State of the Chase Season: 2016 Edition

[JamesCaruso]

As I prepare to start my chase vacation this weekend, I appreciate the flurry of posts in this thread over the past two days.

Jeff's as always was very insightful and educational, and because I consider myself a novice forecaster even after 20 years, I was glad to see that he also mentioned the poor co-location of mid level flow and moisture, as well as the awful (I think he said "disgusting" - perfect description!) GFS for the week of 5/30 that I had mentioned in my earlier post. It had me a little down about my trip but I reminded myself, I don't need any big synoptically-evident setups, and we all know how the anticipated big days can disappoint or present problems of their own with chaser convergence, storms going up everywhere and interfering with each other, low visibility due to high moisture and low clouds, etc. I was encouraged by some of the other more optimistic posts about next week's prospects. I think it truly is a different perspective between the chase vacationers and those who live on the Plains; the latter tend to wait for the (relatively) "sure thing" because they know they will be there if/when such setups arise. One problem for me though is that having to identify likely mesoscale accidents largely exceeds my forecasting skills...

Interesting comment by Andy on how each year seems to have a consistent failure mode within that year. Drought is one thing, but why would troughs consistently exhibit VBV in a particular year? Difficult to comprehend...

I really am worried about that week of 5/30. I know the GFS is Fantasyland at that range, but is it completely off the wall? Is it still possible that it switches *completely*, from the jet stream being in Canada to showing a west coast trough? Or is it not likely to reverse completely, and more likely to be "right" about an unfavorable pattern to some degree? Note that COD's ERTAF says that the week of 5/30 will be "Average" for tornados, which certainly seems at odds with a midsummer jet stream location in Canada...

 

[Andy Berrington]

Interesting comment by Andy on how each year seems to have a consistent failure mode within that year. Drought is one thing, but why would troughs consistently exhibit VBV in a particular year? Difficult to comprehend...

To put it simply, short wavelengths/blocking are often the culprits. When flow gets blocked, you often get meridional flow in the mid/upper levels that leads to VBV. This was a big problem on 4/26. The height gradients this year have also been less than ideal owing to the lower heights at lower latitudes via ENSO forcing.

As for the upcoming pattern, I thought the 12z Euro looked pretty darn good next week, with several low amplitude waves with 50+ kt 500 mb flow rotating around the western longwave trough into a highly unstable warm sector across the Plains. Not to mention a pretty nice looking upslope setup on this upcoming Sunday (5/22). Thinking that there will be a lull probably in early June, whether it picks up after that into mid June (a highly climo favoured period in previous Nino springs) will probably make or break the season for many (and also the chances at reaching near average tornado counts for the year).

The +PDO certainly has been an issue, but I'm thinking the persistent ridging over AK/W Canada (perhaps partly forced by the +PDO) may have more to do with some of the issues we've seen especially this year, since this teleconnects to downstream troughing over Hudson Bay/E Canada. If we can get rid of some of that (at least the AK ridging), I think there will be a better chance going forward.

 

[James Gustina]

2014 had the triple threat of crap moisture return almost all season, trough timing off by 6 hours or more and thermonuclear caps originating from the source region of Chihuahua and New Mexico. I can't say I'm crazy about the subtlety of the upper-level features in the coming week but we've certainly seen worse since 2012 produce good tornadoes.

Sent from my XT1080 using Stormtrack mobile app

 

[Royce Sheibal]

Just a note about the importance of early season rainfall on tornadoes. The drought that prevailed in 2014 totally ruined many a good day early season down in TX/OK/KS, and even into NE. Later that season areas of Nebraska had up to 20 inches (or more) of rain in the month leading up to a nearly two week-long severe sequence. My 60 year old home had the basement seriously flood for the 1st time ever. Most of that rain was due to leftover crapvection from failed KS/OK storms moving into NE.

As soon as the strong ridge over the SE US built in, as it does in late spring, a cold front stalled in the upper plains, acting as the main catalyst. It stayed there for most of June, with temps on the south side near 90 every day, and Td's only around 65 forecast. It seemed to be a heavy cap-scenario, but the front and localized outflows from overnight convection caused strong moisture convergence which boosted local Td's to the 70-75 range in the hours shortly before initiation.

