A quick note that this kind of forecast isn’t something that you can etch into stone. Or even in pen. I’ll do my best to give as accurate a forecast as possible at this point for different parts of south Mississippi, but as this storm system evolves, this may need to be changed.
So, please – PLEASE! – don’t simply look at this forecast now, and assume that you can wait until “XX” time tomorrow to check back in with the weather.
From the SPC
The Storm Prediction Center has pegged part of the area with a Moderate Risk for severe storms. That is a “4” on the 1-to-5 scale where “5” is the highest risk for the most significant severe weather.
Within that risk area, the individual threats break down like this:
The black hatched area in each of the above maps indicates an area where “significant” severe weather can occur. That means things like wind gusts in excess of 70mph, hailstones up to the size of baseballs, and tornadoes stronger than EF2 in strength.
County-by-county timeline breakdown
I will try to break things down county-by-county here. Generally the overall forecast is the same across our area with only tiny wrinkles here and there. In general, the greatest concern for severe weather will be between 1p and 5p Wednesday across the whole area.
Northern counties
Simpson County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line may make it through by 8pm
Smith County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line should be through by 9pm
Jasper County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line should be through this area by 10pm
Clarke County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – Isolated severe storms may persist through 7pm here. After that point, this is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line should be through this area by 11pm
The Highway 84 Corridor
Lawrence County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 9pm.
Jeff Davis County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 9pm.
Covington County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Jones County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Wayne County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado (up to EF3 in strength)
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 11pm.
The Highway 98 Corridor
Walthall County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 9pm.
Marion County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Lamar County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Forrest County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Perry County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 11pm.
Greene County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 11pm.
The Highway 26 Corridor
Pearl River County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 10pm.
Stone County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 11pm.
George County
5am-11am – Passing clouds with an isolated storm possible. Any storm that forms would have the potential to be strong, with heavy rain, frequent lightning, gusty wind and small hail
11am-5pm – Isolated severe storms possible during this time. Storms may not be widespread, but they could be potent. The main concern with storms during this time is heavy rain, frequent lightning, wind gusts up to 60mph, hail up to the size of tennis balls, and the potential for a tornado.
5pm-11pm – This is when a line of storms passes through the area bringing heavy rain, frequent lightning, wind gusts up to 60mph, and the potential for brief tornadoes. The line of storms should pass through here by 11pm.
Updraft Helicity streaks
A lot of you that have been following these updates over the years (seven! holy moly!) have learned that the Updraft Helicity streaks within the model guidance can do a good job to help highlight where the most potent storms may be. This isn’t a perfect estimate, but it is a good first look at what may occur and a good “ballpark” for overall coverage.
The maps above are courtesy of Pivotal Weather and they highlight three different estimates – from lower threat to higher threat – within the modeling. The interesting thing to note is that all three produced a potent storm that moves from SW to NE right through the heart of south Mississippi.
Again, I want to stress that none of the above maps are “right” or “wrong” but instead are used as guidance to come up with a forecast for where the highest potential may develop…
Above is the areas that show to have the highest potential for seeing the strongest storms for south Mississippi only.
If you live within the orange – and particularly the red – I would really encourage you to keep extra tabs on the weather during the day on Wednesday. This doesn’t mean if you live outside of these areas you can let your guard down, but it means that if you are inside of these areas, you should pay a bit more attention to Mother Nature.
In the orange circled area, Bay Springs, Leakesville, New Augusta, Purvis, Collins and tAylorsville, and points nearby and points between.
The red circled area includes places like Hattiesburg, Petal, Ellisville, Laurel, Waynesboro, and Richton. Points nearby and points between.
Karrie Meter – Boom or Bust
I’m going to try this for the first time publicly. Hopefully this makes sense. If not, feel free to ask questions as this isn’t the most intuitive thing to follow…
The nice thing about creating and now running the Karrie Meter is that I can tweak with the data to see how things may look if the model data is inaccurate. For example, today I ran the Karrie Meter from the GFS computer weather model. Then I ran it with an atmosphere that is 10-percent more “potent” and another where the atmosphere is 10-percent less “potent” to get an idea about how things may look.
You can see how in some places a change of 10-percent doesn’t change much, while for others it drops the number a full category. And in some places two!
What does this mean?
This shows you just how ‘perfect’ the setup needs to be tomorrow to get the significant severe weather to develop in some places. For south Mississippi, this shows that places like Jasper, Clarke and Wayne counties may have an increased risk for severe weather if the model data has underplayed the numbers by as little as just 10-percent. At the same time, folks in Marion county are looking at basically the same potential for severe weather, regardless of if the models got it right or were to high by 10-percent.
The Bottom Line
Showers storms and the potential for severe weather will last most of the day on Wednesday.
The timeline of events on Wednesday leave the area with an “all day” event where the potential for storms exists for longer than 12 hours and may start before some people wake up and linger around until after some people go to bed.
This doesn’t mean it will be storming all day long. There may be times during the day on Wednesday where it is actually “nice” outside. But, there may also be times when it is raining sideways, lightning is flashing and hail is pummeling your rooftop. Determining when your specific house or workplace will see rain, storms and severe weather is still a bit out of reach.
For now, just make sure you have your NOAA Weather radio setup with fresh batteries. Make sure it is set to the right channel and, if capable, that it is set to alert you when a warning is issued for your county. Also, download a weather app to your phone that will ping you when a warning is issued for your area. Having multiple ways to receive a warning is like setting two alarms to make sure you actually get up in the morning! Redundancy is key!
