I don’t want to bury the lead here so I want to start with this: It will be windy. Ahead of the storms, during the storms and after the storms. If you have any bird feeders out or umbrellas on the porch, you’ll want to try and bring those in Tuesday night.
MAIN CONCERNS
||| Between Wed 1p through Thurs 1a |||
Brief heavy rain
Localized flash flooding
Frequent lightning
Wind gusts up to 65mph (perhaps higher)
Small Hail
A few tornadoes
Beyond that, be warned. For more than just weather. You are probably going to see some scary maps on social media (and maybe on TV in some spots). The NAM model this afternoon and evening is coming back with some pretty gaudy numbers.
I’ll give you two quick examples:
The SigTor map on the left shows some decent values in the 2s and 3s. That is plenty for a threat for tornadoes. And then on the right is a Skew-T sounding, just a quick peek at the atmosphere and it shows a “PDS TOR” as a ‘possible hazard type’ in the bottom right corner. Both of those are for about 7p on Wednesday night.
And that may ‘feel’ pretty scary. Seeing bright colors on a map and seeing a “PDS TOR” as a possible hazard type may shoot your stomach into your throat. And while, yes, there is a chance for tornadoes. And yes those tornadoes could be up to EF-3 in strength, I have some good news. The good news is that things may not be quite as beefy as shown, despite the pretty colored maps and Skew-T data may estimate.
Tornadoes on Wednesday are going to be heavily dependent on how much instability is present ahead of and near the front. Very important to remember.
Could a few brief/weak tornadoes happen? I think they will. Could strong tornadoes happen Wednesday? They could. Just not “likely” is all. Could EF-5 tornadoes happen? I suppose. But it is far less likely.
The NAM model (shown above) tends to run a bit “hot” with storms. That is to say, it tends to over-estimate the environment during severe weather situations. More heat, more moisture, more instability. It is a good model. And knowing this doesn’t make it a bad model, it makes it a model that has flaws. And it is important recognize those flaws.
I will say, though, that one thing that caught my attention with the 18z run of the model this afternoon was the storms breaking apart toward the southern side of the line. This is one thing I talked about last week as a possibility. I mentioned if that happens, they may have an easier time getting more organized and supercellular. Doing so would increase the tornado threat. And we saw a hint of that with storms – and subsequent tornado – that went through New Orleans.
The NAM is doing a similar thing this week.
Notice, in this rendering of the model, that the southern line of storms farther west breaks apart and splits into a few supercells. Will this happen? That is still TBD. I would lean toward “it isn’t as likely” but it is gaining a bit of extra attention. And it is also worth monitoring. Closely.
The 00z HRW-ARW model showed a similar development this morning. The HRW-FV3 is also known to run a bit “hot” with data, too. So you have the two models that are known to over-estimate things a bit showing a similar outcome.
This may not give us insight into the outcome directly, but it can help indirectly. If things are “over-performing” versus other model guidance, we can lean toward the NAM and HRW-FV3.
The other thing worth noticing is the ‘lean’ of the line itself. While the Euro has shown a more vertical line and the GFS has shown a more angled approach the last few days, the NAM is in the middle. That lean may help for bowing segments to produce brief and weak tornadoes while it pushes through the area.
So even if things don’t get quite as rambunctious with supercells, the line itself may spawn a few brief tornadoes with things line up this way, relative to the inflow.
The Karrie Meter & CIPS Analogs
I ran the Karrie Meter based on the NAM model from above. Because I wanted to see how it would handle data that was “hot” from the NAM. And it came back…. underwhelmed.
The reason? The Karrie Meter takes mid-level instability into account. And model guidance, while “robust” appearing, lacks a strong core of instability between 850mb and 500mb. That limits the Karrie Meter final number.
It isn’t perfect. But it a good helper to dig under the riff-raff.
Showing numbers between 3 and 5 is a good indicator that severe weather is possible. And that there will likely be at least a few severe storms. Where they will be and if one will be near you we won’t know until the day of.
