First Alert Weather First Look: Specific probabilities for severe weather

By News10NBC

ROCHESTER, N.Y. – As meteorologists, we find severe weather events fascinating from a scientific standpoint—but no one wants to see tornadoes or damaging storms in their community.

So what exactly prompts a tornado warning?

There are two primary triggers:

  1. Visual confirmation – A trained spotter or law enforcement official reports seeing a funnel cloud or tornado on the ground.
  2. Radar detection – Doppler radar identifies strong rotation within a thunderstorm, suggesting that a tornado may be forming or already occurring.

For this upcoming Tuesday, the Storm Prediction Center (SPC), part of the National Oceanic and Atmospheric Administration (NOAA), is forecasting a heightened risk for severe weather based on the latest computer model guidance. This is classified as a Level 3 out of 5 — known as an Enhanced Risk — for Tuesday afternoon and evening.

Here is what that means in practical terms:

  • There is a 5 percent chance of a tornado within a 25-mile radius of any given point in the risk zone.
  • A 15 percent chance of large hail.
  • And a 30 percent chance of damaging straight-line winds, also within that 25-mile radius.

It’s important to understand the terminology:

  • A Watch means the conditions are favorable — the ingredients are in place.
  • A Warning means severe weather is occurring or imminent.

The best way to remember it? Watch for the Warning.