All eyes are looking at forecast models this afternoon, and will continue to monitor them through the next 24-36 hours as a powerful storm system looks like it will setup to our West tomorrow afternoon. When it's this warm in January, you know something is up. Read below to see the latest thinking.
SYNOPSIS: The Storm Prediction Center has upgraded the severe risk to "Moderate" for parts of Arkansas, Louisiana, and the Mississippi Delta. We are under a "Slight Risk" for now, but this could change. This storm system has both the Thermodynamic (energy) and Dynamic (wind flow) parameters in place for a pretty significant severe event to unfold over the Southern and Southeastern US tomorrow afternoon through Wednesday afternoon. There will be plenty of instability with CAPE (Convective Available Potential Energy) ranging between 500-1000 J/kg. Our dewpoints will be above 60 degrees (that's a commonly used threshold used when forecasting severe weather), and the atmosphere will be quite moist with Precipitable Water values close to 2 inches. (Precipitable water is how much water would fall to the earth if you condensed it all out of an imaginary column through the atmosphere (kind of weird, I know)). The upper level winds will also be howling, with 80 mph winds just above the surface, and 120 mph winds in the middle of the atmosphere. It won't take much to mix those kinds of winds down to the surface. So, without wanting to scare anyone, this is not your average, run of the mill low end risk event. It's nothing to lose sleep over, but take precautions, and we'll all get through it together just fine!
WHAT TO EXPECT: Tomorrow will be a breezy day leading up to the arrival of the storms. We'll see winds sustained in the 15-20 mph range, with gusts as high as 30 mph. The main risk from this system will be damaging straight line winds as a squall line develops back to our West. Remember that trees, power lines, and your house don't know the difference between a tornado and straight line winds, so if you go under a Severe Thunderstorm Warning, take it just as seriously as you would a Tornado Warning. That being said, the winds at the surface will be in a different direction than the winds aloft, so there will be the chance for storms embedded in the squall line to rotate, as well as storms that form ahead of the line, so there is a tornado risk. Be ready for heavy rain, 70 mph+ wind gusts, and a few tornadoes.
WHEN?: The storms should approach the western part of Mississippi before Midnight tomorrow night, but we should start seeing action around 2:00AM and lasting through a good portion of Wednesday morning before it clears our Western Alabama counties by about 6:00 AM or so. Timing is still the biggest question right now. Models have come into better agreement regarding timing over the past few runs, but there is still about a 3-6 hour window of discrepancy, so right now that is our best timing forecast, but look for it to change as we get more information.
WHAT DO I NEED TO DO?: The thing you don't need to do is worry or be scared. We've dealt with things like this before, and situations that have been way worse. The absolute number one thing you can do is to make sure you have a way of getting warnings. This event will take place during a time when most of us are asleep, so make sure you have your NOAA weather radio on, and have extra batteries incase you lose power (which is a real possibility). Other options include smartphone apps that can pinpoint where your phone is using GPS and bring you the new(ish) polygon based warnings. Brian and I of course will be here watching, so as soon as you get a warning, make sure to tune in, and we will be on as long as we need to be to track the storms down to your neighborhood.
ONE FINAL REMINDER: The absolute last thing I want to do is make people worry. Like I said, as long as you have a way to get warnings as soon as they're issued, we'll all be fine. Going ahead and reviewing your tornado safety plan for where you'll be early Wednesday morning will also help. Hopefully we won't have to put those plans into action, but it's best to be prepared.
Brian and I will have updates on all Newscenter 11 Newscasts, as well as frequent updates to the web whenever our thinking for this event changes. They will be posted to wtok.com, with a link to the forecast discussion on our Facebook page.
Remember that you can track the storms using Southern Pine Electric Power Interactive Radar on wtok.com/weather