Risk for Severe Weather Tomorrow (3/19/2018)

NOTE: This blog post is pertaining to the sever weather risk for MONDAY, MARCH 19th, 2018.

Spring is the most common season for severe weather to occur in West Tennessee. March, April, and May are when severe thunderstorms are most frequent and this probably comes as no surprise since we had multiple tornadoes, damaging wind, and large hail storms come through around this time last year.

Tomorrow will bring an opportunity for severe weather to return.

All of West Tennessee is under a risk for severe weather, but the threat becomes more serious the closer to the Tennessee River you are. Our western counties near the Mississippi River are under a marginal risk (1 out of 5). Most of our viewing area is under a slight risk (2 out of 5) and this can be seen as the area colored in yellow. The enhanced risk (3 out of 5) is for parts of Benton, eastern Henderson, Decatur, and most of Hardin counties which includes Camden, Holladay, Darden, Parsons, Decaturville, Scotts Hill, Sardis, Bath Springs, Saltillo, Savannah, Olivehill, and Counce.

Now before we dive into threats, lets talk about timing and when you should be weather-aware tomorrow. 

9am to 5pm

I know. That's a large window of time, and severe weather won't be occurring during this entire time, but for the 21-county area of West Tennessee, those are the hours your Storm Team will be most vigilant. It's the duration of time that the "door" will be open for storms to move in. I've seen on Twitter that some schools in Alabama are already going to be dismissing early tomorrow. I hope that's not the case here! The timing in the storm threat just doesn't make putting students on buses a smart idea.

Regarding the potential threats, here's what the situation looks like. We forecast multiple ingredients when it comes to deciding what threats are likeliest. Ultimately, we need three important things - moisture, energy, and a lifting mechanism. We have a strong lifting mechanism in an area of low pressure, and a decent amount of moisture, but the amount of energy remains a little uncertain. Temperatures will be warming up to the upper 60s and lower 70s, but the more likely potential for any energy to create severe weather will be farther to our south and east across northern Mississippi, northern Alabama, and Middle Tennessee.

Another important ingredient for severe weather includes wind shear which can be described as a change in speed of the wind and direction of the wind with height. There will be plenty of that, but without a trigger or enough energy this factor becomes less important.

Given the parameters, large hail seems to be the most likely candidate for a severe thunderstorm on Monday. Showers and thunderstorms will be starting out in individual cells, and when a thunderstorm is its early stages, large hail is a common threat. Damaging winds are possible too but fall second to hail in this case. An isolated tornado will be possible as well, but especially south of I-40 in the area highlighted in yellow below...



...and if a tornado is going to develop, it's more likely in the afternoon than in the morning.


Here's the good news!

The area of low pressure responsible for this threat for severe weather looks as though it's taking a more southward track. This means, our energy levels could be limited, preventing thunderstorms in West Tennessee from becoming too strong. 



The new data coming in certainly seems to be trending in this direction. Let's hope that that's how things turn out! Meteorologist Corallys Ortiz will have an update on the forecast on WBBJ 7 Eyewitness News at 10! 


SUMMARY

• BE WEATHER AWARE TOMORROW FROM THE LATER HOURS OF THE MORNING THROUGH THE AFTERNOON
• CHECK WITH US FOR ANY CHANGES TO SCHOOL SCHEDULES
• IF A THUNDERSTORM BECOMES SEVERE TOMORROW, THE MAIN THREAT IS LARGE HAIL WITH A SECONDARY CONCERN FOR DAMAGING WINDS AND AN ISOLATED TORNADO
• BEST CHANCE FOR A TORNADO IS IN SOUTHWEST TENNESSEE DURING THE AFTERNOON
• THE TREND IS FOR THE SEVERE WEATHER RISK TO BE LOWER
• UPDATE ON WBBJ 7 EYEWITNESS NEWS AT 10