The new models are out, and they are beginning to hint at lower severe weather probabilities for this evening. We still may see a thunderstorm or two, but the chances of any local storm reaching severe criteria is small. So, what makes a storm a severe storm? Well, for the title to be achieved, two of the these three criteria must be met:
1. Winds 58mph or better
2. Hail the size of a quarter or bigger (greater than or equal to 1″ in diameter)
3. Any tornadic activity (funnel cloud/tornado)
The Storm Prediction Center
The Storm Prediction Center (SPC), located in Norman, Oklahoma, is tasked with forecasting the risk of severe thunderstorms and tornadoes across the United States. The agency issues convective outlooks, mesoscale discussions, and watches as a part of this process.
This year, the convective outlook product has taken on a new look, as the SPC decided to expand upon their prediction classification system. In the past, the threat for severe weather was either labeled slight, moderate, or high. This severe weather season, you will notice two more classifications; ENHANCED and MARGINAL.
So, if you see, for example, an enhanced risk area over your community, what does it mean?? Well, here is a breakdown:
1. Marginal/dark green risk area – Includes severe storms of either limited organization and longevity, or very low coverage and marginal intensity.
2. Slight/yellow risk area – Implies organized severe thunderstorms are expected, but usually in low coverage with varying levels of intensity.
3. Enhanced/orange risk area – Depicts a greater concentration of organized severe thunderstorms with varying levels of intensity.
4. Moderate/red risk area - Indicates potential for widespread severe weather with several tornadoes and/or numerous severe thunderstorms, some of which may be intense.
5. High/magenta risk area - Suggests a severe weather outbreak is expected from either numerous intense and long-track tornadoes, or a long-lived derecho system with hurricane-force wind gusts producing widespread damage.
**The light green area above is labeled “TSTM” for “Thunderstorm.” This area indicates a 10% or higher probability of thunderstorms forecast during the valid period.**
Now that the Spring season is upon us, don’t forget to download our KXAN Severe Weather Guide!! It’s a great refresher in case you and your family get caught in a severe weather situation.