• Welcome to TalkWeather!
    We see you lurking around TalkWeather! Take the extra step and join us today to view attachments, see less ads and maybe even join the discussion.
    CLICK TO JOIN TALKWEATHER

Severe WX Severe threat 3/30-3/31

Im amazed at the widespread mid to upper 60s dewpoints for this time of the year this event. There's a mild possibility it's undermodeled as well. Your looking at a potential extremely unstable atmosphere for late March standards in the deep south. We got a few more days to iron on a consensus with the globals before looking at the finer details mesoscale models. But I really don't like how abundant the moisture is. Doesn't look like there's a wedge to save us this time lol
 
Grand Poo Bah said:
Ask and you shall receive... Man, this was time consuming! I should say I guess it depends on how you define verification?

The day 6 outlook on 03/18 called for "thunderstorms with a threat for isolated large hail (2 inches or larger) and severe gusts (58 mph+) are expected to develop along the northern edge of the moist sector"

Here's the storm reports for 03/23. There was no hail 2 inches or larger, and 4 of the wind reports specified 60-80 mph winds. Though, there were two reports of 3 and 1 downed powerlines, and around a dozen downed trees. There was also an EF1 tornado that knocked down a few trees and powerlines. So I'd say the wind prediction maybe verified, but the hail didn't?

View attachment 37219View attachment 37214

On 02/27 there was a day 6 15-30% risk, and a day 7 15% risk issued. The day 6 called for "the potential for multiple rounds of severe convection including supercells, clusters, and likely an eventual squall line will likely bring a threat for all severe weather hazards including strong tornadoes." The day 7 was less specific but called for "
Low to mid 60s dewpoints in the presence of a very strong wind field will support a large area of severe weather threat"

Here's the storm reports for 03/04. There were 26 tornado reports but no strong tornadoes (all were EF1 or less), and 15 separate severe wind gusts (58 mph+) reported, with max straight line winds reaching 70-90 mph. Too many reports of downed trees and powerlines to count. An image of hail was reported with one being large (3 inches) and the rest being 1.5 inches. So for this one, the strong tornado risk didn't verify, severe wind gusts absolutely did, and the large hail is iffy but single isolated report could count as borderline?

View attachment 37218View attachment 37215

Storm reports for 03/05. Three severe wind gusts reports of 60-80mph, one downed electrical pole, and several reports of trees downed. An EF1 and EF0 tornado. 0 hail reports. Interesting report of "several rail cars pushed off their track" near Richland, SC. I'd call this one borderline as well, but the rail cars report is very interesting and may be evidence of isolated verification.

View attachment 37217View attachment 37216

And we all know how the 03/09 Day 6 and 7 panned out. 100% undeniably verified and then some. This is the first time i've looked at storm reports since the day after the event. 170 tornado reports is just absolutely bonkers.

View attachment 37222View attachment 37223
View attachment 37224View attachment 37225
Click to expand...
Uhh, all of those verified almost exactly to what a 15% risk for severe weather within 25 miles of a given point should. A 15% at D7 does not automatically mean "outbreak". It just means a higher confidence than usual of some kind of severe weather at that range. Those outlooks do not divide the percentages into specific kinds of severe weather.

There's a reason they do not outline significant severe areas that far in advance.
 
As someone who has done a fair amount of forecast verification for my research/job, those forecasts are just about as good as you're going to see at D7 for something as temporally short as severe weather.
 
Grand Poo Bah said:
Ask and you shall receive... Man, this was time consuming! I should say I guess it depends on how you define verification?

The day 6 outlook on 03/18 called for "thunderstorms with a threat for isolated large hail (2 inches or larger) and severe gusts (58 mph+) are expected to develop along the northern edge of the moist sector"

Here's the storm reports for 03/23. There was no hail 2 inches or larger, and 4 of the wind reports specified 60-80 mph winds. Though, there were two reports of 3 and 1 downed powerlines, and around a dozen downed trees. There was also an EF1 tornado that knocked down a few trees and powerlines. So I'd say the wind prediction maybe verified, but the hail didn't?

