We have plenty of information for you on tomorrow’s thunderstorms, but first…let’s get you through today.
Today – Cloudy and Waaaaay Warmer Than We Should Be – 67°
We’ll catch a break from the rain today, as the bulk of it moves east.
A stalled cold front will keep clouds around today, with highs in the mid to upper 60°s.
Dew points will climb into the 60°s today, setting the stage for tomorrow’s severe weather threat.
Lows tonight will drop to near 60°.
Rain will return during the overnight hours, with some thunderstorms possible:
However, this will not be the round of severe weather we are concerned about for tomorrow. Other than a few rumbles of thunder, things will be fine to start the day on Wednesday.
Wednesday – Significant Severe Weather Forecast – High: 73°
Yesterday, David mentioned that this forecast could change. We have been hoping it would. Unfortunately, it did change…we are more under the gun than we were yesterday. (And, yes, it could change again).
Here’s the most recent severe thunderstorm risk outlook from the SPC, in the usual colors we show you quite often:
We are included in the ENHANCED risk area, which stretches from the MS River over to just east of us. This is a 3 on a 0-5 scale, if you want to think of it that way. (Editor’s Note: Moderate and High risks the day before an event are almost without precedent. 3 is pretty high the day before, y’all).
And, here’s the companion probabilistic outlook, which pretty much just adds percentages to the mix:
First – the red area: we are included in the red shaded area, which means we have a 30% chance for severe weather within 25 miles of us tomorrow.
Second – the black hatched (dashed lines) area inside the red area: this means that we also have a 10% chance of significant severe weather within 25 miles of us tomorrow.
The black hatched area isn’t brought out all that often, so that solidifies what we already were thinking: tomorrow is looking serious.
What Are We Talking About Here?
The setup causing all this commotion is one that just so happens to have all the right ingredients coming together at the same time: upper-level and surface forcing & dynamics, incredibly humid & warm air aloft and at the surface to work with, and an environment (ours) conducive to producing powerful thunderstorms.
Tomorrow is always a busy, busy day for us all. You probably have travel and/or shopping plans.
Well, I’ll cut straight to the point for you. We are talking about numerous severe thunderstorms possible, capable of producing damaging winds, extremely heavy rainfall, and hail. Some of these storms will be supercell thunderstorms, which have the potential to drop tornadoes – perhaps, as SPC pointed out, some significant tornadoes.
When and Where?
As mentioned earlier, there will be some storms in the morning, but that won’t be the “big show”:
These storms could be strong, though, and maybe even severe. They’ll push through early, 5-8 AM ish.
Then, we’ll need to be watching storms pushing in from both the south and the west for essentially the rest of the day.
I don’t want to throw specific timing out just yet. We’ll need to watch how the models are handling the timing to see if there is some consistency. Also, real-time radar trends tomorrow morning will be key in seeing how things are going.
What has been, and still is, consistent as far as timing goes is that this will generally be an afternoon/evening event for us.
Here’s 1 PM as it stands now:
We likely won’t see things come to an end until a few hours after dark, or maybe into the overnight hours.
What Does All of This Mean?
Models, like the one I shared above with you, suggest a more cellular storm mode, which means more individual storm activity, like supercells (as opposed to a long line of storms). While a line of storms can produce tornadoes, it is most always the supercell thunderstorms that produce the tornadoes we remember.
Our atmosphere is ready to support severe weather. It is abnormally warm, and moisture has been on the increase. The things we can’t see or feel are also there: high CAPE (storm fuel) and shear (the stuff that make storms rotate).
We need to be ready tomorrow. You probably hear all the time that you “need to have a severe weather plan ready.” Well, you really do. I am confident that you reading this take the weather seriously, and are probably prepared. But, on the chance you’re not, take some time today to get ready.
Make sure you know the following: 1) Where you will go if you get a severe weather warning – down to the basement, to a tornado shelter, the most interior room of your home, etc.
2) What you will bring with you – a pre-packed bag for infants or small children, a wireless phone charger, your weather radio, etc.
3) How you will get severe weather alerts – whether it is your weather radio or an app on your phone, make sure you have something that will make an obnoxious noise at you when there is a warning for your area.
For more on this, see this page.
Editor’s Note: Severe weather is expected in somewhere in Middle Tennessee. Whether it hits your town, or your house, or delays your flight — that’s not knowable right now. The hassle to get ready for this event is worth the relatively low risk of an potentially dangerous event.
I was talking to a friend at our local NWS office. He pointed out a few things, all of which Kaiti shared above. One thing to add to it — if the forecast verifies, and we see supercells moving from the SW to the NE, we think they’ll be moving around 60 MPH. When the warning is issued, you’ll already be out of time to prepare. Add to that the likelihood the storms will be coming in the dark – you won’t see them coming.
If that’s alarming, maybe this will calm you down a bit — an event like this seems like a bad one for the Spring. Having an event show its teeth at us like this a few days before Christmas is largely without precedent. So, either it’ll be the first time, or there’s a reason why it’s without precedent. So much uncertainty remains.
So, take a deep breath, have a plan, and stay tuned to multiple reliable sources of weather information. Be sure to tune into your favorite local TV weather team tonight (2, 4, 5, and/or 17) and through the even tomorrow. You can find more info from us on Twitter @NashSevereWx.
Remember, we do not post Warnings to this website, but they auto-post to our Twitter account. You are encouraged to check out the app banner at the bottom of this page.
If you have plans to travel tomorrow by car, I would try to get it done today – if that’s at all possible. You’ll run into some rain and possibly some storms today around the Southeast, but it will be nothing compared to tomorrow. Overall, it would be much safer to try and get your driving done today. But, I know that’s not possible in many instances. So, if you will be doing your driving tomorrow, please make sure you are staying on top of the weather. We’ll be updating here and on Twitter all day, but we can’t cover the whole area that’s going to see some crazy weather tomorrow. David posted this yesterday, but here it is again: Leave early and arrive early, before the weather arrives. Those of you planning to drive south into Alabama or Mississippi, or west toward Memphis, on Wednesday should reconsider travel plans in consultation with weather sources at your destination. For North Alabama,
@simpsonwhnt, Central Alabama, @spann, for Memphis, @memphisweather1, and for Jackson MS, @NWSJacksonMS. There are also several other reliable social media sources of weather information.
Note: SPC graphics are up-to-date as of 11:40 AM.
Christmas Eve & Christmas Day
Rain and even some storms will hang around through the end of the week, but the severe threat will be gone.
This website supplements @NashSevereWx on Twitter, which you can find here.
Categories: Forecast Blogs