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3 Days of Severe Storms Possible; Monday Especially Concerning

NOTE: If you’re looking for current conditions/radar, scroll all the way down.

Round 1 – Sunday Afternoon 

Sunday, a warm front will move north into Middle Tennessee, bringing humid air with it. Humid air is an important ingredient for severe weather. It provides storm fuel.

The Hi-Res NAM thinks rain and a few storms will begin by mid-afternoon tomorrow:

Strong storms are possible, but severe weather is not expected with this initial round of rain (assuming it even happens).

If you have something going on outside Sunday afternoon, check in Sunday morning for an update on the HRRR short-range model. It usually has a very good handle on when/where storms will develop.

Round 2 – Late Sunday Night & Early Monday Morning

By 9 PM Sunday night, supercell thunderstorms should be exploding in Arkansas. Again, from the Hi-Res NAM:

These storms are expected to march into West, then Middle, Tennessee, early Monday morning. By 4 AM Monday morning, they’ll congeal into a cluster, and should be moving across the Tennessee River, toward I-65 during the morning commute:

The main concern with Round 2 will be west of I-65. These storms will be capable of damaging straight line winds, large hail, and heavy downpours.

Round 3 – Late Monday Afternoon & Evening

This the main concern. There will be much better information on this Sunday, but for now, our best thinking is as follows:

Writing today about this round of storms, our NWS said (in blue):

Conditions will be favorable for a major outbreak of severe weather across all of Middle Tennessee, including:

  • Tornadoes
  • Damaging wind gusts
  • Large hail, and
  • Flash flooding.

Sticking with the Hi-Res NAM (which isn’t infallible, by the way), you can see these storms explode Monday at 1 PM:

4 PM:

7 PM:

Notice the development and maturity of the storms. You shouldn’t put too much stock in the specific timing depicted above. These storms will increase in coverage Monday night, impacting in various ways everyone (and if not, almost everyone) in Middle Tennessee Monday night.

The ferocity of these “Round 3” storms will be influenced by several factors about which we lack confidence. Among those factors — likely the most important factor of them all — is the amount of sunshine we see after Round 2 departs, but before Round 3 begins, late Monday morning and early Monday afternoon.

However, even if the sun isn’t shining, a significant threat of severe weather remains for everyone and anyone in Middle Tennessee. All the weather models agree — conditions are extremely favorable for severe weather. This is a potentially serious situation for Middle Tennessee.

Round 4 – Tuesday

The same weather system which brought us Monday’s storm system may bring more severe weather. Our NWS thinks the greatest threat will be in southern Middle Tennessee and the plateau, but everyone in Middle Tennessee could be impacted. The same modes of severe weather (tornadoes, damaging winds, large hail) threatening us Monday will be possible Tuesday. More on this Sunday and Monday.

Should You Freak Out?

Panic helps no one, and there is, frankly, no current reason for panic. There isn’t going to be a 600 mile wide tornado wiping out all of Middle Tennessee. So, if you’re feeling apprehensive for yourself and those around you, channel that energy into preparing for severe weather.

If your question is: “Will a tornado hit my house?,” the answer is that’s an unanswerable question. The odds are that you won’t be impacted, but no one really knows. I’m talking to all 24,500 of you who follow us on Twitter and anyone else who is listening, and I’m concerned many — and perhaps a good many — of you may be impacted. And I want what you want, which is your safety.

So, what should you do? This isn’t a comprehensive list, but I do want to highlight a few things.

For starters, be sure to have multiple reliable sources to receive Watch and Warning information. This should include an app, a NOAA weather radio, “regular” radio, and/or, of course, local TV (2, 4, 5, and/or 17).

I think your well being is worth heeding NWS Warnings. This means you taking cover in a lowest level, interior room of your house (not a trailer and not a car), with your shoes on, ID in your pocket, charged phone, and helmets for everyone. If you’re in a Tornado Warning polygon (more on this below), do not go to the front door and try to see it — it’s very likely going to be wrapped in rain. You. Will. Not. See. It.

Remember, a Watch means conditions are favorable for the development of a tornado. You should “watch” and otherwise monitor your sources of severe weather information, already prepared to take action if a warning is issued.

A Warning means a tornado is occurring or imminent. It could mean a tornado is detected on radar (but no one has reported it … yet). It could mean one has been spotted or has otherwise been confirmed on the ground. Act anyway.

A Warning always comes with a polygon. Those inside the polygon are in the warned area and should immediately take shelter. Those outside the polygon aren’t warned, but if you’re close to it, take cover anyway.

Example:

You can help the NWS and your community by tweeting your report of occurring severe weather (funnel cloud, wall cloud, tornado, trees down/structure damage, hail the size of a quarter, flash flooding) to NWS-Nashville by including the hashtag #tSpotter. Either geotag your location, or let us know where you are and when you saw it. The NWS will see your report, and it could assist the NWS in issuing a warning that saves someone’s life.

Note: WARNINGS WILL NOT BE POSTED TO THIS WEBSITE.

Finally, don’t forget about the Flash Flooding potential. Do not drive over water-covered roads. It’s cheezy, but true: “Turn Around, Don’t Drown.”

We’ll be up with another post in the morning.

Current Official Hourly Observation (taken at :53 on the hour)

Current Radar Loops

Local radar loop includes live severe weather warning

Temp & Rain Probabilities Next 36 Hours (auto-updating)

This website supplements @NashSevereWx on Twitter.

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