Getting a better idea about the risk from the CIPS Analogs spells out the higher chance for severe weather across much of Mississippi and parts of Louisiana. With the highest tornado risk across southern Mississippi.
The CIPS Analogs has been pretty bullseyed in that section for severe weather and tornadoes for the last six days. Another reason to keep tabs on the forecast as we get closer to Wednesday.
During this (and previous) event, people have asked if there is a way to “‘help’ or ‘say thanks’ for all of the forecasting work I do. For the longest time I said, ‘nah! I just like doing this! You know, to help!’ But I was recently convinced that others want to ‘help’ in their own way, too.
And their way of helping, or simply saying ‘thank you’ is with a donation to the blog to help keep it running – or to help keep me running. So I’ve added this link. If you are one of those people, let me say thank you to YOU.
County-by-County Timeline
A quick reminder that this timeline doesn’t mean that the entire time it will be raining and storming. It is an attempt to give you the best window of opportunity for storms to be near you. A three to four hour window may only feature rain and storms for 30 minutes. But the goal is to highlight a window where the threat is higher than at other times.
This timeline is likely to change a bit in the coming days, too. So please check back for an update tomorrow as more data comes down and we get a better handle on things. For the moment, here is a look at the threats by general population:
During the highlighted times below
EVERYONE — Brief heavy rain, lightning, and wind gusts up to 45mph
MOST SPOTS — Heavy rain, lightning, wind gusts up to 50mph
SOME PEOPLE — Heavy rain, localized flooding, wind gusts up to 65mph, small hail
FEW PLACES — Heavy rain, localized flooding, wind gusts exceeding 65mph, small hail, a tornado
Louisiana
St. Helena Parish
Wednesday 1p-4p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 4p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 4p-7p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 7p-10p — Storms ending. Turning cooler and breezy.
Tangipahoa Parish
Wednesday 1p-4p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 4p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 4p-7p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 7p-10p — Storms ending. Turning cooler and breezy.
Washington Parish
Wednesday 1p-4p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 4p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 4p-7p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 7p-10p — Storms ending. Turning cooler and breezy.
Livingston Parish
Wednesday 1p-4p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 4p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 4p-7p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 7p-10p — Storms ending. Turning cooler and breezy.
St. Tammany Parish
Wednesday 1p-4p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 4p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 4p-7p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 7p-10p — Storms ending. Turning cooler and breezy.
Mississippi
NEAR I-20
Copiah County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Simpson County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Smith County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Jasper County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Clarke County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
HIGHWAY 84 CORRIDOR
Lincoln County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Lawrence County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Jeff Davis County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Covington County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Jones County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Wayne County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
HIGHWAY 98 CORRIDOR
Pike County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Walthall County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Marion County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Lamar County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Forrest County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Perry County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Greene County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
HIGHWAY 26 CORRIDOR
Pearl River County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Stone County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
George County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
COASTAL MISSISSIPPI
Jackson County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Harrison County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Hancock County
Wednesday 2p-6p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 6p-10p — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Wednesday 10p-Thursday 2a — Storms ending. Turning cooler and breezy.
Alabama
Sumter County
Wednesday 4p-8p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 8p-Thursday 2a — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Thursday 2a-6a — Storms ending. Turning cooler and breezy.
Choctaw County
Wednesday 4p-8p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 8p-Thursday 2a — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Thursday 2a-6a — Storms ending. Turning cooler and breezy.
Washington County
Wednesday 4p-8p — Isolated showers with few rumbles of thunder developing early, very few (if any) storms may be strong to severe before 6p. Main threats with any storm will be heavy rain, frequent lightning, gusty wind, small hail, and a tornado can not be ruled out.
Wednesday 8p-Thursday 2a — Showers and storms likely, many strong with a handful severe. Main threats with stronger storms will be very heavy rain, frequent lightning, wind gusts up to 70mph, hail up to the size of quarters, and the potential for a tornado (up to EF3 in strength).
Thursday 2a-6a — Storms ending. Turning cooler and breezy.
