How Far Will You Travel for a Slight Risk?

[Bob Hartig]

Just as a matter of curiosity: How far are you willing to travel for a slight-risk day, and what criteria do you go by?

I ask because chasers come from across a broad geographic area, a wide spectrum of forecasting expertise, and a diverse background of financial and personal circumstances, all of which can factor into when and where one will chase.

 

[John Farley]

For me, that depends on a couple things. I don't like to go more than a 4-hour or so drive from home on a single-day chase, so a major factor is whether it appears to be just one slight-risk day or several in the same general region. I generally go on longer chases when there appear to be two or three days with decent potential in the same general region. Of course it isn't just a matter of slight risk vs. some higher level but also the potential for supercells and tornadoes vs. other modes of severe (probably pretty obvious). And of course it depends on schedule. But in general, assuming I don't have schedule conflicts, I will go a lot further for a decent multi-day setup than for a one-day setup with a comparable potential.

 

[Timothy Finn]

I tend to not go by the risk assessment, but rather I let my forecast guide me. The setup is what attracts me, and if it looks to be a good setup, I'll go the distance.

I know that is somewhat vague, but I'm learning this is a very fluid situation that requires adaptability, and as such, I have to weigh every variable I can to make a decision of how far to travel.

Tim

 

[Jeff Duda]

I pretty much limit myself to out-and-back one-day chases, as I don't want to deal with getting hotels (not like I would save any money from staying overnight and driving home the next morning anyway). This usually keeps me within about 6 or 7 hours of "home", but I find myself pushing that boundary farther out each year. And that usually applies no matter what the risk level. I've driven 7-8 hours for both slight risks and high risks (and busted in both scenarios, too).

Really, the decision of whether or not to chase comes down to a cost-benefit analysis. I look at how much time, money, and effort it would cost me to chase versus how much enjoyment I would get out of it (enjoyment is my only dimension since I don't make any attempts to sell video or photos) and how much time and money I have at the time. Sometimes when I'm stressed and busy, I'll refuse to chase a slight that's three hours away. Other times when I'm bored or my SDS is worse, I'll drive six hours for a 2% tornado risk.

 

[Skip Talbot]

Some of the most photogenic tornadoes and best chase days occur on the low end slight risk days. Campo for example, started out as a low end slight with 5% tornado probs and was downgraded to a see text with a 2% before the tornadoes occurred. You can't chase them all unless you have no obligations and unlimited wealth, but I usually try to pick a handful of 2 and 5% days in the hope of winning the lottery. If I can get a string of 3-4 in a row, playing a couple upslope days, waiting for a trough to eject in the plains, and then chasing it home, that's ideal. So the answer to the original question is, anywhere in the plains from New Mexico to North Dakota (I've chased 5% setups in both), I just can't do it all the time.

 

[Dan Robinson]

My chasing has developed into two distinct subsets, Midwest chasing and Plains chasing. I've reached the point (albeit through much failure and dues-paying) where my criteria to chase in the Midwest is parameter-based irrespective of SPC outlook, and as such the presence/absence of a slight risk tends to be incidental. Most of my Midwest chases do end up being on days that turn out to be slight risks or greater. In the Midwest, 'magic' can happen throughout the outlook scale, particularly with warm fronts and cold-core days - so as long as those ingredients are present on an even subtle level, I will go 3 hours (give or take an hour) regardless of SPC outlook level (providing I can comfortably afford the fuel expense). Available leisure funds and work schedule are the only hindering influences that would cause me to not chase with those parameters present.

For the Plains, my criteria are much more stringent - again, more parameter-based than outlook based, though nearly all of my Plains 'trip anchor' days end up being moderates or highs. For the Plains I want big instability, southwesterly 40-50 knots or more at 500mb, and large looping hodos below 500mb - days which usually end up as at least moderates. The Plains can and does get the subtle-parameter 'magic' slight risk days just like the Midwest, but finances prevent me from getting out for those (like it does for most of us, I can imagine).

