State of the Chase Season: 2015 Edition

[Robert Forry]

To your point @Jeremy Pérez, and this is just one snapshot of one day. Yeah, the H5 flow isn't 100 kts but its not 25 either. I'm liking next week more and more. Looking forward to finally putting down the 55 hour work week and getting out there.

 

[chrisbray]

Looks like for the first week or so at least, June will be pretty boring weather-wise.

 

[Jeff Duda]

FWIW, the CFS has been showing a lot of widespread "hot" activity throughout June and into July as well, as seen in the chiclet chart from Greg Carbin. I've noticed the CFS has not performed very well this spring as far as picking up on the bigger troughs with lead time. In fact, for some of the bigger days, the CFS didn't show any consistent signal until as late as 3 or 4 days out. In the past it has given some indications as far out as 10-12 days. It seems to suggest the first 10 or so days of June will be inactive or very spotty (signal seems to get pretty coherent and accurate within 10 days or so) with activity increasing afterward. I still think June will have a lot of tornadoes since it's climatologically favored. The EML source region is still very wet and only in the last few days have I started to notice 10+ C 700 mb temps coming out of that area, so I think capping, or rather lack thereof, will continue to remain an issue until much later next month (barring a sudden and complete cessation of precip across the entire southern and central US), but I think it will gradually improve. I can't speak to the trend for troughing and cyclogenesis events. They indeed tend to get weaker and less frequent during June, and the CFS seems to indicate pretty much normal 500 mb heights during the late June-early July period, with some cool 850 mb temps in the southern plains area.

 

[Mike Marz]

Chris, I would say that next week actually looks to have some possibilities. GFS is forecasting a lot of cape and some good 850s on a few of the evenings next week. It does look like capping could be an issue. The 500s and 250s are far from impressive, but this is a pretty decent looking sounding from the GFS 06z run earlier.

I think if some things work out, next week has some possibilities on a couple of days.

 

[Dan Robinson]

I have to think that the prospects for an active June would be above average this year. Climatology favors an increase of extreme instability days in the southern/central Plains. Normally, that CAPE goes to waste due to the thermonuclear cap usually in place by early June that far south. That's assuming a western trough and southwest midlevel flow of at least 20-30kts over the Plains. That said, I've never personally observed or read about a season quite like this one, so beyond that I'm really not sure what to expect. It will be interesting to see how it plays out.

 

[Andy Wehrle]

Looks like for the first week or so at least, June will be pretty boring weather-wise.

Maybe for where you are, but I'm on vacation next week and based on the model watching I've been doing and and this morning's SPC Day 4-8 outlook, there's a high likelihood I'm headed to the Dakotas!

It's not a wowzer of a trough by any means, but the Canadian (TX) tornadoes were a good reminder you don't need that to get great storms & tornadoes, AND you don't have to race them at 40-60 MPH! 500MB flow couldn't have been much above 30 kt in that area at the time.

I don't like driving, so I'm loath to do 6+hour trips for less than surefire AOA moderate risk setups, but another thing this year has reminded me of is how much the terrain in Wisconsin sucks for chasing. So many hills and trees, there are very few places to get an open view of the sky. I used to tell myself "It can't be worse than Dixie Alley, and people chase there, AND bag violent tornadoes flying through at 50+MPH without getting themselves killed," but actually I think it is (worse).

 

[Robert Forry]

It's not a wowzer of a trough by any means, but the Canadian (TX) tornadoes were a good reminder you don't need that to get great storms & tornadoes, AND you don't have to race them at 40-60 MPH! 500MB flow couldn't have been much above 30 kt in that area at the time.

Exactly Andy.
Picked a good week to be off to chase. The Dakota's into MN and southern WI will be OK for me. No longer of a ride out for me than it is to the central Plains from here.

 

[Patrick Martin]

My chasecation starts on 6/4 and I'm actually feeling pretty good about prospects. The GFS has been consistent at least on a broad scale with the "on hour" runs (12z/0z) showing plausible chances for storms in sight. It's certainly not epic outbreak or classic setup, and more along the lines of high cape/low'ish shear type of deal through next week, but I'll take it. We don't limit ourselves on distance, so if it's ND or NM, does not matter, and being able to disconnect from the 55 hour weeks in the office in favor of a long mile road trip suits me just fine. The early part of June has consistently been the time when we have chased, and climatology has historically rewarded us with storms to see/chase, even in the less than stellar years.

