How the Term Severe Weather is Officially Defined by Meteorologists

There has been a lot of talk about severe weather events over the last few weeks as typical spring season storms are erupting with more frequency. But what does the term "severe weather" mean specifically? Read on for the details.

Defining Severe Weather

Severe weather can take on many different forms, ranging from flash flooding, frequent lightning strikes, hail, damaging winds, and tornadic activity. While many people throw the term around to describe any type of inclement condition, there are clear distinctions in how meteorologists classify the presence of severe weather.

In general, any type of weather that poses a threat to life and property should be considered severe. This encompasses various acts of Mother Nature that can happen at any time of the year, not just during the spring season.

The National Weather Service (NWS) is the agency charged with issuing alerts to inform people of the risks. For instance, a flash flood warning will be issued when a flooding event is imminent. Likewise, strong winds could trigger a high wind or red flag warning.

As it relates to thunderstorms, there is a specific set of criteria that must be met for an event to fall under the category of severe. One of these criteria is that the hailstones must measure at least a quarter-size in diameter. This equates to a measurement of about 1 inch in diameter or larger.

This measurement for hail has not been pulled out of thin air. The criteria were set at this measurement as this is the size in which hail is likely to cause damage.

The size criteria were smaller before 2010, designated as the size of a penny. However, the parameter was increased after studies indicated that hail smaller than the size of a quarter generally does not inflict significant amounts of damage.