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Tomorrow’s Damaging Wind & Tornado Threat

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

Temps Next 24 Hours (auto-updating)

Current Radar Loop

TonightWarm, Chance of a Shower or Thunderstorm – Low in the low 50s

A shower or thunderstorm may drive by late tonight from the southwest; otherwise, we’ll be mild and partly cloudy.

ThursdaySevere Weather – AM Low 53, PM High 75

First, let’s clear up some misinformation floating around before it becomes “a thing.” Ari tweets it well (and yes, I see the irony of sharing when it says DON’T SHARE):

That’s nonsense. As for the legit forecast…

Before the Storms, A Mighty Wind.

A Wind Advisory is in effect from 9 AM until 9 PM. South winds will be howling, sustained at 20-30 mph, with gusts between 40 and 45 mph. Be sure to shelter or otherwise secure your 88 year old, 88 pound aunt, because these winds will knock her down, God Bless Her.

These south winds will pump unseasonably warm and wet air into Middle Tennessee.

From the west, an “It’s Still February,” dry air toting cold front is coming. This will trigger strong and severe storms across Middle Tennessee.

What’s The Threat from the Storms?

Damaging Wind – this is the most likely form of severe weather. Severe winds (58+ mph) are likely to be found inside the main squall line.

Tornadoes – less likely than the damaging wind threat. The SPC says “a few tornadoes” are possible. If they happen, they’ll be inside the squall line (usually on the leading edge). These tornadoes typically are short lived and relatively weak; however, strong and deadly tornadoes can be found inside these storm lines. For example, we had an EF-2 tornado in a similar squall line on January 30, 2013.

Locally Heavy Rainfall. Flooding is not a concern, but we could see ponding of water in low-lying areas.

How Can I Quantify the Threat?

Note the SPC Outlook below, and especially the “hatched” (shaded area):

We are on the fringe of the hatched/shaded area, which means there is a 10% or greater probability of

  • tornadoes rated EF2 or greater, and/or
  • thunderstorm wind gusts of hurricane force or higher (74+ mph)

happening between 0 and 25 miles of those inside that hatched/shaded area.

The regular red-shaded area (which includes both Davidson & Williamson Counties) means there is a 30% probability of a severe wind gust (58+ mph) or a tornado happening between 0 and 25 miles of you.

Here’s another way to view the threat levels:

Estimated Time of Arrival (ETA)

Between 5 PM and 8 PM.

There is general agreement on the timing range, but please check back tomorrow. These estimates are not always spot-on 30 hours before the event. However, we feel pretty good about this ETA range. Even the NAM, which yesterday had the main line arriving around 3 PM, now thinks it’ll be here after 6 PM:

Today just happens to be the day set aside for Tornado awareness during Severe Weather Awareness Week. Now is a good time to review some of the safey rules, below. If you’re new to Middle Tennessee or tornado country in general, or if you are one of those people who have not memorized all tornado safety rules, read this from @WilsonSevereWx.

NWS YouTube summary:

We cover only Davidson and Williamson Counties. For other counties, follow @RuthSevereWx, @WilsonSevereWx, @RobCoSevereWx, @SumnerSevereWx, and/or @MaconSevereWx.

No Warnings are ever posted to this website. We relay warnings, and a ton of other info, on Twitter @NashSevereWx. This website only serves to supplement the content put on Twitter. Please consult multiple reliable weather sources (in case we are eaten by a sharknado) today and tomorrow, and heed all warnings.

I don’t think you need to freak out, but don’t ignore this, either. Just have a plan in case a warning is issued.

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