This setup has become my 'second theory' for outbreak creation in the central plains, versus the traditional Colorado negative tilt trough. Late season monster capes, good boundary moisture, and low-level meso-interaction may prove to be just as valuable to predict north-side outbreaks as more traditional indexes are in the south-side. I would say that this difference in forecasting preference has been one of the major reasons why local and national forecasts have had such bad skill in the central and northern plains in the last few years, as one dominant pattern and understanding of weather shifts toward another.

I think there is a good chance of this setup repeating itself over the next week or two, but with the front likely a bit further south stalling in KS/MO this year. As our understanding of boundary layer moisture advances, hopefully forecasting skill will improve for these scenarios.

 

[Tim Paitz]

Wow, the 6Z GFS had CAPE exceeding 6000 J/KG in central OK at 00Z on Thursday! However, the newest run shows a couple of pockets of 6000+ CAPE in Kansas City and a small area of southern OK. Also, there's a lot of lift. Like I said before, the winds are out of the southwest except in south-central OK, where it's south- southeast. Dewpoints are as high as 80 in this area as well.


I know, it's a week out but still, if it were to be a chase day based on the current data, I'd go along 35 just north of the Red River.

 

[Brett Nickeson]

I don't have much to add technically right now, but I'm in the unfortunate position of having to choose which days to take off work next week to chase. I can probably only take off three days at the most right now due to a heavy workload, and the current forecast is showing potential significant severe weather all five days of the next work week. Being from Omaha, with the targets appearing to largely be in the Oklahoma/TX/southern KS area, I can't make a quick drive back home for work on a single day, so I'm basically stuck with whatever decision I make on Saturday. I'm intrigued by the GFS and, less so, the Euro in bringing some stronger midlevel flow on Thursday and Friday. However, the timing could end up such that the chase area would be east of I-35 which may as well not even be a chase day at that point. Monday, Tuesday, and Wednesday offer decent setups, but the midlevel flow is fairly anemic and height rises appear probable at least a day or two.

Hopefully something reveals itself soon. I'd rather not make the wrong decision and drive 11 hours one way for the worse of the week's setups.

 

[Greg McLaughlin]

2016 will go down in the record books. What a week this has been so far! Tornadoes 5 straight days and we aren't done yet. A lot less people are complaining now.

 

[Michael Gavan]

Legendary.


Sent from my iPhone using Stormtrack mobile app

 

[Damen Winslow]

Unless, you've had to work and miss these setups like some of us!

 

[Jeff Duda]

2016 will go down in the record books. What a week this has been so far! Tornadoes 5 straight days and we aren't done yet. A lot less people are complaining now.

In what way?

 

[Ethan Schisler]

Hopefully June/July can come through with some northern plains action. Especially for those of us that couldn't get out this past week. 2016 is still going down as my worst year since I've started chasing (2009). Last year I got some of my best tornadoes in June/July so I'm not completely calling things off yet, but the main season sure has been disappointing from my end of things. Its been a plains chasers wet dream this year, not so much for someone living 12 hours away....lol.

 

[Brett Roberts]

This past week has been a perfect example of one that isn't really "record breaking" in any quantifiable or meteorological sense, but was still one of the best Plains chasing stretches in quite a few years. Day after day of photogenic, slow-moving supercells and tornadoes in the best terrain available in the southern Plains. This is the kind of classic late season streak we've been missing for several years S of I-80, especially if you throw out the late May 2013 period because so much of it was in bad terrain and urban areas.

Looking ahead, today through Sunday offer some mediocre/flawed potential, and then it isn't pretty heading into next work week. On the bright side, the GFS/CFS are somewhat consistent of late in depicting at least one more favorable pattern sometime around June 10-15. In my opinion, even if the next 10-12 days offer few/marginal chase opportunities, one more active period with a couple quality days in June would be enough to make this one of the best seasons of the decade aside from 2010.

 

[Jeff Duda]

This past week has been a perfect example of one that isn't really "record breaking" in any quantifiable or meteorological sense, but was still one of the best Plains chasing stretches in quite a few years. Day after day of photogenic, slow-moving supercells and tornadoes in the best terrain available in the southern Plains. This is the kind of classic late season streak we've been missing for several years S of I-80, especially if you throw out the late May 2013 period because so much of it was in bad terrain and urban areas.

