There has been a lot of talk about SUNDAY'S potential for severe weather, but the potential for severe strorms with strong damaging wind and even isolated tornadoes is actually higher in some respects Saturday evening into Saturday night. Both days this weekend will likely be active as waves of upper energy move over the muggy and very warm air near the surface ahead of a cold front.
You can already feel the humidity outside, and the heat will be with it Saturday, with highs pushing 90 in some spots by mid afternoon. All of that heat and humidity is energy for any storm to get going. (These values are known as CAPE, which stands for Convective Available Potential Energy. The values Saturday afternoon and evening into Sunday suggest severe weather.)
There wil be enough wind shear in place for rotating storms - supercells. Not everwhere, but some of the more severe storms that tap into the shear become supercells. Supercells can produce damaging winds, very large hail, and tornadoes. So, this is something to watch closely. This may be esepcially true SATURDAY EVENING AND NIGHT, though we need to watch Sunday as well.
SATURDAY 3 p.m. into SATURDAY NIGHT / EARLY SUNDAY from west to east for everyone.
SUNDAY along and EAST of the Blue Ridge Parkway from NOON to around 6 p.m.
The storms will likely arrive in several clusters.
By definition, a severe thunderstorm produces one or more of the following:
HAIL at least 1" in diameter or greater
WIND GUSTS to 58 mph or greater (can be straight-line winds)
These are ALL possibilities in the setup we are in this weekend.
Remember, a Severe Thunderstorm or Tornado WATCH is issued when conditions are favorable for severe storms and/or tornadoes.
A Severe Thunderstorm or Tornado WARNING is issued when the danger is immenent for your area.
You may see a lot of these alerts this weekend. Take some time to read over them, and know what they mean. Don't forget about when the warnings are issued and when they expire! I'm set up on social media to auto-post watches and warnings. However, a lot of folks will "like" or comment on an alert that was issued a long time ago. Just remember to read over EVERYTHING and be aware of the timestamp and experation time. It may be in your newsfeed, but that doesn't necessarily make it current.
Also, don't forget about lightning and flash flooding. ANY storm can produce dangerous lightning. Remember, if you can hear thunder, you need to go inside. Even if the sky is blue, lightning can strike up to 25 miles AWAY from the storm!
Flash flooding is very dangerous. Move to higher ground if a Flash Flood Warning is issued for your area and NEVER drive across a flooded road! TURN AROUND, DON'T DROWN.
WHAT TO DO IF A WARNING IS ISSUED FOR YOUR AREA (from the NWS)
- The best defense against thunderstorms is to stay inside a sturdy building or shelter that can protect you from deadly lightning, large hail, damaging winds, flooding rain and tornadoes. Fortunately, thunderstorms typically do not last very long and will most often pass by your location in less than one hour.
- Once in a shelter, stay away from windows and avoid electrical equipment and plumbing. Remember to bring pets inside. If there is time, secure loose objects outside as these objects often become dangerous flying debris in high winds.
- Postpone outdoor activities until the storms have passed.
- If caught outside, take shelter in a sturdy enclosed building or hard top automobile immediately. Avoid open spaces, isolated objects, high ground and metallic objects.
- Get out of boats and away from bodies of water. Remember, if you can hear thunder, you are close enoughto the storm to be struck by lightning.
If a tornado is spotted, act quickly and move to the lowest level basement of your shelter, putting as many walls between yourself and the outside as possible.
IF A TORNADO WARNING IS ISSUED FOR YOUR AREA: Move fast, but don't panic. Get into a basement, or as low as you can. If you don't have a basement, go into a windowless closet or hallway on the lowest level. Get under a table or work bench if possible. Abandon mobile homes, they are not safe during a tornado. Make plans to stay with someone - a neighbor, friend or relative with a sturdy shelter before the storm. If caught outside, get into a ditch. Again, the lowest spot you can find. Do not crouch under a highway overpass. Winds are actually higher there in a tornado.
I'll have updates all weekend. Be safe and aware!