 

[Andy Berrington]

If the jet with the Aleutian low can make it to the West Coast, there might be something bigger in the cards after the first week of June (not to say there won't be activity before then). Warm ENSO Junes/Junes coming out of a Nino tend to be active than their cold counterparts, there are a number of recent years to verify that (1992, 1995, 1998, 2003, 2010). If you get the combination of the seasonally deep boundary layer moisture with a moderate but not thermonuclear EML, that could be a recipe for a powder keg with any decent trough ejection.

 

[Andy Wehrle]

Perhaps I'm the one who spoke too soon. This coming week is looking steadily less impressive on the GFS until maybe Saturday/Sunday. The models continue to tease us this year, more so than I've seen in previous years it seems.

 

[James Gustina]

Not overly impressed with anything this week sans maybe Tuesday. Patterns like this are always a real pain in the rear to figure out which low-key day will do it. I'm not particularly enamored of driving up to the Dakotas/Montana for any of the next few days.

 

[Dan Robinson]

I'm not seeing any reason to embark on my third Plains trip any time soon, so I've gone back into regular work/local chase mode for the time being. All I see in the short and long term (for at least 2 more weeks) is a continuation of what we've seen all season: multiple problematic setups that each *could* produce something big, but no clear "quality" days. The only way to succeed with this pattern is to either chase all of the days, or choose a few of them and hope to luck out. I can't afford the former, and don't like the latter - it's essentially like gambling on a long shot. I have plenty of long shots here in the Midwest.

I know someone's going to score this week, just like some did in NM last week. I just don't know which day will do it. These kind of seasons are for the all-season chasers or the person who has to take a fixed chase vacation, I've just accepted I won't ever be a part of those type of days. I'm not complaining - the upside for my type of chasing is that I'll be there for the future 4-14-12s, the 5-3-99s and the 4-26-91s. I just have to put up with some years like this one.

 

[James Gustina]

Kind of interesting note on Thursday, it's almost a dead ringer for May 25, 2012. Sky-high T/Td spreads, deep EML, triple point positioned in W-Cntrl Kansas with the sfc low back in SE Colorado. The upper-levels were far and away better on May 25 with stronger H5 winds but it looks like a classic late-spring triple point day on the central High Plains should everything continue as is.

 

[Jeff Duda]

I certainly don't know what may happen during the rest of the traditional chase season, but the GFS has been very consistent in showing a period of strong, mostly zonal, flow across the northern half of the US, starting early this week, and continuing perhaps well into next week as well. There aren't any real big troughs showing up, but there is a strong zonal mid-level jet for the time of year showing up. If it kinks at all, it could fire off a bigger event given the high moisture content across the country over this period. There look to be subtle embedded shortwaves in the flow, but predictability on those is pretty poor, as the location and timing seems to change pretty rapidly with successive GFS runs. If one of those is well-timed, there could easily be a big event somewhere north of I-80 over the next 7-10 days.

The big fly in the ointment as far as predictability goes is what happens with Invest 91 in the GoM right now. Newer forecasts show it pushing farther west than before. It eventually joins up with the jet to the north and moves on east, but could evolve into a shortwave trough by then, thus providing for some interesting dynamics east of the Mississippi later this week or this weekend.

While organized severe weather is usually done by this time of year for I-70 and south, several GFS runs have been showing a building ridge across the Rockies with enhanced WNW/NW flow making it almost down to I-70 in the medium range. NW flow events can't be ignored, especially as we near mid-summer with very humid air masses in place and only weak cold fronts associated with northern-stream disturbances. The post-frontal airmass can remain convectively unstable long enough for things to happen behind fronts at this time of year. A couple different GFS runs have shown pretty decent shear across N KS along with sufficient shear for supercells and tornadoes along a front.

Is "the season" over? Mostly, but there are always straggler type events late in the year. Hell, look what happened in Iowa in early July last year.

 

[JeremyS]

The GFS, and now the NAM that we're starting to get in range, have been showing some high CAPE/ good shear days coming up throughout this coming weekend and next week north of I-70. The biggest problem, which hasn't really been there all year so far, is a potential nuclear cap setting up. I've been seeing 850s of 20 C and 700s of 15 C in the areas of the best CAPE and shear. However, the 12Z GFS today seemed to decrease the amount of CINH on Sunday's and Monday's setup. I love those 5k CAPE days!

