Severe WX Severe Threat 17-18 March 2021

[Austin Dawg]

I'm aware of that, nor do I expect things to always line up as predicted. We seem to be on a streak, though, of things never lining up as predicted, at least when it comes to these anticipated high-end events.

I'm not trying to throw shade on anybody here. I just heard a lot of flak today and it was quickly shut down by those who are more educated.

 

[Evan]

Yes, there is no gap in my enthusiasm haha. I haven't seen that video in years. You were a noob though.

I certainly was. Crazy that feels like it was 5 years ago when it was well over a decade ago.

There was a discussion many pages back about how long people have been members of Talkweather. I joined the original site operated by John Oldshue back around 98/99 I think. I can't remember when you joined but I remember being fascinated that your parents went chasing WITH you. Heck, I think you may have hit even been able to drive alone then! My parents would've never done something like that. Hahaha.

Kind of crazy to think I've been on this forum for more than half my life.

 

[Evan]

I'm aware of that, nor do I expect things to always line up as predicted. We seem to be on a streak, though, of things never lining up as predicted, at least when it comes to these anticipated high-end events.

Sort of related...

I have wondered why the amazing progress modeling has made over the past 20 years has sort of seemed to hit a wall in some areas. Don't get me wrong; I think it has continued to improve in many different areas, but it seems certain things are still a struggle with certain models at times.

Hard to complain too much when thinking of comparing the old ETA to the NAM or the RAP from 15 years ago to today's HRRR. I do think it is a matter of time before we see substantial improvement, however, as countless billions in natural disasters and a stunning amount of lives loses could be saved with additional progress.

Meteorological research, modeling, and a lot of specific research areas relating thereof are criminally underfunded. Some day soon that plight is going to attract the right attention and deep-pockets. It really frustrates me at times, to think about the missed opportunities out there, because there's simply not enough attention given to properly funding the research and projects out that could make a major impact.

 

[Equus]

The preponderance of violent tornadoes on enhanced and moderate days instead of high days makes me wonder if, lately, violent tornadoes have been far more driven by mesoscale factors in marginal days than large scale synoptics. Obviously excepting days like 4/27, but it seems like the large scale ascent in major synoptically evident outbreak event, and the questionable wind profiles in a good chunk of them or not aligning with the LLJ, isn't doing is any storm mode favors to develop long tracked violent tornadoes. It's the very small scale stuff in only moderately favorable days that seem to really crank out the violents

 

[warneagle]

The preponderance of violent tornadoes on enhanced and moderate days instead of high days makes me wonder if, lately, violent tornadoes have been far more driven by mesoscale factors in marginal days than large scale synoptics. Obviously excepting days like 4/27, but it seems like the large scale ascent in major synoptically evident outbreak event, and the questionable wind profiles in a good chunk of them or not aligning with the LLJ, isn't doing is any storm mode favors to develop long tracked violent tornadoes. It's the very small scale stuff in only moderately favorable days that seem to really crank out the violents

Yeah, I mean, the synoptically-evident violent events have always been the exception rather than the rule. Obviously our ability to assess that is somewhat limited by the fact that we only have a few decades of reliable historical data (and less than 15 years of data assembled according to the current ratings standards), but the majority of violent tornadoes don't happen in massive, synoptically-obvious events like 4/3/74 and 4/27/11; they happen in more conditional environments where the mesoscale factors were decisive. We just aren't at a point in our scientific understanding of the atmosphere where we can predict how those features will evolve with the necessary precision to avoid busts, so it's going to happen sometimes in these setups that are conducive to violent tornadoes but require the mesoscale conditions to develop favorably.

4/27/11 I think warped some people's expectations for significant tornado events where they expect anything that draws a high risk to be a nailed-on major outbreak and feel mislead when we don't get a dozen violent tornadoes out of it when that was never the norm. I'm obviously not an expert so these are just armchair takes, but I think those expectations are influenced by availability bias. 4/27/11 is the reference point for a lot of people (especially those who became interested in the weather because of that event), so that becomes their standard for a major outbreak rather than recognizing that it was an extreme outlier, so any conditional setup that underperforms its potential seems like a major Forecasted Convective Amplification Deficiency rather than what it was: a conditional event that might or might not happen depending on less predictable factors.

Of course, there's a role for the forecasters and the science communicators as well in adequately conveying that uncertainty, and there have been some obvious cases recently where the forecasters expressed a level of confidence that, in retrospect, wasn't justified. Of course the public doesn't understand probability and uncertainty very well ("omg u said 10% chance of rain and it rained at my house u r an idiot"), but uncertainty is an integral part of science and expressions of high confidence have to be judicious. It's a really delicate balancing act of creating the right amount of concern in the public and not more or less, because people who don't pay serious attention to this stuff aren't going to understand when you convey high confidence in something that doesn't happen because of a conditional failure mode. I guess all you can really do is take the data and try to understand what happened so you can make a better forecast next time.