View attachment 37219View attachment 37214

On 02/27 there was a day 6 15-30% risk, and a day 7 15% risk issued. The day 6 called for "the potential for multiple rounds of severe convection including supercells, clusters, and likely an eventual squall line will likely bring a threat for all severe weather hazards including strong tornadoes." The day 7 was less specific but called for "
Low to mid 60s dewpoints in the presence of a very strong wind field will support a large area of severe weather threat"

Here's the storm reports for 03/04. There were 26 tornado reports but no strong tornadoes (all were EF1 or less), and 15 separate severe wind gusts (58 mph+) reported, with max straight line winds reaching 70-90 mph. Too many reports of downed trees and powerlines to count. An image of hail was reported with one being large (3 inches) and the rest being 1.5 inches. So for this one, the strong tornado risk didn't verify, severe wind gusts absolutely did, and the large hail is iffy but single isolated report could count as borderline?

View attachment 37218View attachment 37215

Storm reports for 03/05. Three severe wind gusts reports of 60-80mph, one downed electrical pole, and several reports of trees downed. An EF1 and EF0 tornado. 0 hail reports. Interesting report of "several rail cars pushed off their track" near Richland, SC. I'd call this one borderline as well, but the rail cars report is very interesting and may be evidence of isolated verification.

View attachment 37217View attachment 37216

And we all know how the 03/09 Day 6 and 7 panned out. 100% undeniably verified and then some. This is the first time i've looked at storm reports since the day after the event. 170 tornado reports is just absolutely bonkers.

View attachment 37222View attachment 37223
View attachment 37224View attachment 37225
Click to expand...

Uhm, all of these look worthy of the risk they had. SPC putting a slight risk out days ahead doesn't mean it will forsure be a big event. It means it looks like will be at least a slight event (which these all were), with a higher ceiling possible. Some of these examples of under-performing reports are affected by timing changes once the event got closer, so some of the event started the night before (3/4 event started late the night before with 150+ reports in the few hours before midnight, which also caused the 3/5 event to have fewer reports, because the storms were further East (over the ocean) than it looked like they would be days prior (very common). And on 2/23 you state there was no 2+ inch hail, but there in fact was multiple 2+ in reports of hail and a couple 2.5+. See filtered reports. That event also affected some of the least populated areas of S AR/N MS the most, so you aren't going to get as many reports because of that alone.
 
andyhb said:
Uhh, all of those verified almost exactly to what a 15% risk for severe weather within 25 miles of a given point should. A 15% at D7 does not automatically mean "outbreak". It just means a higher confidence than usual of some kind of severe weather at that range. Those outlooks do not divide the percentages into specific kinds of severe weather.

There's a reason they do not outline significant severe areas that far in advance.
Click to expand...

My comments have been in regards to the sentiment from some people that a day 7 risk is inherently something extreme, or means a huge severe weather outbreak is imminent. I'm also asking if the bar for issuing 15% this far out has lowered, due to the how many day 6/7 risks we've seen this year compared to the last 20 years? That was my whole point, which was overlooked. I'm still curious, so if anyone knows the answer it'd be appreciated!

Your second point is exactly what i've said in other comments as well. A 15% risk is by all accounts, a low probability, so even if nothing happened, if the models were predicting severe weather 7 days out, it's justified.
andyhb said:
As someone who has done a fair amount of forecast verification for my research/job, those forecasts are just about as good as you're going to see at D7 for something as temporally short as severe weather.
Click to expand...

Thanks for the info! This is pretty cool insight for a lay-person like myself. I wasn't sure if the specific predictions contained in the messaging is what was verified, or if it was more about the overall severe weather threat. I figured it was the former, which is why I said they didn't verify. Once again, it goes back to my original point that a lot of day 6/7s have been issued this year compared to previous years, and finding it interesting.

