May is the peak month for Tornadoes in the Miami Valley. The state of Ohio sees an average of 4 tornadoes during May.
Even though this is the peak month, a tornado is still rare. The atmospheric conditions have to be just right.
There are four main ingredients meteorologist look for when forecasting severe weather, moisture, shear, lift, and convective available potential energy.
A tornado must have shear to form. Shear refers to the change in wind with height. There are two types of wind shear meteorologists look for.
Speed Shear: Wind speed increases with height
Directional Shear: Wind direction changes with height.
Many times storm development will start with speed shear. As the wind speed increases with height, a horizontal rotating column of air will start to spin.
For a storm to develop you will need the other three ingredients. CAPE refers to rising warm air. Sometimes the heat from the sun is enough to get air at the surface to rise. Sometimes there needs to be additional lift from a front. It is difficult for air to rise with out moisture.
From there the rising air will start to stretch and tilt the rotating column of air vertical. This is how an updraft will develop. Directional wind shear is key to keeping the column of air rotating. As the updraft strengthens and column of air will stretch and a Tornado can develop.
QUESTION: How can a make a tornado?
HYPOTHESIS: If I spin a jar around, then a tornado will form.
MATERIALS: Jar, lid, water, (extras: dish soap, vinegar, food coloring, glitter)
Find a jar with a lid that fits.
Clean the jar.
Add water up to 3/4 to the top of the jar.
Add any of the extras you wish.
Put the lid on the jar tightly.
Hold the jar near the lid with one hand.
Circle your wrist to spin the water in the jar.
OBSERVATION: Watch the tornado develop with the shear you created.
CONCLUSION: The way you spin the lid will cause the water to rotate at different speeds. This simulates the rotating column of air. A tornado will develop in the simulated shear.