 

[CheeselandSkies]

Yeah, I mean, the synoptically-evident violent events have always been the exception rather than the rule. Obviously our ability to assess that is somewhat limited by the fact that we only have a few decades of reliable historical data (and less than 15 years of data assembled according to the current ratings standards), but the majority of violent tornadoes don't happen in massive, synoptically-obvious events like 4/3/74 and 4/27/11; they happen in more conditional environments where the mesoscale factors were decisive. We just aren't at a point in our scientific understanding of the atmosphere where we can predict how those features will evolve with the necessary precision to avoid busts, so it's going to happen sometimes in these setups that are conducive to violent tornadoes but require the mesoscale conditions to develop favorably.

4/27/11 I think warped some people's expectations for significant tornado events where they expect anything that draws a high risk to be a nailed-on major outbreak and feel mislead when we don't get a dozen violent tornadoes out of it when that was never the norm. I'm obviously not an expert so these are just armchair takes, but I think those expectations are influenced by availability bias. 4/27/11 is the reference point for a lot of people (especially those who became interested in the weather because of that event), so that becomes their standard for a major outbreak rather than recognizing that it was an extreme outlier, so any conditional setup that underperforms its potential seems like a major Forecasted Convective Amplification Deficiency rather than what it was: a conditional event that might or might not happen depending on less predictable factors.

Of course, there's a role for the forecasters and the science communicators as well in adequately conveying that uncertainty, and there have been some obvious cases recently where the forecasters expressed a level of confidence that, in retrospect, wasn't justified. Of course the public doesn't understand probability and uncertainty very well ("omg u said 10% chance of rain and it rained at my house u r an idiot"), but uncertainty is an integral part of science and expressions of high confidence have to be judicious. It's a really delicate balancing act of creating the right amount of concern in the public and not more or less, because people who don't pay serious attention to this stuff aren't going to understand when you convey high confidence in something that doesn't happen because of a conditional failure mode. I guess all you can really do is take the data and try to understand what happened so you can make a better forecast next time.

Here's what I said in response to a private message about 4/27:

4/27/11 was so extreme that it stood out even among other high risk days. It's highly unlikely that a setup like that would ever be given a moderate risk in the modern era (Coincidentally, in 1974, the first Super Outbreak was initially given the equivalent of a moderate risk on the primitive convective outlooks being issued then, but the state of the science was nowhere near as advanced).

My post was more commenting on the long streak we're on of high risk days failing to produce particularly notable tornado events, with those tending to fall on days like last Easter or the Beauregard day in 2019, with lower forecast confidence but ultimately higher-impact outcomes. Prior to this streak, high risk days generally verified pretty well with significant outbreaks even aside from 4/27/11, such as the 11/17/13 Illinois/Indiana event, 3/2/12 (Henryville, IN EF4), 4/24/10 (Yazoo City, MS long-track EF4 among others), 2/5/08 (Super Tuesday outbreak), 5/24/11 (Plains outbreak, "El Reno 1" EF5 & Chickasha/Goldsby EF4s), etc.

 

[Chris3024]

NWS Huntsville confirms an EF1 in Cullman Co. last night.

That is from the 2nd circulation that wasn’t warned I believe. They still haven’t released information about the earlier warned storm that occurred around 650pm

 

[TH2002]

Finally some damage pics out of Burnsville, AL:


Mobile home destroyed, vehicle tossed

Full video:

 

[mike36]

Yeah, I mean, the synoptically-evident violent events have always been the exception rather than the rule. Obviously our ability to assess that is somewhat limited by the fact that we only have a few decades of reliable historical data (and less than 15 years of data assembled according to the current ratings standards), but the majority of violent tornadoes don't happen in massive, synoptically-obvious events like 4/3/74 and 4/27/11; they happen in more conditional environments where the mesoscale factors were decisive. We just aren't at a point in our scientific understanding of the atmosphere where we can predict how those features will evolve with the necessary precision to avoid busts, so it's going to happen sometimes in these setups that are conducive to violent tornadoes but require the mesoscale conditions to develop favorably.

4/27/11 I think warped some people's expectations for significant tornado events where they expect anything that draws a high risk to be a nailed-on major outbreak and feel mislead when we don't get a dozen violent tornadoes out of it when that was never the norm. I'm obviously not an expert so these are just armchair takes, but I think those expectations are influenced by availability bias. 4/27/11 is the reference point for a lot of people (especially those who became interested in the weather because of that event), so that becomes their standard for a major outbreak rather than recognizing that it was an extreme outlier, so any conditional setup that underperforms its potential seems like a major Forecasted Convective Amplification Deficiency rather than what it was: a conditional event that might or might not happen depending on less predictable factors.