It's starting to feel like people are assuming the worst with a lot of my comments, and I shouldn't be participating in these discussions. I've been trying to bring up interesting observations, to learn more about weather/forecasting, and keep getting dragged for those observations like I'm spreading misinfo. You could've just explained verification without all the hassle... Why even bother requesting proof for a side note in my original comment when you already knew the answer? You're a graduate student in meteorology and verification is literally your job. I WANT insight from someone with your qualifications. It's the whole reason I posted that comment!
 
Last edited:
Grand Poo Bah said:
My comments have been in regards to the sentiment from some people that a day 7 risk is inherently something extreme, or means a huge severe weather outbreak is imminent. I'm also asking if the bar for issuing 15% this far out has lowered, due to the how many day 6/7 risks we've seen this year compared to the last 20 years? That was my whole point, which was overlooked. I'm still curious, so if anyone knows the answer it'd be appreciated!

Your second point is exactly what i've said in other comments as well. A 15% risk is by all accounts, a low probability, so even if nothing happened, if the models were predicting severe weather 7 days out, it's justified.


Thanks for the info! This is pretty cool insight for a lay-person like myself. I wasn't sure if the specific predictions contained in the messaging is what was verified, or if it was more about the overall severe weather threat. I figured it was the former, which is why I said they didn't verify. Once again, it goes back to my original point that a lot of day 6/7s have been issued this year compared to previous years, and finding it interesting.

It's starting to feel like people are assuming the worst with a lot of my comments, and I shouldn't be participating in these discussions. I've been trying to bring up interesting observations, to learn more about weather/forecasting, and keep getting dragged for those observations like I'm spreading misinfo. You could've just explained verification without all the hassle... Why even bother requesting proof for a side note in my original comment when you already knew the answer? You're a graduate student in meteorology and verification is literally your job. I WANT insight from someone with your qualifications. It's the whole reason I posted that comment!
Click to expand...
No one is assuming the worst with your comments, but if you're going to make claims that SPC/etc. is busting repeatedly with forecasts, I will ask you to back up those claims. This would be the same with anyone here.
 
Grand Poo Bah said:
It's starting to feel like people are assuming the worst with a lot of my comments, and I shouldn't be participating in these discussions. I've been trying to bring up interesting observations, to learn more about weather/forecasting, and keep getting dragged for those observations like I'm spreading misinfo. You could've just explained verification without all the hassle... Why even bother requesting proof for a side note in my original comment when you already knew the answer? You're a graduate student in meteorology and verification is literally your job. I WANT insight from someone with your qualifications. It's the whole reason I posted that comment!
Click to expand...

Grand Poo Bah said:
It's also interesting the SPC has issued more 15% 6-7 day outlooks this spring already than all the previous years combined (iirc). 2 of the 3 we've had haven't verified and never looked like huge threats on the models. Maybe a change in policy to make up for a lack in manpower with recent cuts?
Click to expand...
I don’t think you should feel that way man. I think really the only issue with your statement was the part in bold that you presented as fact. Feel free to ask questions all day long, we definitely encourage free conversation.
 
ColdFront said:
I don’t think you should feel that way man. I think really the only issue with your statement was the part in bold that you presented as fact. Feel free to ask questions all day long, we definitely encourage free conversation.
Click to expand...
Always ask questions! I know a lot of the nerds (non-derogatory), myself included, tend to throw around a lot of abbreviations and jargon, but if anyone is ever unsure of what something means, ask away, someone in here is usually able to answer!
 
ColdFront said:
I don’t think you should feel that way man. I think really the only issue with your statement was the part in bold that you presented as fact. Feel free to ask questions all day long, we definitely encourage free conversation.
Click to expand...
Clancy said:
Always ask questions! I know a lot of the nerds (non-derogatory), myself included, tend to throw around a lot of abbreviations and jargon, but if anyone is ever unsure of what something means, ask away, someone in here is usually able to answer!
Click to expand...
I appreciate this dudes. This is a pretty amazing community and i've been fascinated by the amount of collective weather and scientific knowledge here.
 