If a slight risk caliber event or two is tacked onto either end of a larger high-probability event that I'm already in the Plains chasing, I'll stay out for those extra days before or after - I just wouldn't make a multi-day trip for the Campo, LaCrosse or Rago type day. Yes, the cost of that methodology is missing those events, but the price for capturing them is high - one must be out for a large number of the subtle-parameter days, which is cost prohibitive unless you're simply in fixed-length vacation mode.

If I lived in the Plains, I'd be out for the same criteria days there as I do here in the Midwest now. The subtle days happen both here and there - the difference is that the Midwest's slight-and-lower days usually have chaser numbers in the single digits!

 

[Rob H]

I live in Minnesota, and I'll chase a slight risk in the panhandle or in Colorado, if something like a Denver Cyclone or the DCVZ is in play. The "garbage" storms on these setups still seem to produce amazing structure, good hail, good lightning, and isolated storms. Some of my best chases have been on days that weren't supposed to be the big show. I also have personal "favorite scenarios" that for whatever reason really click well in my mind. I'll chase a slight risk that I understand intimately and like over a moderate risk that I don't understand or like any day of the week. Ultimately, the SPC risk outlooks serve as either a wake up call to pay attention to a day I might have missed, or to justify my forecast.

The only thing I've always said "no" to was Dixie Alley outbreaks regardless of risk outlook. With a kid on the way, I can't be picky about setups next year, so I'll probably see some of you down in Mississippi in 2013

 

[MClarkson]

Well there is lots of other factors going on... but if I was looking for tornadic storms only and I was looking only at SPC convective outlooks, I don't think I would go very far, for a slight risk. I'm usually not impressed by tornado potential from slight risks, although there are exceptions, and my recent chase history certainly would be a factor as well. After a couple years living in my new home of Portland, I'd probably be willing to cross half the state for the slightest slight risk

 

[David Hoadley]

My northern Virginia perspective normally requires at least two consecutive days of severe to warrant a 3 day, 3,000 mile round-trip. I look for a surface low with backed winds under a S-SW-W flow at 500mb for significant vertical shear. A curving moist tongue, wrapping around and NE of the low, also confirms the strength and persistence of that flow. If this consistently appears over several days, all the better.


If no backing winds but mainly northerly flow east of the low, I then look more closely for compensating diffluence at 500mb, especially around the toe of a deep trough --and if that trough is inclined to a negative tilt. I also look for significant vertical shear. Generally, if that angle (surface to 500mb) is 25 degrees or greater, I am interested. Anything less than that is inclined to meridional flow and may line out early.


My goal is always to start a new chase day, close to or within that morning’s SPC risk area, so I can spend more time in the motel, gathering data and forecasting. I still use my ancient surface analysis technique, looking for “pattern recognition” in morning surface maps that indicates where afternoon tornadoes may be. It is about 70% accurate in a comparable-to-SPC watch area (sometimes smaller) and with 8-9 hours lead time. But I am not hide-bound to it, and remain flexible to respond to changing reality.


I also look at whether the trough or cutoff upper low is in a weakening stage, rather than strengthening. If a close-call forecast (could go either way), then if the overall system is weakening, I’ll often let it go.


I always consider how photogenic the tornadoes may be, since I don’t wish to spend the big bucks and long hours, driving out and back just for bragging rights on a few wimpy spin-ups. So, the likely quality of photography plays in this decision.


The first day’s drive usually ends in Terre Haute, where the next morning’s forecast for the plains is checked one last time. If it is a typically difficult, early spring pattern and significant parameters don't look just right, I may turn around and go home (only a 2 day penalty). Almost every time I have done that, it was the right decision.


- - - David Hoadley (Falls Church, VA --inside the beltway around Washington, D.C.)

 

[Brett Roberts]

The most distant chase I've done, Bowdle, was a SLGT and about 800 miles from home. As others have already covered, the categorical risk doesn't play a particularly large role in determining what I'm willing to sacrifice (money/time/energy) for a chase. Another interesting consideration is that major, widespread tornado outbreaks that warrant a HIGH risk seem less common in the portions of the Plains most distant from me (Dakotas, E WY, E MT), and relatively more common in nearby states like TX/OK/KS. I don't really mess with Midwest and Southeast events usually.

