Severe Weather 2018

[rolltide_130]

I never said it wouldn't happen, I said it's rare to see multiple high-end threats in one season. Yes, we will have additional Dixie threats, some may be significant, this year. That is a given, as it is every year.. My point was the volatility we saw going into yesterday is hard to replicate multiple times in a season.. that doesn't mean it won't happen.

 

[MichelleH]

April 15, 2011

April 27, 2011

And that's all I'm going to say about that.

 

[Fred Gossage]

There have only been a couple of times, even looking pre-1950, in the Alabama tornado database... where there was more than one F4+ day in one particular year... 1920 is a big example, and there could've been another one or two. However, there are countless examples where there have been days in the spring with a couple to few F2-F3 tornadoes... only to go on to have another day with a higher-end event / outbreak with at least one F4 or higher.

The confluence in the Northeast and into the North Atlantic just off the coast, and the tendency for troughing in southeast Canada and eastward, is pretty firmly locked in now. That helps to do a few things. It suppresses the subtropical ridging further south. It helps the upper flow stay more low amplitude. It also helps direct the upper jet at a lower latitude to, aimed more at Dixie (even if there are deviations with that from time to time, with individual system to system). I can't say for sure that we'll get another significant day here, but the door is not only open... but because of those larger scale factors mentioned, it is a more substantial possibility than it usually is.... and I wouldn't 100% rule out this thing yesterday not being the worst one here of the spring season... but that is nothing more than speculation, and is no cause for panic or anything like that.

 

[CheeselandSkies]

I didn't know this...

Pulled from the other thread, but I count 7 of those 25 periods from 2012-present. It's almost like the atmosphere is still on a post-4/27/11 hangover, because it hasn't produced a proper tornado season since then. There's a day here, a day or 2 there with long stretches of particularly hostile patterns locked in between (massive central CONUS ride, or cold eastern CONUS trough). The bigger events have been largely mesoscale-driven, with something going awry with almost all the potential big synoptically evident outbreaks (with the exception of 2012 which was basically March 2 and April 14, and April 28 in 2014). The only consistently active period in that stretch was the back half of May 2013 including of course Moore, Rozel and El Reno, and that was very central OK/KS from I-70 south centric with little activity in other parts of the Plains/Midwest.

Got to wonder when is the next season with a 7-14 day period of activity with multiple MDT to HIGH risk caliber events (that perform) spread across varying regions of the Plains/Midwest like May 4-10, 2003, May 22-30, 2004, or pretty much all of May through June 12, 2008.

Not sure I like the sound of your post Fred as it would seem to imply a reduced severe threat for the upper Midwest this spring as systems get crushed by cold air slamming in from the north/west instead of further deepening as they lift out of the Rockies.

I realize every decade has its active years and its quieter years, but this second decade of the 21st century seems different than any in the record when it comes to severe weather activity, at least after 2010. 2011 had its uber-hyperactive April centered from the MS river eastward, followed by a May "season" that was basically three days, two of which featured extremely violent events.

Every year since then has been what I would call "inactive with a couple active days here and there" or "with stretches that looked like they might be active but had wrenches thrown in" (thinking particularly of that stretch in May 2015 culminating in May 16, which *could* have been one of the biggest west-of-I-35 Plains events since the 1990s).

 

[Fred Gossage]

I think it might just mean a slightly delayed ramp up for up there. We'll see. Just speculation at this point... but you can't ignore that consistent confluence to my area's northeast.

 

[Kory]

Pulled from the other thread, but I count 7 of those 25 periods from 2012-present. It's almost like the atmosphere is still on a post-4/27/11 hangover, because it hasn't produced a proper tornado season since then. There's a day here, a day or 2 there with long stretches of particularly hostile patterns locked in between (massive central CONUS ride, or cold eastern CONUS trough). The bigger events have been largely mesoscale-driven, with something going awry with almost all the potential big synoptically evident outbreaks (with the exception of 2012 which was basically March 2 and April 14, and April 28 in 2014). The only consistently active period in that stretch was the back half of May 2013 including of course Moore, Rozel and El Reno, and that was very central OK/KS from I-70 south centric with little activity in other parts of the Plains/Midwest.

Got to wonder when is the next season with a 7-14 day period of activity with multiple MDT to HIGH risk caliber events (that perform) spread across varying regions of the Plains/Midwest like May 4-10, 2003, May 22-30, 2004, or pretty much all of May through June 12, 2008.

Not sure I like the sound of your post Fred as it would seem to imply a reduced severe threat for the upper Midwest this spring as systems get crushed by cold air slamming in from the north/west instead of further deepening as they lift out of the Rockies.

I realize every decade has its active years and its quieter years, but this second decade of the 21st century seems different than any in the record when it comes to severe weather activity, at least after 2010. 2011 had its uber-hyperactive April centered from the MS river eastward, followed by a May "season" that was basically three days, two of which featured extremely violent events.

Every year since then has been what I would call "inactive with a couple active days here and there" or "with stretches that looked like they might be active but had wrenches thrown in" (thinking particularly of that stretch in May 2015 culminating in May 16, which *could* have been one of the biggest west-of-I-35 Plains events since the 1990s).

