Thankfully, for us, the best severe weather ingredients will miss us just to the north. BUT, we will still have enough lift, instability, and wind shear in place to get severe storms.
The map about is the severe weather outlook from the Storm Prediction Center. They issued the first "high risk" of the year (this is pretty early for a high risk by the way) for parts of Kentucky and Tennessee. That area is surrounding by a fairly large "moderate risk", which includes the northeast chunk of Mississippi. And a "slight risk" encompasses the rest of Mississippi, including the WLBT weather coverage area. You can think of these risk areas in terms of where the highest concentration of storm reports will be. High risk being widespread, moderate risk being scattered, and slight risk being isolated.
We'll spend much of the daytime hours today just making the atmosphere more unstable. Those gusty winds you feel today are coming off the Gulf of Mexico, rapidly sending low level moisture into our area and points to our north. The south wind is also pumping in some very warm air. I expect highs well into the 80s with lots of record highs being tied or broken.
As often is the case, we will be watching for what may be two areas for storms to form. The eastern part of the area may get both rounds. First off, we have to watch for any individual cells that fire from after 4PM-9PM. These cells will have the highest potential to produce severe weather, especially in the form of tornadoes The best areas to see this are east of I-55 and north of I-20, but we could see them form further south and west, too.
By mid to late evening, the concern will then shift to the cold front. I expect to see a squall line evolve just ahead of the front late this evening and move through overnight. The main risk from the line will be from strong straight-line winds, but quick spin-up tornadoes are also possible.
The map above plots what we call the EHI or the Energy Helicity Index. The EHI is determined from a combination of instability (CAPE) and shear/inflow (helicity). If you're a weather nerd, you can read the geeky stuff about this here. But, for everyone else, the EHI is just a good way to see where tornadoes may and how strong they could be. The higher the value, the more likely and stronger the tornadoes have the potential to be. You'll see on the map, the oranges and reds our to our north around mid-afternoon. That's why the SPC issued that "high risk" for that area. Even though our EHI values are lower, they are still high enough to support tornado formation.
That's all for now. Today is Read Across America Day. I started my day at 7:30am, reading at Madison Avenue Lower Elementary School in Madison. I'm getting ready to head to Poindexter Elementary in Jackson. I'm reading "One Fish, Two Fish, Red Fish, Blue Fish" by Dr. Seuss.
Keep your weather on and programmed. We'll likely see a Tornado Watch issued later today. Remember, a WATCH means conditions are favorable. A WARNING means it is happening now and this is when you need to take cover. Recall the DUCK safety rules. Downstairs, Under Something, Center of Building, Keep Away from Windows. Should a tornado be headed for your area, you can wear a helmet to protect your head, along with goggles, a heavy coat and gloves.
You can follow me on Twitter and Facebook for more updates throughout the day.
- Eric