I'm here too if anyone has any questions. I may not be able to answer some, but I'll know where to find it. I guess I'm just throwing that out there.
 
7 day's out fo coarse, but KLZK looks to be starting to give it some legs at this range.

Area Forecast Discussion
National Weather Service Little Rock AR
350 PM CDT Mon Mar 24 2025

While all modes of severe weather will be possible,
quarter sized hail and 60 mph winds appear to be the primary hazards
for now. Once the smaller scale environment can be resolved in later
forecasts, we`ll know whether the mesoscale environment and
antecedent cloud cover enhance or suppress the threat for severe
storms on Saturday across Arkansas.

On Sunday the strong upper trough is expected to move from the
intermountain west over the south and central plains, spreading
strong large scale forcing for ascent to the east and southeast over
Arkansas by Sunday afternoon and evening. This trough will also send
a frontal boundary across the state as well as a much stronger wind
field aloft compared to earlier in the weekend. With nothing ahead
of the front to scour out the deep Gulf moisture in place, there
should be an ample combination of heat, humidity, and deep layer
wind shear to support a more focused and widespread severe weather
threat across Arkansas.
Once again all modes of severe weather will
be possible, however the number of severe storms and their
capability for producing severe weather both look to be enhanced
Sunday afternoon and evening. Whereas Saturday`s severe weather
threat looks more dependent on smaller scale, or mesoscale details
that are difficult to resolve more than a couple of days out,
Sunday`s severe weather setup looks to be more obvious on a larger,
or synoptic scale. As a result, speaking broadly, Sunday seems to
pose the biggest severe weather threat to Arkansas in the forecast.
The details matter quite a bit of course, so this could change as we
resolve smaller scale forecast details, but either way it will be
important to monitor updated forecasts as we approach the upcoming
weekend.
 
Grand Poo Bah said:
It's also interesting the SPC has issued more 15% 6-7 day outlooks this spring already than all the previous years combined (iirc). 2 of the 3 we've had haven't verified and never looked like huge threats on the models. Maybe a change in policy to make up for a lack in manpower with recent cuts?
Click to expand...
Grand Poo Bah said:
I'm not even remotely qualified to make that call. Just pointing out what we've seen this year so far. I'll let someone else answer your question, but gotta remember a 15% risk of severe weather means there's an 85% chance of none. They can't go any higher than 30% this far out, and the reason is it's just impossible to predict anything with much certainty when even the best models are still changing with every run. 15% risk has seemed perfectly reasonable (all 4 times they've used it this year) to me.
Click to expand...
Grand Poo Bah said:
I wasn't even remotely making that claim... I was saying the SPC has issued more day 6/7 risks this year than previous years. which they have.

I also said they didn't verify, which according to official verification standards (that you have unique access to), wasn't true. A large hail threat didn't verify with one, and a strong tornado threat didn't verify with the other, but the overall severe weather risk still verified. I didn't need to back anything up, you could've just told me, and I would've been like "yep. ok! that makes sense." Even so, the reason for bringing it up, was about the broader point that they haven't seemed to need slam dunk model runs to issue such extended severe weather outlooks this year.

How does it seem like I was saying the SPC was "repeatedly busting"? I'm in complete support of them issuing more day 6/7 risks. And I was interested in why they've decided to this year. Did you miss my next comment which I made less than 15 minutes later?

View attachment 37235

It doesn't matter... I'm getting absolutely demolished with these ratios, and the point has been made. Best wishes.
Click to expand...
I'm confused. You say that the forecasts are not verifying first and that there might be some change in issuance policy because of politics (this is a touchy subject for me, admittedly). Then you say 4 times they have used them, they were fine? Your initial statement included none of the further context provided later, which does clear things up, but I don't really think I was taking things out of context with my initial responses.
 
You must log in or register to reply here.
Back
Top