Probably a decadal oscillation regime shift post-2011. 10 in that list came from the positive Pacific decadal regime of the mid-1970s until the late 1990s.

 

[CheeselandSkies]

Probably a decadal oscillation regime shift post-2011. 10 in that list came from the positive Pacific decadal regime of the mid-1970s until the late 1990s.

Interesting if that entire period was a +PDO, since the early 1980s had some western Plains events that are classics in the annals of old-school chasing, and the early and mid 1990s had some very active stretches widespread across the Plains and Midwest.

Even more interesting, now that I look I see one of those stretches each in 1991, 1999 and 2008, three years which I would consider hugely active for tornadoes. Mind blown.

 

[Fred Gossage]

I think we're gonna have to start watching the period around Good Friday really closely. There's a reasonably consistent signal the past few runs in the GFS and even Euro of a system that bares close watching... and some runs of the GFS have even looked rather substantial at the synoptic level. Way too early to try to pin down any details, even on the larger scale, but there is a growing signal that we may have another storm system we have to watch very carefully in the heart of Dixie Alley.

 

[jmills]

The pattern overall is looking active for severe weather.

 

[ARCC]

I think we're gonna have to start watching the period around Good Friday really closely. There's a reasonably consistent signal the past few runs in the GFS and even Euro of a system that bares close watching... and some runs of the GFS have even looked rather substantial at the synoptic level. Way too early to try to pin down any details, even on the larger scale, but there is a growing signal that we may have another storm system we have to watch very carefully in the heart of Dixie Alley.

Won't have a problem with low level moisture. The GFS is already advertising DPs 63-69 across the south over a week away.

 

[rolltide_130]

The pattern overall is looking active for severe weather.

Late April looks significant.. just in time for final exams at UAH as always.

 

[tennessee storm chaser]

Late April looks significant.. just in time for final exams at UAH as always.

Yep liking looks on today’s gfs. Step in the right direction. Long range severe

 

[NWMSGuy]

Yep liking looks on today’s gfs. Step in the right direction. Long range severe

Additional Flooding concerns to speak of as well.

 

[Equus]

I'm going to be in California the last weekend of April... hah, I will be upset to miss something going on here at that time. Time to sit in a hotel room refreshing Radarscope I suppose

 

[akt1985]

Late April looks significant.. just in time for final exams at UAH as always.

It wouldn’t be Panoply without a threat of severe weather. Hopefully, it won’t storm the day of the Cornbread Festival in South Pittsburg, Tennessee.

 

[rolltide_130]

Not really in TW's primary domain, but the plains may have a potentially substantial threat this weekend..

 

[CheeselandSkies]

Well that's the NAM going PDS TOR NAMbusters on everything as usual, but there should be at least some severe weather in the Plains this weekend into early next week. Primary hazards/ceiling/potential chase quality TBD.

 

[Fred Gossage]

Well that's the NAM going PDS TOR NAMbusters on everything as usual, but there should be at least some severe weather in the Plains this weekend into early next week. Primary hazards/ceiling/potential chase quality TBD.

It's probably overplaying the early next week ordeal some, maybe even by a good deal, but it's kinda hard to rag on the NAM when it and the SREF have consistently outperformed everything else in our area of the country since at least our winter storm here back in early December... and if anything, wasn't aggressive enough a few days out with the severe weather parameters for both the February 25th tornado event in the MidSouth and our tornado outbreak here back on Monday...

 

[SilentShadow87]

I would say the Jacksonville tornado was rated liberally, probably more liberally than what I would have given it, but it's also consistent with the DI on the Enhanced Fujita Scale. The roof was torn off of a mid-rise building which has expected winds of 136 mph (marginal EF3) and upper bound winds of 158 mph (high-end EF3). The official wind estimates are 140 mph, which is pretty close to the expected wind speeds based on the DI.

I might have gone with a high-end EF2 rating for Jacksonville myself, and I feel like there were stronger tornadoes on February 24 which were rated EF2, but that's a matter of my opinion. I think it was within reason, if pretty liberal, to go with a low-end EF3 rating.

 

[rolltide_130]

I would say the Jacksonville tornado was rated liberally, probably more liberally than what I would have given it, but it's also consistent with the DI on the Enhanced Fujita Scale. The roof was torn off of a mid-rise building which has expected winds of 136 mph (marginal EF3) and upper bound winds of 158 mph (high-end EF3). The official wind estimates are 140 mph, which is pretty close to the expected wind speeds based on the DI.

I might have gone with a high-end EF2 rating for Jacksonville myself, and I feel like there were stronger tornadoes on February 24 which were rated EF2, but that's a matter of my opinion. I think it was within reason, if pretty liberal, to go with a low-end EF3 rating.

The EF-3 rating was assigned due to damage that occurred in Nances Creek, which is just E of Jacksonville. This is also where the velocity maximum occurred, and if you were to base it solely on the velocity maximum it was a high end EF-3 to borderline EF-4.

Jacksonville proper got very fortunate that the tornado didn't hit peak intensity here. Things could have been exponentially worse if the tornado was a mid to high end EF-3 or even EF-4 when it was in the city itself.