well tornadoes can happen anywhere any time so yes
Blizzards and Tornadoes.
Tornadoes happen in all seasons but are most common in the spring.
That is difficult to determine. Since individual towns are small targets tornado activity tends to be sporadic. Since records began in 1950 there have been 4 recorded tornadoes in Thornton, all in a period running from the early '80s to the mid '90s This results in a frequency of tornadoes somewhere between once every 4 years and once every 15 years.
There were 21 confirmed tornadoes in Colorado in 2011.
It depends on where you live. In the south tornadoes usually occur in late winter, spring and summer. In the north tornadoes usually happen during the late spring and summer. Overall tornadoes can happen at any time of year.
There were 11 confirmed tornadoes in Colorado in 1966. The actual number of tornadoes was probably much higher as at this point the majority of F0 tornadoes (which account for about 60% of all known tornadoes today) were missed.
Tornadoes in Arizona and the southwestern states are rare, but do sometimes happen in the powerful spring and fall "monsoon season" thunderstorms. Arizona averages between 4 and 5 tornadoes per year. Nearly all of these are rated F0, causing little or no damage.
Tornadoes can happen in any place that gets thunderstorms.
Tornadoes happen every year.
Yes. Eastern Colorado actually gets a fairly high number of tornadoes.
You will need to be more specific, there have been many tornadoes in Colorado.
Tornadoes happen in Miami for the same reason they happen anywhere else. See the related question for how tornadoes form in general.