In the great plains of the u. s., tornadoes are common in the summer. this is because
continental polar air masses can reach further south
tornadoes get their energy from flat ground
winters are more humid than summers
winds pick up speed more gradually in the summer

I believe the answer is: winds pick up speed more gradually in the summer

The increase of wind speed is related to the temperature. Temperature could influence the motion of the atoms , and the motion tend to be faster in higher temperature. Due to his increase in motion, winds pick up speed more gradually at summer and increase the likelihood of tornadoes from occuring.

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

i think it would be 5