Forecast Blogs

Biggest Threat Shifting Bit Further East, But Don’t Ignore It! ETA 2-6 PM.

Severe weather is possible today, although the risk seems to be shifting further east.

A higher risk to the east doesn’t mean you should ignore the risk here. Risk area may be wrong. Storms don’t care where we draw these lines.

ETA 2 PM to 6 PM (Rush Hour?)

These times are estimates and will likely change as we move through the day.

I think we are on the early side of this ETA, in the 2-4 PM range.

There is a lot of uncertainty with the timing due to the fact that we do not know when/where these storms will develop. They could very easily develop right over us before racing eastward.

This thinking is displayed by the latest run of the HRRR, shown below.

Notice how there really isn’t anything, and then around the 3 PM-ish mark, storms fire right over our area. Note that this is just one model. The NAM3 model also shows storms developing right on top of us around mid-afternoon.

You may ask “well there isn’t a cloud in the sky right now and I don’t see anything on the current radar.” You probably won’t until they are right over us. These storms are expected to develop quickly and leave quickly; it’s also possible the storms form east of us and run away from us, and we get nothing.

Even if we do get storms, they won’t form a line. They’ll form individual cells, and turn into supercells. Some of us may not even see any rain at all.


David did a Persicope this morning based on then-current Storm Prediction Center probabilities.

SPC shifted the risk just a bit further east — and away from us — since then. The 11:29 AM outlook from SPC now has us:

Inside a 5% probability of a tornado within 25 miles of a point (but very close to the 10% probability):

30% probability of large hail within 25 miles of a point:

15% Probability of damaging winds within 25 miles of a point:

We talked yesterday about the uncertainty of morning storms to our south “cutting off” the storm food flow. While there are storms to our south, they do not appear (so far) to be limiting any of our storm food, which is not the best news. However, they still have a long way to go — we will be watching the data this morning to see if the dewpoint rises into the 60°s. If it does, the storm food predicted to be in place by the HRRR model will be correct, and the storms will have plenty of power to tap.

Uncertainties Remain!
  • There will be storms somewhere in Middle and/or Eastern Tennessee today.
  • We do not know if the storms will form right on top of us or to our west before racing eastward. The trend is an eastern development, which is great for us, and bad for those to our east.
    • If storms form right on top of us, they could possibly be not as strong as they would be if they formed to our west before moving into our area.
  • All three of our severe weather threats (large hail, damaging wind, tornado) are possible. Large hail and damaging winds are the greatest threat, but do not rule out a tornado.
  • Review severe weather plans if you haven’t already. Consult multiple weather outlets throughout the day. Have your weather radios & smartphones handy, these storms will likely develop rapidly, giving us only a short amount of time to prepare.
  • If we get a tornado warning, please shelter in place. Do not rush to pick up your kids if it will risk you (or them) getting caught outside in it. Schools are generally safer places than vehicles.

There are still plenty of uncertainties that will likely not be answered until later today. This forecast will likely change as we move through the morning. Follow us on Twitter and tune in to local TV meteorologists for up-to-date information.

Rest of the Week Into the Weekend

Categories: Forecast Blogs