 

[Adam Lucio]

Interesting question. As many have stated it depends on logistical factors more than anything. The farthest I have driven for a low end slight is Chicago to North Dakota and most recently the Texas panhandle. 10 hatched seem to be my best tornado days though, and they fall into the SLGT risk category. I will go where I need to go if I think I have a chance of seeing something awesome and all the logistics fall into place.

 

[Sean Ramsey]

It depends on the time of year for me. I'm much more likely to chase 6+ hours away on 2%-5% day at the very beginning of a season (late Feb-Mar) because I haven't chased in forever, and towards the end of the season (late Jun-Jul) because I know opportunities are limited afterwards. During the season I think I'm more likely to chase very slight risk days closer to home and save the long trips for days with higher risks.

 

[Shane Adams]

I'll go as far as my wallet can take me. I don't look at the categorical risk so much as the type storms I expect to see. A lot of people get caught up in "it's only a slight" and scoff at certain days, when the reality is, slight risk days hold as much potential as high risk days...you just have to nail the forecast. If I believe there will be one single supercell that could produce tornadoes, I'll go as far as I am financially able. An example would be May 16, 2000. This was supposed to be the "day before the day" (Brady, NE was the 17th) and a big part of the reason I even bothered was to set ourselves up for the next day. We ended up on a single storm in SE Wyoming, all by itself, which went on to produce a pair of tornadoes, one of which remains one of my all-time most photogenic. We didn't need an outbreak or a moderate risk with multiple storms. We just needed one storm to be amazing, and it was.

A lot of newer chasers like to boast on their forecast ability and bash the SPC (claiming not to be influenced by them), but when it comes down to crunch time, you just don't see the confidence in a slight risk the way you would a moderate or high. I think this is indicative of two things. First, that many people don't understand what categorical outlooks really mean, and secondly, there's a lot of armchair folks out there patting themselves on the back who don't have the confidence to test their forecasts.

Some of my best tornadoes have come on slight days that featured just one or two great storms. A few examples are May 12, 2004 and May 22, 2007. I usually don't have to drive too far because anything financially reachable (and worth chasing) is usually within 4-6 hours of home. But you will never see me sitting on the couch because I simply didn't think it was worth the drive; there's either a flaw in the setup (to my eyes) or I simply can't afford the trip. I'm never that person who says, after missing a great event, "Oh man, I should've chased."

An example of this working in the opposite direction is this past weekend; I spent days pouring over whether Friday was worth the shot or not. The main issue I was dealing with was, we didn't have quite enough money to make the trip comfortably. To be able to make it to my target on time, we needed to leave early. Friday was payday, but by the time I got my check deposited and everything else in order, it would turn into a game of racing the clock and probably missing out. Plus, with a Saturday chase quite likely, we simply couldn't afford both. Had we had an extra $100 in the bank that week, Friday would've been a no-brainer. As it was, I "chose" Sat (was really financially forced to take Sat) and we missed a few tornadoes on Friday. However, Sat rewarded us with a surprise severe storm which we got exclusive video of, as well as our first ENG video sale. So in the end, despite missing tornadoes on Friday because we couldn't afford to chase, our Sat chase ended up free. Strange how it works out sometimes

 

[Jesse Risley]

It's a risk vs. reward scenario for me, and it has nothing to do with the categorical probabilities of an SPC forecast. I always make my own forecast before chasing, weighing the potential storm inhibiting factors (e.g., meager instability, shear displaced from best thermodynamics, storm evolution, etc.) with the most optimal factors for SVR storms and/or tornadogenesis.

I live in Illinois, so the aforementioned cost vs. benefit analysis is an important decision when deciding whether or not to travel a respectable distance to chase. I've probably seen more tornadoes on slight risk days than on the two higher risk days (MOD and HIGH), being the least successful on high risk events. If I have the time to spare and the setup looks to be worth the financial cost, then I have been willing to travel anywhere within the alley to be in the best position for an intercept, without regards to the categorical risk assigned by the SPC to that particular areal region.

 

[Steven Williams]

When you are on a stormcation from overseas you chase just about everything. Even go to Montana for a slight risk!