Severe Weather Threat Through Tonight

Posted on by Caroline MacDonald

Downgraded (but still some) Risk of Severe Weather Later

Overnight, the Storm Prediction Center removed us from the “Moderate Risk” (4 of 5) and fell back to an “Enhanced Risk” (3 out of 5), and now, this morning at 8 AM, down to “Slight Risk” (2 out of 5)  for damaging winds, large hail, and tornadoes today.

Still More Showers and Thunderstorms to Come

Why the Reduction in Risk?

The removal from “moderate” to “slight” likely has to do with SPC thinking the wind risk should be 15% instead of 45%.

Why?

Remember yesterday, we were talking about whether the sun would come out, and how that will impact this event. More sun = more storm. More clouds = weaker storms.

So far today, we have had a lot of clouds (which is good news for us). However, there is beginning to be a break in the clouds to our west (no break for us yet).

If (there is lots of uncertainty with this) clouds stay overhead and don’t break, it will limit the severity of the storms, because they won’t have that much storm fuel to feed on as they approach I-65. Dewpoints have remained under 60° so far today, which is another indication of a failure to launch the worst risk of this event.

One model, the NAM3, predicts a robust, intense, and tornado-capable line of storms. Other models show less robust storms.

So, this is a wait and see event. There is no consensus. Because of the uncertainty, our removal from 4 of 5 — usually reserved for more certain events — was warranted.

In terms of rainfall, when it comes, it will be extremely heavy and fall at an extremely fast rate. Localized flooding could become an issue quickly.

The graphic below shows the Weather Prediction Center’s (different from the Storm Prediction Center) concern with the amount of rainfall we could see today.

In terms of damaging winds, hail, and tornadoes, below are the Storm Prediction Center probabilities:

15% Probability of Damaging Winds Within 25 Miles of a Given Point

15% Probability of Large Hail Within 25 Miles of a Given Point

2% Probability of a Tornado Within 25 Miles of a Given Point

Uncertainties remain. This is an evolving forecast that WILL change throughout the day. So far, it’s been changing for the better.

Embrace the uncertainty and stay weather-aware throughout the day. We will likely see some sort of watch (whether it be a Severe Thunderstorm or Tornado Watch) before the end of the day. NOW is the time to review your severe weather plans and to prepare.

Prepare:

Review your severe weather safety plans.

  • If you live in a mobile home, locate a sturdier structure well in advance of these storms. Some local churches and other public entities are opening their doors tomorrow for shelter during the potential severe weather.
  • Predators game…have tickets to the game? With the game starting around the time storms may hit, do not get caught in your car when they arrive. Also, if storms are ongoing at the time of your departure from the Arena, wait it out and let them pass.

Have multiple outlets to receive weather information from tomorrow, including @NashSevereWx on Twitter.

New to severe weather? Click for more information.

Rest of the Week

Into tomorrow morning, we could have a few early morning showers. Any, if at all, showers we do see should be gone by the lunch hour. For the rest of the day, expecting for mostly cloudy skies.

This weekend looks phenomenal with warm temperatures and sunny skies for both Saturday and Sunday.

By Sunday night, we will begin to see our next active weather pattern. More on this tomorrow.

5-Day Allergy Forecast From Pollen.com