 

[calvinkaskey]

For the Eastern USA it has been pretty crappy so far and I'm including MI, OH, IN, AR, TN. A lot of states have about half or less annual average of tornadoes and hail reports are particularly low in northeast US including Oh and Va.

 

[Robert Forry]

Actually, MI has already seen half (I beleieve) of its annual average of tornadoes. That occured on 6/22-23. Of course, we only average 18-19 a year LOL. Around here the season doesn't end until the snow flies. As long as there's moisture around, decent instability, and some easterlies off the Lakes, we always stand to see some TORs right up through the fall.

 

[James Gustina]

Thought I might as well "reactivate" this thread since we're progressively moving towards the possible fall season in hopefully a month or two. The summer pattern has been pretty textbook with the main branch of the jet stream over the Rockies further north and ridging out hard over the central and southern Plains. It doesn't seem like anything interesting outside of Canada is shaping up in the near future which means it might be a bit of a haul before we start seeing the jet dip back south with the onset of autumn.

 

[Jeff Duda]

I can't remember a season that featured legitimate big time tornado/supercell setups this late into the year (speaking mainly of the events up in IL last week). Definitely seems to be related to the strengthening El Nino. Also helps when much of the central US has been remained soaked due to drenching rains since basically April. We were probably really close to seeing some outbreaks in some of these July events.

 

[James Gustina]

Really hoping that the southern Plains manage to pull out a solid fall season. I have no illusions about breaking the summer doldrums early like we did in 2014 with September 1st. Having a 1998-esque fall season would not surprise me with how moist it's been through the entirety of the summer.

 

[Adam Lucio]

My spidey senses tell me we could see a big early fall event this year. Something like a 9-22-06 or 10-18-07. The juice seems to be consistently in place, and with the ongoing El Nino the jet seems more energized than normal. Sooner or later climatology is going to begin to take over and the cold air will make a push southward, which should only further strengthen the jet and help generate some strong cyclones. Hell, we just saw an anomalously deep cyclone produce a potential 3 hour long tornado in Canada 2 weeks ago.

So yea, totally won't be surprised to see a higher end event in the early fall. Interesting to see how things unfold as we slowly begin the transition between seasons and the jet comes back south.

 

[Jonathan Beeson]

My spidey senses tell me we could see a big early fall event this year. Something like a 9-22-06 or 10-18-07. The juice seems to be consistently in place, and with the ongoing El Nino the jet seems more energized than normal. Sooner or later climatology is going to begin to take over and the cold air will make a push southward, which should only further strengthen the jet and help generate some strong cyclones. Hell, we just saw an anomalously deep cyclone produce a potential 3 hour long tornado in Canada 2 weeks ago.

So yea, totally won't be surprised to see a higher end event in the early fall. Interesting to see how things unfold as we slowly begin the transition between seasons and the jet comes back south.

While not exactly "prime" chasing territory, don't sleep on Dixie Alley later in the fall and early winter as well. If the STJ can tap into the Gulf of Mexico sometime in November and pull that moisture into the Dixie states, there could be a chance at maybe a decent event or two down here as well.

 

[calvinkaskey]

Some of the hail to wind damage ratios in the eastern united states are very poor. Only 26 reports of large hail in New York, 36 in Pennsylvania, only 44 in Ohio, 39 in Wisconsin, and 18 in Michigan. States in the east that I am pretty sure are below average for number of tornadoes at this time of the year are N.C. with only 9, N.Y. with only 3, Mi 6, MD 2, OH 5, WI 16, VA 5, S.C. 7, W.V 2, N.J. 0, IN 15, KY 15, GA 14, FL 11, AL 22, AR 15, MS 21, LA 17

 

[Todd Lemery]

Wow. It seems like suddenly, chase season is dead. With fall conditions the last few days, it seems like the Northwoods are pretty much toast for the year. I'm still hoping for a couple of days this fall to head to the southern plains for one last gasp. I can't in recent memory recall a season up North where the isolated supercells were so hard to come by. The morning leftover crapvection we had this year also seemed to kill every good setup. The farmers have to be pleased with how the summer turned out though. I'm not giving up though, it only takes one good system!

 

[James Gustina]

It's still relatively early thankfully. Ridge doesn't look like it'll be breaking down anytime soon so god knows when we'll start even seeing digging troughs on the Plains again.