All a matter of perspective. If you caught the gems of the past few days, sure, this has been an amazing stretch. I personally will come off this stretch having chased 3 of the last 6 days that offered potential and with < 10% of the subjectively-judged goodness that many others caught. So the way I see it, this period wasn't actually all that huge. From an objective standpoint, most days did not offer widespread high quality structure or tornadoes. There was only a single storm on Saturday that had great structure, but not so hot in the tornado department. Sunday had quite a few supercells, but I haven't seen any even halfway decent structure shots, and most of the tornadoes were weak and short lived. Seems like the winners on Sunday were those on the storm near Spearman. Monday was an overall bust except for the one storm that produced a tornado near Woodward. Again, quality, but nothing spectacular. Tuesday was clearly the big day of the week, so no more needs to be said there. Wednesday was a single storm with one impressive tornado (I don't count the BS storm after dark in NC OK). Thursday was an almost complete bust regionwide. We see stretches like this almost every year, just not always right smack dab in the middle of the plains.

I should also add that basically every single trough that has come through the Plains has been a total bust. This has been a year where chasing only "the day" would've resulted in extreme disappointment. The best days this year have been anything but "the day". And there have really been no days where multiple large crowds scored on multiple storms separated by large distances. It's basically been one "gem" storm every day there was quality.

 

[Tim Paitz]

In what way?

Worst year for moderate risks lol.

 

[Brett Roberts]

All a matter of perspective. If you caught the gems of the past few days, sure, this has been an amazing stretch. I personally will come off this stretch having chased 3 of the last 6 days that offered potential and with < 10% of the subjectively-judged goodness that many others caught. So the way I see it, this period wasn't actually all that huge. From an objective standpoint, most days did not offer widespread high quality structure or tornadoes. There was only a single storm on Saturday that had great structure, but not so hot in the tornado department. Sunday had quite a few supercells, but I haven't seen any even halfway decent structure shots, and most of the tornadoes were weak and short lived. Seems like the winners on Sunday were those on the storm near Spearman. Monday was an overall bust except for the one storm that produced a tornado near Woodward. Again, quality, but nothing spectacular. Tuesday was clearly the big day of the week, so no more needs to be said there. Wednesday was a single storm with one impressive tornado (I don't count the BS storm after dark in NC OK). Thursday was an almost complete bust regionwide. We see stretches like this almost every year, just not always right smack dab in the middle of the plains.

I should also add that basically every single trough that has come through the Plains has been a total bust. This has been a year where chasing only "the day" would've resulted in extreme disappointment. The best days this year have been anything but "the day". And there have really been no days where multiple large crowds scored on multiple storms separated by large distances. It's basically been one "gem" storm every day there was quality.

I can definitely see that perspective. This has been a very bad year so far in terms of high-predictability, "big" setups, much like last year (and even 2010, to a lesser extent).

This past week's quality tornadoes were certainly localized, for the most part. Still, trying to look at it objectively, I feel like it was a very high quality chase week. Saturday offered a very obvious target which produced a photogenic supercell with decent tornadoes (I wasn't out, though). Sunday, despite clearly favoring the Spearman storm for multiple photogenic tornadoes, offered visible tornadoes that were at least respectable in chase quality on numerous storms (Scott City, Howardwick, Turkey/Lakeview). Monday's best daytime tornado was in WWR, but the structure down south around dusk was spectacular (even featuring a cone underneath at one point) and then there were very impressive tornadoes just after dark. Tuesday needs no comment, and then Wednesday was another unequivocal career day for anyone on the right storm from early on (which, to be fair, was the only sustained supercell of the day). As a whole, the week has been a chasecationer's dream, but no gimme for choosy locals by any means. Objectively, I think it's fair to say this was an amazing opportunity in terms of what happened, even if it was difficult for most chasers to nail said opportunity. I think what really pushes this stretch into classic territory for me is that it was all well W of I-35 in some of my favorite chase country (except Wednesday, but NC KS is much better than similar longitudes further south), which has been so hard to get ever since the big drought that started in 2011.

It sure would be nice if June gives us at least one more classic setup than what we've seen so far. Even if it's not a true outbreak, an obvious localized setup like Bowdle would be great. High end forecast events that actually verify continue to be the big weakness of the past few years.