I want to give a detailed description of my thoughts on the potential for severe weather on Thursday. If you’d like to skip over the “why,” scroll to the bottom of this article. I’ve listed my thoughts on the timing and threat.
Showers and thunderstorms started to develop overnight Wednesday into Thursday morning. A cluster of non severe thunderstorms passed through the Stateline early this morning between 3AM and 7AM, with heavy rain as the main threat. Now, we’ve got a break in the heavy rain and thunderstorms this morning. We’ll likely see another round of non severe thunderstorms and showers pass through in the late morning and early afternoon.
The threat of severe thunderstorms doesn’t come in until we head into the mid afternoon and into the evening. However, there are some question marks.
One of the biggest reasons has to do with something meteorologists refer to as instability, which is one of the key ingredients to produce a severe thunderstorm. Have you ever noticed that most thunderstorms occur in the late afternoon? That’s because of daytime heating. All day long, the sun heats up the surface and creates a big difference between the temperature around us and the temperature in the mid levels of the atmosphere. This helps to create more instability. Overnight, there is no sunshine to warm the surface, therefore instability is limited. This is one reason why the threat of severe thunderstorms overnight and early this morning was very minor.
Cloud cover is going to stick around early and late Thursday morning. The thick clouds will limit the amount of sun allowed to heat the surface, which will also limit the amount of instability in the atmosphere. This is the big question mark- will the clouds break in the afternoon, before thunderstorms devlop? IF they do, we run a higher risk of seeing severe thunderstorms. As of this morning, much guidances suggests clouds will start breaking after the lunch hour, which will allow the sun to help increase instability and raise the potential for thunderstorms to turn severe as we head into the mid afternoon through the evening.
The other ingredients we look for as necessary for severe development look to be in place. This includes a strong southerly surface wind, that changes direction as you go up into the atmosphere. Dewpoints reaching the low to middle 60’s combined with an incoming cold front will aid in development of scattered thunderstorms.
I think the biggest threat today will be damaging winds, followed by large hail. I expect discrete thunderstorms to turn severe in the mid afternoon, lasting into the evening. There’s also a risk for a few isolated tornadoes to occur across and near the Stateline.
It is important to know your safe place today, whether you are at home, in school, at work, or driving.
Be sure to have your NOAA Weather Radio working today and do not rely solely on outdoor warning sirens.
Chief Meteorologist Alex Kirchner, 13 Weather Authority’s Nick Jansen and myself will be in through the afternoon and evening to track the thunderstorms and update you on the risk for severe thunderstorms.
Posted under weather
This post was written by Morgan Kolkmeyer on April 9, 2015