Looking at he 12z HRRR model as well as some of the other NOAA/NWS higher-resolution model guidance and some of the AI/ML models, too, I wanted to offer an update on how things are shaking out.
First, the Radar as of this writing:
We have a line of storms from the Texas/Louisiana border all the way up to east of Memphis. Some of these storms are already severe. A few have tornado warnings. And I think we ahve had one tornado spotted on the ground, already, in northern Mississippi.
We ahve also already started to see some instability showers fire up in “cloud streets” moving from south-to-north with the mid-level and low-elev wind.
During previous events, some folks 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 do this to be helpful!’
I was convinced by folks, though, that others want to ‘help’ like I do – just differently.
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.
THE DATA
The morning data changes from 00z to 12z (that is 12 model runs of the HRRR model, three runs of the NAM & NAM3km model, and two meaningful runs of everything else) show a just-as-potent atmosphere as yesterday with some slight changes on the edges.
The 00z and 6z data suggested – nearly across the board – that we would be cooler and more humid with a higher dewpoint. At 730am we were at 75F with a dewpoint of 66F. Model guidance thought we would be closer to 72F with a dewpoint of 68F.
Two degrees of dewpoint doesn’t sound like a lot, but for severe weather events, it could be a ton.
So! Either the secondary warm front, with added moisture, is moving a bit slower or the push of Gulf moisture didn’t have quite as much moisture as the models thought.
I tend to think it is the latter since we know, through experience, that the HRRR and NAM models in particular are too warm and too humid, historically. We only need to look back to the “snow event that wasn’t” for many folks earlier this year when model guidance suggested we would have all of this moisture in place and I had to ruin everyone’s fun by saying, “sorry, the models stink at this part.”
As of this writing we are now 75F with a dewpoint of 68F. And as we get warmer today, it will allow for “space” to pack in more moisture, so I expect the dewpoint to rise a bit. Particularly between now at 11am.
What is interesting to me, though, is that much of the higher-res guidance continues to show limited low-level forcing ahead of the line of storms. Which, would – generally, and at a glance – limit the risk for tornadoes from the discrete supercells ahead of the line, as most of the forcing for ascent would be from the cloudbase and up. In this specific event, it may be less necessary given that the updrafts will be moving very fast, and in a sense, creating a vacuum effect under the cloud base, but it remains to be seen when the low-level surface-based forcing will arrive.
This could also suggest that storms may fire ahead of the line – a bit like a few events ago – from the “leading wake” ahead of the line.
Simply put, these are all things I’m trying to keep an eye on.
FAILURE MODE UPDATE
Well, we didn’t get as many storms overnight. So the “laying down of outflow boundaries as catalysts for storm initiation” is more off the board.
That means storms that do develop will have to wait for some sort of low-level or mid-level forcing to get moving. A bit like I mentioned above, that may limit the number of storms that fire ahead of the line as we don’t see a lot of that in the guidance right now.
And that would limit the risk for a wider spread of strong tornadoes. It doesn’t mean no one gets one, just that there are fewer opportunities to produce them.
We are also waiting for the surface area of low pressure to develop behind the current front. Most model guidance puts this in southeastern Arkansas by midday. The HRRR model shows it a bit farther southeast. This would mean – for us – a functional limit on the speed and potency of the surge of moisture northward. And that may also limit the distribution of storms and, thus, the potential for widespread high-end significant severe weather
REASONABLE WORST CASE SCENARIO
I think a reasonable ‘worst case scenario’ is that we have two or three storms in our area that have sufficiently strong updrafts to produce a strong tornado. Given the data from overnight, I laid out these two circled area and places that ahve enough redundancy from severe parameters across all model guidance to support a heightened concern for significant severe weather.
Given some of the 12z guidance, I don’t think there is reason to change those circles much.I could make the arguement, almost, for a third one to include parts of southern Perry and Greene counties, but that is clinging to some math I don’t have full confidence in.
Outside of our area is a different story. I haven’t taken the time to look, but I know there are other areas outside of southern Mississippi and Louisiana that will have to battle with the chance for strong tornadoes, too.
THE BOTTOM LINE
The latest data confirms that today’s atmosphere remains just as capable of producing severe weather as expected, with some slight adjustments in moisture and forcing details. While there are still some uncertainties about how storms will initiate ahead of the main line, the overall risk for strong tornadoes, damaging winds, and large hail remains high.
Key Takeaways from This Morning’s Update:
- A line of storms is already ongoing from the Texas/Louisiana border up through Memphis, with some storms already severe and at least one tornado reported in northern Mississippi.
- The moisture return is still progressing, with dewpoints rising—meaning conditions will continue to improve for storm development through midday.
- The main question remains how much storm development we will see ahead of the main line. If storms do form, they could have the potential for strong tornadoes.
- Two areas remain most concerning for strong tornado potential based on the latest model guidance. If you are inside these highlighted areas, be especially alert today.
What You Can Do Right Now (Before Storms Arrive):
Charge your phone in case of power outages. Make sure your weather alerts are turned on (NWS, weather apps, NOAA Weather Radio). Know where you’ll take shelter if a tornado warning is issued. Basements, storm shelters, or interior rooms on the lowest floor are safest. Talk to your family & friends. A quick message like “Hey, storms later today could be rough—do you have a way to get alerts?” can make a huge difference. Secure outdoor items that could become projectiles in strong winds. If you live in a mobile home, plan where you’ll go if a warning is issued. Mobile homes are not safe in tornadoes.
Final Thought:
This isn’t about panic—it’s about preparation. The goal is for everyone to be aware, have a plan, and take action if needed. The atmosphere is primed for storms; now, we watch to see how things unfold.
Stay safe, stay informed, and I’ll keep you updated throughout the day.
