Mother Nature is a beauty but she can turn dangerous in a moment’s notice. There are many different types of severe weather events we can experience ranging from tornadoes and intense winds to torrential rainfall and baseball sized hail. Though rare in NYS, these events are never out of the question when predicting what Mother Nature will throw at us next. How do meteorologists know when and where these events can and will happen? It’s a bit of a complicated answer. Let’s start with the ingredients needed to cook up these kinds of severe weather events.
The four main ingredients can be remembered using the acronym SLIM:
S – Shear
L – Lift
I – Instability
M – Moisture
Shear is short for wind shear which is a change in direction or speed of wind with height. This change in direction and/or speed helps thunderstorms last longer and become more powerful.
Lift refers to some force that will physically make the air rise (lift) which will initiate storms to pop up. Fronts and low pressure systems are just a few examples of mechanisms that can lift air up to start storms.
Instability refers to how unstable the atmosphere is. Think of a giant ball at the bottom of a hill. If you try to give it a light push and let go, it will roll back down to where it originally was so it’s stable. If it’s at the top of the hill, a light push will easily allow it to roll down the hill away from where it started so it would be considered unstable. The more unstable the atmosphere is, the stronger the potential for severe weather to occur.
Moisture is required for any thunderstorm to form and can come from bodies of water such as the ocean.
Meteorologists look to see if all of these ingredients are present in the atmosphere. If they are, we know Mother Nature can cook up some powerful thunderstorms like supercells. This type of thunderstorm is capable of producing strong winds, large hail, heavy rain, and tornadoes all at the same time! These storms pop up fairly randomly, so we can predict with confidence a general area where these storms will hit but the precise location is still a challenge.