Sunday could be another round of scattered severe storms. Let me emphasize first that this is not going to be a repeat of last Friday's derecho. That is a once, maybe twice in a lifetime kind of event.
What made those storms so strong was incredibly large line (cluster) of strong storms with intense winds. Winds gusts were clocked at 60mph to even 85 mph! With that in mind, a severe storm is classified as severe when winds reach over 58mph. That can still do plenty of damage!
On Friday the Storm Prediction center already has us outlines for a 30% chance of severe storms.
Damaging winds are going to be our most likely threat but large hail isn't out of the question.
Unfortunately, some areas are still without power and many trees are weak due to last week's intense storms.
This line of storms will form ahead of a cold front that will move from north to south of our area through the afternoon on Sunday.
Because of how much heat we've seen lately, and with the forcing behind the front that increases the instability and chances for strong to severe storms.
We also have some pretty strong upper level winds that get transported down to the surface as part of a thunderstorms downdraft. That also helps in creating strong straight line wind gusts.
Here is a look at what we call CAPE, or Convective Available Potential Energy.
This is a measure of instability in the atmosphere from one of our forecast models.
So it's an approximation of potential energy for Sunday afternoon.
This particular forecast model estimates about 3200 to 3500 for the Northern Valley and about 2000 for the Harrisonburg area.
That's quite a bit of instability!! The larger the CAPE , the stronger the updraft, and stronger the storm.
We'll be watching the development of any strong storms closely. The most likely time frame would be in the later afternoon and into the evening hours. Some of this could linger later into the night as the cold front slowly moves through the region and parks itself to the south for the next few days.
Remember if we do feel the threat is great enough, we will try to give you as much of advance notice as we can and issue a Severe Weather Alert Day. Reminding you to stay with TV3 thorughout the afternoon and evening for the latest updates.