Risk for Severe Weather Tonight (4/3/2018)

NOTE: This blog post is pertaining to the severe weather risk for the evening of TUESDAY, APRIL 3rd, 2018.

April is the second most common month for tornadoes in West Tennessee. In fact, it was 12 years ago yesterday, that parts of Dyer, Gibson, Weakley, and Carroll counties had to deal with one of (if not the) longest tracked tornado on record for West Tennessee moving from northeastern Arkansas to southeast Missouri and eventually northwest Tennessee. Today, the main concern is the threat for damaging winds but the threat for tornadoes is becoming a bit more concerning for northwest Tennessee.

Here's a look at the potential threats for tonight...

...and a look at the timeline for those threats...

...most of the bad weather won't be coming until sunset or later. The storms will be moving through quickly too, so by midnight not only is the risk for severe weather over but the rain should be gone for the most part too.

Right now, we're seeing abundant sunshine poke through the clouds and that's leading to a more unstable atmosphere already. We look for 1,000 units of energy in the lower atmosphere for severe storms this time of year and we're already there at 10 a.m. this morning!

A Wind Advisory also just went into effect with a potential for winds to gust between 30 and 40 miles per hour even before the storms arrive this evening.

However, the fact is, not everyone in West Tennessee will get severe weather tonight. We may all get rain, but depending on how the incoming squall line unfolds, we may see some spots get just rain, and other areas get strong thunderstorms. This animated image shows what radar could look like this evening. A big concern is if we get discrete thunderstorms ahead of the main line to form tornadoes before the cold front moves in. That appears to be getting more likely, so the late afternoon hours will be watched closely too.

One parameter we look at for our threat for tornadoes is the "Significant Tornado Parameter". It's on a scale from 0-9, and some of the data has shown that number increasing every time the data gets refreshed. It's now at a 4 in northwest Tennessee at 7pm tonight.

That appears to be where tornadoes will be likeliest before the threat transitions to mostly a damaging wind and large hail threat for areas near the Tennessee River and south of I-40.

SUMMARY

• A Wind Advisory is in effect today with winds gusting between 30 and 40 mph even before rain arrives
• THREAT TIMELINE - 5PM TO 10PM
• Not everyone will see severe weather
• The strongest storms could produce primarily damaging winds and large hail as well as a few tornadoes 
• Northwest Tennessee is where tornadoes are likeliest to occur this evening if any form at all

Make sure you have multiple ways to receive weather information whether that be using your television to watch us on WBBJ or with a NOAA weather radio, or your smart phone. Keep that smartphone charged in case the power goes out! We'll do our best to stream live coverage of the storms on Facebook should we need to.

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

Winter Storm Review

NOTE: This blog post is pertaining to the winter weather that occurred on Friday, January 12th, 2018.

Some locations accumulated a little more snow than expected today but most of the area received what we expected. Jackson, Lexington, Medina, and Cedar Grove were some of the areas that got 4-6" of snow when 3" was expected at most, but the atmosphere had other plans. Because we got a significant amount of sleet this morning, that made it easier for the snow to start sticking immediately upon falling. Our other factor was the snowfall rates which were high enough to cause totals to increase very rapidly.



Ultimately, this winter storm is finally starting to come to an end with snow and ice totals in northwest Tennessee as high as 8" and as little as just a trace in southwest Tennessee. A few snow showers just recently tapered off along the Tennessee River. We'll start the melting process tomorrow but this snow and ice may stick around some areas for several days.

TONIGHT
Black ice is the main concern for us overnight and it's expected to be a problem for virtually all of West Tennessee. Temperatures will get well into the teens at the coldest point of the night and wind chills will be in the single digits early Saturday with winds still out of the north at 10 to 20 miles per hour.
Skies will become clearer tomorrow with sunshine getting the melting process going but I believe we'll have black ice on Sunday morning too. Shaded areas will hardly see any melting at all because high temperatures will only be in the upper 20s and lower 30s. Be very careful if you have to drive in the area tomorrow!

Stay with WBBJ 7 Eyewitness News for the latest forecast and keep up with Storm Team Weather online too for more updates.