There seems to be this trend so far this year of severe weather during the weekend. In case you’re unaware, the weekend may be the most inconvenient time to have severe weather. I know you all have plans and get bummed when they’re canceled. Do not blame this on me as I am the creator of all things weather I just predict it. The phrase “don’t shoot the messenger” seems fitting. That being said the topic of today’s blog may be obvious. Today’s blog will be all things severe weather for the weekend.
Slight ridging will develop today to our west as an upper level trough deepens and develops even further west. Through the rest of the evening and the overnight, that trough will eventually push its way east and become tilted. The trough will become tilted because the associated area of low pressure will take a northeast path eventually finding itself over the Great Lakes by the end of the day Saturday. As the low lifts NE the associated warm front will gradually lift north as well. This will allow temperatures to warm on Saturday into the mid and even upper 60s.
The Storm Prediction Center (SPC) has gone ahead and placed parts of the Tennessee Valley under a SLIGHT risk for severe weather on Saturday. Everyone east of I-65 is under just a MARGINAL risk for severe weather. The slight risk means scattered severe weather is possible, and the marginal risk means that an isolated severe storm is possible, but the chance is very small.
With that in mind, it is important to note that the chance for severe weather in the Tennessee Valley is very SMALL. I want to make this point very clear since I understand there is a certain level of discomfort following the Lee County tornado. I am not here to tug at emotions or take advantage of vulnerability. I am simply here to educate and inform. What you do with this information is 100% up to you.
The ridge may allow some of the clouds to break early Saturday morning, but I don’t think that will be enough to allow plentiful sunshine to get through which would then destabilize our environment. Looking at the forecasted CAPE I notice less than 500j/kg/k through the afternoon and evening tomorrow. We need CAPE to be at least 500j/kg/k before we get concerned. We could see some elevated wind shear, but even that doesn’t look like enough to get things going. I see the GFS is forecasting dewpoints in the lower 60s meaning the moisture is certainly there.
As far as timing is concerned, futurecast tries to bring this main line of thunderstorm activity through beginning around the lunch hour and continuing through the early part of the evening. By 3:00 PM Saturday, futurecast has the main line crossing the I-65 corridor. There is something in the video I want you to notice. Behind the line you can see some more activity popping up in the evening. I don’t see much of any reason those showers would become severe as the atmosphere should be well worked over once the initial line comes through.
What are the big threats? Damaging winds and flooding top the list. Large hail and tornadoes round out the bottom. While the chance of a tornado is there the chance is VERY small.
Still as with any opportunity for severe weather no matter how big or small I’ll go ahead and remind you to always know where your safe place is.
To finish on a happy note, I’ll remind you that DST begins this weekend. We lose an hour of sleep, but gain more time to our day.