logo
What is a SPC Category?
news image
Top Stories
22 May 2020 7:28 AM
https://www.facebook.com/WeatherNation/videos/2108223926064990/ Marginal Risk, Slight Risk, Moderate Risk…terms we use as meteorologists to signify a Severe Weather Day for you. These forecasts come from the Storm Prediction Center (SPC), located in Norman, Oklahoma. There are five severe thunderstorm risk categories, all relating to the probability of a severe weather event within 25 miles of any given location. The outlook also factors in how widespread or intense an event might be. A severe thunderstorm is defined by the National Weather Service as one with measured wind gusts at least 58 miles per hour, hail at least one inch in diameter, and/or a tornado. A Marginal Risk means storms could be spotty, and typically will be limited in duration and/or intensity. Even though this threat level is on the lower end, you should still take it seriously:  tornadoes, damaging wind, and large hail are all possible. A Slight Risk means scattered powerful thunderstorms are expected. While storms may be short-lived, they can be intense. Within the risk area, storms could produce tornadoes as well as isolated areas of wind or hail damage. An Enhanced Risk means numerous severe storms are expected over the risk area. Coverage of storms will be more widespread than the previous threat levels, once again, hail, wind damage, and tornadoes are possible. A Moderate Risk means severe thunderstorms will be more widespread within the area, potentially longer-lived storms, and even more intense than the first three categories. A day with a moderate risk level on the SPC scale often holds potential for strong or long lived tornadoes, and extensive wind or hail damage. Then, there’s the fifth category,  High Risk. This threat level is not common -- it is the most severe and should be taken very seriously. Storms could potentially bring catastrophic damage. In high risk days, strong, long track tornadoes are possible, as well as widespread damaging winds or extremely large and damaging hail. Just remember, severe storms can happen anywhere, any time of day. That’s why it’s important to always stay with WeatherNation when there’s even the slightest threat for severe weather in your neighborhood.. For WeatherNation, I'm Meteorologist Meredith Garofalo
All Weather News
California Snowpack - More than Double of Normal, with More Snow Ahead Tonight
California Snowpack - More than Double of Normal, with More Snow Ahead Tonight
Snowpack statewide is over double the normal,
20 Mar 2023 2:20 PM
After a Brutally Cold Weekend in the South, Relief is in Sight this Week
After a Brutally Cold Weekend in the South, Relief is in Sight this Week
What a cold weekend in the Southeast and now,
20 Mar 2023 2:10 PM
Four Corners: More Rain and Snow
Four Corners: More Rain and Snow
The system bringing rain and snow to Californ
20 Mar 2023 2:00 PM
Severe Storm Chances Return to the Plains & South Late Week
Severe Storm Chances Return to the Plains & South Late Week
A strong low-pressure system moving into Cali
20 Mar 2023 1:50 PM
Next Round of Winter Alerts for the Northern Plains
Next Round of Winter Alerts for the Northern Plains
Winter alerts are once again in effect for th
20 Mar 2023 1:40 PM
Lake Effect Snowfall Wrapping Up
Lake Effect Snowfall Wrapping Up
We're wrapping up the final weekend of winter
19 Mar 2023 6:50 PM
In Florida for Vacation? Additional Rain Overnight
In Florida for Vacation? Additional Rain Overnight
Florida. The Sunshine State. Usually, that's
19 Mar 2023 6:20 PM