State of the Chase Season: 2015 Edition

[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.