957	Hitchcock	1-F1	1
15	04/19/1979	Graham	1-F2	1
16	04/19/1997	Logan	1-F0	1
17	04/20/1885	Decatur	1-F2
18	04/20/1974	Rawlins	1-F1	1
19	04/22/1957	Kit Carson Hitchcock	1-F2 1-F?	2
20	04/23/1922	Wichita	1-F2
21	04/23/1989	Norton	3-F0	3
22	04/25/1882	Dundy	1-F2
23	04/25/1990	Gove Red Willow	1-F0 1-F0	2
24	04/26/1938	Kit Carson Graham	1-F2 1-F2
25	04/27/1912	Red Willow	1-F2
26	04/27/1958	Rawlins	1-F2	1
27	04/28/1884	Decatur	1-F2
28	04/28/1940	Norton	2-F2
29	04/28/1947	Sheridan-Thomas	F3
30	04/29/1942	Decatur	F5
31	04/29/1997	Thomas	1-F0	1
32	04/30/1906	Decatur	F3

Yellow shading represents data prior to 1950 and only includes significant tornadoes (EF2+).
Since 1950, for dates April 30 or earlier, there have been 21 tornado days (producing 47 tornadoes).
Since 1882, for dates April 30 or earlier, there have been at least 32 tornado days.

Late season tornado events are shown below. The only tornado on record in November in the Tri-State area occurred in Yuma county Colorado in 1922. That fact is interesting enough, but considering the tornado occurred at 9:30 in the morning makes the event even more noteworthy. Once again, only those tornadoes rated EF2 and above are included prior to 1950, and are highlighted in yellow.

Latest Tornadoes (Oct-Nov) in the Tri-State Area ... 1882-2007

#	Date	County	Num-F Scale	Event Total
1	11/04/1922	Yuma	1-F3	1
2	10/31/2000	Decatur Rawlins Sheridan-Thomas-Decatur Sherman Thomas Wallace-Sherman Red Willow	1-F1 1-F0 1-F0 2-F0, 1-F2 1-F0 1-F1 2-F0	10
3	10/29/1956	Thomas	1-F2	1
4	10/28/2000	Gove Graham Norton Sheridan	2-F1 2-F0 1-F0 1-F0	6
5	10/20/1963	Yuma	1-F1	1
6	10/17/1971	Cheyenne, KS Rawlins Yuma	1-F2 1-F3 1-F2	3
7	10/11/1997	Kit Carson	1-F1	1
8	10/08/1997	Kit Carson Yuma	2-F0 2-F0	4
9	10/05/1994	Cheyenne, CO Kit Carson	1-F0 1-F0, 1-F1, 1-F2	4

Yellow shading represents data prior to 1950 and only includes significant tornadoes (EF2+).
Since 1950, for dates October 1 or later, there have been 8 tornado days (producing 30 tornadoes).
Since 1882, for dates October 1 or later, there have been at least 9 tornado days.

NOAA National Weather Service Weather Forecast Office