Risk for Severe Weather Today and Tonight (Friday, July 20th)

NOTE: This blog post is pertaining to the severe weather risk for the day and night of FRIDAY, JULY 20th, 2018.

Get ready, West Tennessee! We don't often have severe weather in the middle of July, but the current weather set-up warrants advanced notice of a threat of severe thunderstorms that could produce large hail, damaging winds, and isolated tornadoes.

Currently, as of creating this blog post at 11 a.m. this Friday morning, thunderstorms moving through eastern Arkansas have created a layer of cloud cover over most of West Tennessee. This is a good thing! Typically, a layer of cloud cover in the morning, can inhibit daytime heating and limit the threat for severe weather. It won't remove the threat completely but it certainly could keep thunderstorms from becoming as strong as they would have with perfectly clear skies.

Here's a look at satellite from this morning and the radar showing where showers and clouds were just after 10:30 a.m. with the activity moving southeast.

This afternoon and evening is when our threat for severe weather will increase, and the risk will rise quickly. All of West Tennessee (as of 11 a.m.) is at least under an enhanced risk but northwest Tennessee near the Tennessee River is under a moderate risk for severe weather. That's a level 3 or 4 out of 5. Again, something very unusual for July.

Models that we use to simulate what radar may look like throughout the day have not been doing a good job with the thunderstorms that moved through Arkansas this morning, so we're going to have to talk about timing carefully.

All models have shown showers and thunderstorms moving through West Tennessee after sunset tonight, but a few of the more recent simulations show that thunderstorms could start developing and become severe near Paris, Martin, Huntingdon, and Camden as early as 2 o'clock this afternoon.

Here's a look at what those latest models show in terms of coverage of showers and thunderstorms through 11 o'clock tonight.

The biggest takeaway you should get from this animated picture, is not "when will it hit my house" but notice that not everyone in West Tennessee will get rain today/tonight much less severe weather. The timing and location of the incoming thunderstorms is still extremely uncertain.

All forms of severe weather are possible, including large hail and damaging winds as a primary concern especially in the area under a moderate risk for severe weather. However, an isolated tornado is also possible anywhere in West Tennessee.

If you're going to be out of the house and away from the TV today, just make sure you have a way to get weather watches and warnings on your phone! That could be as simple as using your Twitter account to get "Mobile Notifications" from any one of the meteorologists at WBBJ (@WBBJ7Weather, @WBBJ7TomMeiners, @WBBJ7Moe, @WBBJ7Corallys, or @WBBJ7Brian). Or you could use wbbjtv.com/live to watch our newscasts live at 11:30a, 12, 5, 5:30, 6, 6:30, and 10 for updates.

SUMMARY

• Latest data has some thunderstorms developing in West Tennessee as early as 2pm
• Severe weather is possible today but the timing and location of severe thunderstorms in West Tennessee is still uncertain
• Not everyone in West Tennessee will get rain and fewer will get severe weather
• Thunderstorms will be likeliest to occur this afternoon and evening through sunset
• Large hail and damaging winds are the main threats but an isolated tornado cannot be ruled out

Risk for Severe Weather and Flash Flooding Tonight and Tomorrow (Saturday, April 14th)

NOTE: This blog post is pertaining to the severe weather risk for the night of FRIDAY, APRIL 13th, 2018 and the day of SATURDAY, APRIL 14th, 2018.

Another round of showers and thunderstorms is threatening to bring heavy rain and severe weather to West Tennessee tonight and tomorrow. Here are a few things to think about when considering this forecast...

• there's a wide window of opportunity for a strong thunderstorm or flash flooding in West Tennessee
• we need to keep a method of receiving watches and warnings on hand throughout that time period
• another shot of cold air will come behind this front

Let's begin by talking about the timeframe. There may end up being multiple round of showers and thunderstorms for parts of West Tennessee tonight and tomorrow. This graphic below, will simply show you when the first round will arrive late tonight into early Saturday morning.

After the first round, there will be a chance for more storms to occur in West Tennessee later in the morning and afternoon on Saturday. Now, about the threat for severe weather...

The risk shown here exists from tonight through 7 a.m. Saturday. Most of our viewing area is under a slight risk (2 out of 5) for severe weather which means that scattered severe storms are possible. They are more likely to be short-lived but intense. Portions of southwest Tennessee including Memphis are under an enhanced risk (3 out of 5) for severe weather which means numerous severe storms are possible there and they may be more persistent and/or widespread. Finally, portions of West Tennessee near the Tennessee River such as Paris, Camden, Hollow Rock, Bruceton, Parsons, Decaturville, and Savannah are under a marginal risk (1 out of 5) where isolated severe thunderstorms are possible but they're more limited in their intensity.

As for tomorrow, this graphic shows a risk for severe weather continuing into Saturday and this graphic forecasts from 7 a.m. Saturday through Saturday evening.

...most of West Tennessee is in the marginal risk (1 out of 5) zone but portions of southwest Tennessee near the Tennessee River including Parsons, Decaturville, Chesterfield, Sardis, Reagan, Jacks Creek, Henderson, Middleton, Selmer, Bethel Springs, Savannah, and Counce are under a slight risk (2 out of 5) for severe weather.

Tonight into Saturday morning, damaging winds are the main threat. An isolated tornado cannot be ruled out along the squall line as it moves in but the threat for a spin up is more likely closer to the Mississippi River. During the day on Saturday, all forms of severe weather are possible (damaging winds, large hail, and an isolated tornado) but the main threat is still for damaging winds.

Here's an image showing what radar could look like Saturday afternoon at 4pm. Showers and thunderstorms will be moving from southwest to northeast. Those thunderstorms near the Tennessee River could be strong or severe and we'll be watching that area very closely tomorrow.

In terms of rainfall, a Flash Flood Watch is still in effect for most of West Tennessee tomorrow.

The vast majority of our viewing area is looking at a potential for 2-4" of rain to fall between tonight and Saturday night. A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation! Excessive rainfall, up to 2 inches an hour will be possible. Urban areas, low lands adjacent to rivers and streams, and low water crossings will be the most vulnerable to the heavy downpours. You should monitor our future forecasts and be prepared to take action should flash flood warnings be issued.

SUMMARY

• Strong thunderstorms will move across West Tennessee late tonight into Saturday morning
• Damaging winds are the main threat tonight and tomorrow but isolated tornadoes are possible
• Multiple rounds of heavy rain may occur in portions of West Tennessee, but especially in areas close to the Tennessee River
• A slight risk for severe weather is forecast for southwest Tennessee near the Tennessee River tomorrow morning and afternoon
• Flash flooding could occur in West Tennessee with 2-4" of rain falling from this event

Make sure keep a method of receiving watches and warnings on hand throughout tonight and tomorrow, and watch WBBJ 7 Eyewitness News for the latest forecast!

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.