Of course, there's a role for the forecasters and the science communicators as well in adequately conveying that uncertainty, and there have been some obvious cases recently where the forecasters expressed a level of confidence that, in retrospect, wasn't justified. Of course the public doesn't understand probability and uncertainty very well ("omg u said 10% chance of rain and it rained at my house u r an idiot"), but uncertainty is an integral part of science and expressions of high confidence have to be judicious. It's a really delicate balancing act of creating the right amount of concern in the public and not more or less, because people who don't pay serious attention to this stuff aren't going to understand when you convey high confidence in something that doesn't happen because of a conditional failure mode. I guess all you can really do is take the data and try to understand what happened so you can make a better forecast next time.

I have to admit I was guilty of this on high risk days. I remember reading a blog about April 27 from a meteorologist named Bob Davies. He said in that blog that the atmospheric conditions on that day were probably as optimal as we will EVER see.

https://www.google.com/url?sa=t&source=web&rct=j&url=http://davieswx.blogspot.com/2011/05/27-april-2011-extraordinary-environment.html%3Fm%3D1&ved=2ahUKEwiGp7aak73vAhVruVkKHVByAwkQFjAAegQIAhAC&usg=AOvVaw313XPMgU1d_vJNpMdwrY8V

 

[speedbump305]

So while it’s safe to assume 2021 might not be an active year for tornadoes, think back to a couple of years, most active years start the year off slow and then get really active in later march, april, may, june, and the last three months. I have a feeling this will be a long season

 

[maroonedinhsv]

So while it’s safe to assume 2021 might not be an active year for tornadoes, think back to a couple of years, most active years start the year off slow and then get really active in later march, april, may, june, and the last three months. I have a feeling this will be a long season

I must have missed something - who said that's a safe assumption?

 

[speedbump305]

I must have missed something - who said that's a safe assumption?

Oh crap. that just sounded wrong. i worded it wrong. I’m sorry. i do not wish to make it sound like i support death in tornadoes. i hate it when tornado outbreaks happen. they are very sad and life shattering. I’m very sorry. i should’ve worded it wrong

 

[thundersnow]

Oh crap. that just sounded wrong. i worded it wrong. I’m sorry. i do not wish to make it sound like i support death in tornadoes. i hate it when tornado outbreaks happen. they are very sad and life shattering. I’m very sorry. i should’ve worded it wrong

I don’t think that was the issue.

It was more the “safe assumption” that 2021 might not be an active season, when peak is still ahead.

 

[speedbump305]

I don’t think that was the issue.

It was more the “safe assumption” that 2021 might not be an active season, when peak is still ahead.

Ohhhh. Yeah your right.

 

[Casuarina Head]

Even with the limiting factors that ended up getting into place, immediately on the unstable side of the warm front in central Alabama yesterday, an EF4+ parameter space did get into place and there were cellular tornadic storms that tracked through that parameter space. There were just other factors that kept them from realizing their true potential.

In your view, what were the primary limiting factors that came into play on St. Patrick’s Day?

 

[Kory]

Up to 21 tornadoes and counting in Alabama from last Wednesday.

 

[warneagle]

Up to 21 tornadoes and counting in Alabama from last Wednesday.

Yeah, "Forecasted Convective Amplification Deficiency" is definitely relative here. The moderate risk area absolutely didn't Forecasted Convective Amplification Deficiency.

I'm also curious about the fact that there were several cases where supercells kept going right back over the same area (Selma, east of Laurel, south of Tuscaloosa). Were there boundaries in place there or could it be something topographical?

 

[pohnpei]

Now the sixth largest tornado outbreak in AL in terms of tornado numbers. Part of the reason owing to the better survey technology nowadays.
With no EF3 rating tornado in this event, the last 5 tornado high risk overall had 1 EF3 tornado.(Pleasant Farm 5/20/2019)

 

[warneagle]

Now the sixth largest tornado outbreak in AL in terms of tornado numbers. Part of the reason owing to the better survey technology nowadays.
With no EF3 rating tornado in this event, the last 5 tornado high risk overall had 1 EF3 tornado.(Pleasant Farm 5/20/2019)

Just looking at it superficially, I'm a bit surprised the Chilton Co. tornado didn't get at least low-end EF3, but it's possible the construction of those houses was pretty poor and didn't merit anything above EF2.

 

[pohnpei]

Just looking at it superficially, I'm a bit surprised the Chilton Co. tornado didn't get at least low-end EF3, but it's possible the construction of those houses was pretty poor and didn't merit anything above EF2.

Yes, it gives me a feeling that Chilton tornado was at least low end EF3 tornado giving the first look at the damage. House was gone, vehicle was thrown and debris carried long distance. So it must be construction problem again. It seems to me that most NWS tend to go lower wind speed to poor construction houses than several years before.