Scattered Thunderstorms This Afternoon and Evening

NOTE: This blog post is pertaining to a chance for severe weather that is forecast 

for today, Friday, April 28th, 2017.

Showers have already begun in northwest Tennessee but as of this morning, West Tennessee is in an area that could see severe thunderstorms develop later on today. If you saw any of my weathercasts or posts yesterday, you know that there was still some uncertainty with this forecast. Today, the area that could see these thunderstorms is still uncertain but there are a few things we've learned from the weather data this morning.

West Tennessee is split between having no risk for severe weather at all and an enhanced risk (3 out of 5) which is largely placed north of I-40. If thunderstorms develop there today, that is where they could become severe.

To help convey the uncertainty with today's forecast, let me show you some of the latest weather data.

This computer model shows heavy showers and thunderstorms in northwest Tennessee at 4pm.

For the exact same time frame, another model shows no rain in West Tennessee at all and all of the activity north of the Tennessee-Kentucky state line.

Most of the models side with the data that shows very little rain in West Tennessee but I'm not convinced that we'll get completely out of this one unscathed. What you need to do is stay weather aware! Those that live near the Tennessee-Kentucky border need to be especially vigilant today. I'll post radar updates throughout the afternoon to keep you posted on which route our weather decided to take.

So to summarize:

• Severe weather potential exists for northwest Tennessee this afternoon and evening
• Large hail and flash flooding will be possible if thunderstorms become severe but a large portion of West Tennessee may not see any rain at all today
• Thunderstorms will exit West Tennessee completely as they continue to move north after midnight

Tune in to WBBJ 7 Eyewitness News tonight for the latest forecast! 

Tonight's Risk for Severe Weather

NOTE: This blog post is pertaining to a chance for severe weather that is forecast 

for tonight, Wednesday, April 26th, 2017.

A broken line of thunderstorms is traveling across Arkansas and Missouri and is forecast to arrive in West Tennessee tonight. Those storms may arrive as soon as 7pm for parts of West Tennessee near the Mississippi River. Either way, tonight is a night to be weather aware!

Here's an animated image for what the radar could look like this afternoon and evening as the cold front moves in...

The graphic I posted last evening on the arrival time of these thunderstorms hasn't changed much, the storms will arrive after sunset for most of West Tennessee but could come as early as between 6-8pm for areas along the Mississippi River.

The risk for severe weather has increased since yesterday's outlook with much of West Tennessee under a slight risk (2 out of 5) and some areas of southwest Tennessee under an enhanced risk (3 out of 5). The primary concern is for some thunderstorms to produce damaging winds (winds gusting over 60 miles per hour) and and large hail (hail bigger than quarters).

There's a low threat for tornadoes but an isolated tornado near the Mississippi River seems worth watching out for this evening. One of the many data products I look at when making a forecast regarding the tornado probability is the Significant Tornado Parameter. This tool gives me an idea for how likely a tornado would be within a thunderstorm. I look for values above 1 but really start to consider tornadoes a more serious threat once values are 3 or 4 and above. Those values barely reach 2 near the Mississippi River but still indicate that this a risk worth monitoring. This data shows the values will stay below 1 for most of West Tennessee tonight.

These storms could leave a significant amount of rainfall in the area tonight as well, so flash flooding will be another concern.

So to summarize:

• Severe weather potential for West Tennessee tonight starting at 6pm near the Mississippi River 
• All forms of severe weather are possible though the threat for a tornado remains low
• Thunderstorms will exit West Tennessee completely between midnight and 2am as they cross the Tennessee River

Tune in to WBBJ 7 Eyewitness News tonight for the latest forecast! I'll go through each hour of the night and cover the latest updates to our severe weather risk.

Multiple Rounds of Strong to Severe Thunderstorms Heading for West Tennessee

NOTE: This blog post is pertaining to a chance for severe weather that is forecast for tomorrow, Wednesday, April 26th, 2017 as well as a couple other days on the 7-day forecast.

First things first - what a beautiful sunny day it is! There isn't a cloud in the sky over Jackson right now after having a wet weekend when 4" to 6" of rain fell in parts of West Tennessee! Unfortunately, today is one of the few - if not the only completely dry day that we may have for a little while. Wednesday night, Friday night, and Sunday are all days when we could not only have heavy rain, but severe weather as well.

Let's start with tomorrow...

A cold front will travel across Arkansas on Wednesday bringing heavy showers and thunderstorms to that area. As the cold front interacts with warm and humid air, it'll cause a risk for severe weather for most of that state. West Tennessee won't see the cold front until after sunset, so we'll be getting the leftovers of that system. 

Right now, West Tennessee is under a marginal to slight risk (1 to 2 out of 5) for severe weather Wednesday night which includes a threat for damaging winds, large hail, and an isolated tornado. The primary threat appears to be damaging winds for our area. If you have plans Wednesday evening, pay attention to updates on this forecast very closely, especially if you live in an area that is in the slight risk (yellow) area.

The Storm Prediction Center has also flagged our area for a risk for severe weather on Friday when a warm front moves through (Day 4) and on Sunday when another cold front moves through (Day 6). 

But if severe weather wasn't enough, I'm especially concerned with flash flooding happening in West Tennessee again! The GFS model is suggesting 1"-5" for West Tennessee with northwest Tennessee (namely Lake County) getting nearly 6" of rain over the next several days.

The Weather Prediction Center agrees with that suggesting a potential for excessive rainfall in West Tennessee over the next 7 days.

So, as always, stay weather aware! Keep watching our forecast for updates on what's ahead. Have a way to receive severe weather information including watches or warnings if they are issued. I'll keep you posted with another update on WBBJ 7 Eyewitness News!

Summary:

• Severe weather possible Wednesday night, Friday night, and Sunday
• All forms of severe weather are possible including a tornado during those days
• Excessive rainfall is expected over the next 7 days