Truth in snow reporting

[polski]

Via Eric Wilbur on Boston.com I learned today of a preliminary study by two Dartmouth researchers on truthfulness in ski resorts' snow reporting. The researchers studied resorts throughout the U.S. and Canada and found significant exaggeration, though a "technology shock" early this year - introduction of an iPhone app making it easy for skiers to post their own condition reports in real time - may be putting an end to that.

I'm still reading through the 32-page study with a critical eye on its methodology, particularly re the timing and measurement of snowfall by resorts and government agencies. It appears the conclusion is based mainly on a "weekend effect" in which resorts reported 23% more snowfall on Saturdays and Sundays than on weekdays, when there was no such statistically significant effect in government snowfall total data. (The authors found that ski areas reported more snow than government observations on all days of the week, but acknowledge that that could be because of the location of ski areas -- presumably sited in locations most favorable for snow -- vs government weather observation stations.)

The researchers, Jonathan Zinman and Eric Zitzewitz, say the weekend effect was larger early in the season and in January and March, while being essentially zero during Christmas week and April/May. They conclude: "These results are consistent with skier decisions being more sensitive to snowfall early in the season, with purchase decisions being made in advance during holiday periods, and with skiers being less sensitive to new snow during the 'spring conditions' portion of the season."

The study also found "Weekend effects in snow reporting are larger for resorts with more expert terrain and those within driving distance of population centers. This is consistent with expert skiers valuing fresh snow more highly and with resorts near cities having more potential to attract weekend skiers."

Snow report exaggeration reportedly fell sharply since January, when Skireport.com rolled out an iPhone app for skiers to post their own reports. "But first-hand reports spike only at resorts with adequate coverage from AT&T's data network," Zinman and Zitzewitz wrote, "and these covered resorts experience a disproportionate post-launch drop in exaggeration."

Lots to chew over here.

 

[riverc0il]

Nothing we did not know already. Well, I take that back. I was surprised to learn that ski areas (on average, though I suspect early openers may still be outliers) are accurate early and late season.

 

[drjeff]

Personally I believe the early season accurracy of the snow conditions report - especially in the East Where your talking machine groomed snow as your primary surface (and Riv I agree with the commentary you made last year about "actual skier" packed powder vs. "machine groomed" packed powder NOT BEING EQUIVALENTS). The biggest issue I have with early season accuracy ssues is the standard hyper inflated trail counts were 1 continuous run down the mountain made up of portions of say 5 trails = 5 trails open That's where the BS factor comes in and hopefully where mobile smartphones will embaress some areas into honesty in reporting

 

[polski]

A report by WCAX TV in Burlington, including rebuttal by Tommy Horrocks of Killington and a spokesman for the Vt Ski Areas Assn.

In reading the Dartmouth report I thought it was an interesting attempt to quantify the issue, though that's difficult to do, for some reasons explained in the study and others I can think of. For example, the govt agency snowfall totals all would be single precise figures, while ski areas often report ranges from different elevations. In any event, the "weekend effect" approach seemed about as clean a way as possible to draw the conclusion the authors did.

To me the big takeaway is how ease of real-time first-hand skier reporting via social media may make the resorts' snow reports more honest. Better living through technology ...

 

[polski]

p.s. Riv, the report did control for early-season effects, including the fact that sometimes ski areas only are open on weekends early in the season (in fact that was mostly true for Killington during its first week or two of operation in mid-Nov). In any event the authors did find a "weekend effect" in early season, less so during Christmas (when ostensibly snow reports made less of a difference in skier decisionmaking because so many had booked trips in advance) and in spring (when new snow is less of a factor in decisionmaking).

One nit I'd pick is with the paper's statement that "A skier wishing to ski on fresh snow can use these snow reports to help decide whether and where to ski on a particular day." The paper acknowledges that with most ski areas privately held, it's basically impossible to get data on skier visits, especially as granular (x resort x day of week) as it would need to be for this analysis. I'd surmise the weekend warrior doesn't typically make a go/no-go decision ("whether") based on a morning's snow reports, though that's possible in some cases where forecast precip type was uncertain. I definitely can see those reports affecting *where* skiers end up, though, for resorts within day-trip range anyway. At least before smart phones + social media made real-time consumer reporting much easier.

 

[riverc0il]

I disagree that social media, wifi, and live reporting will make resorts more honest. I have been posting trip reports to the internet for almost 10 years now (wow). AZ and other forums came online around that time too. Web sites like FTO and SkiVT-l pre-date even my most rudimentary attempts at a trip reports web site. Online trip reporting is nothing new and the Web 2.0 social media and social networks are not going to change official snow reporting for the better. I have noticed no change in the past 10 years.

The reason is simple. Accuracy in snow reporting is difficult because there are so many variables. Where do you measure? If you are reporting a range, where do you pick your ranges? Do you measure total snow fall before or after the wind has picked most of the new snow off the trails?

And how many people doing online trip reporting are bringing rulers to the mountain? I have never ever once seen someone who bought a lift ticket break out a ruler at the mountain and take multiple measurements to verify accuracy. Most of us just eye ball it using the official number as a benchmark. So personal trip reporting should usually be looked at just as critically as official reporting because people are not using rulers themselves and likely have an error margin of +/- 10-20% I would guess.

Plus, Joe Average skier who is the target market of ski resorts is much less likely to be involved in social networking that provides a wide range of opinion on how good the snow reporting is. These folks don't even buy their ticket and/or get to the mountain until the new snow is tracked out any ways. Joe Average skier is not a good powder skier and is just fine not getting first tracks. Simply put... the customers that provide the ski resorts with the most profit either don't care or can't be bothered about the accuracy. It is a limited number of crazy powder hounds that will most likely blow the whistle on even one or two inches inaccuracy.... and because of the powder hound status, non-powder hounds take our reports with a grain of salt any ways.

 

[skiadikt]

though snow total amounts can & have been exaggerated, to me the biggie is surface conditions & weather. the deception is in the omission and not telling the whole story.

the catch all phrase is "machine groomed packed powder". that's virtually meaningless as it can encompass a wide variety of surface conditions from nice corduroy to death cookies & ice. sometimes you get loose granular in the report. almost never frozen granular.

and they'll never tell you it's raining. in the old daze at hunter, when i called the sno phone on a rainy day, it was busy. couldn't get through all day. swore they just took the thing off the hook. at k, remember arriving friday nights in a monsoon and the report would say we expect to have x lifts & trails open this weekend and we received 18" of snow this week. yeah that was monday. that snow's been washed away already. no mention of the "r" word. how 'bout arriving at the mtn to find no or maybe one lift running. more often than not, no mention in the report. maybe "some" lifts might go hold ...

however in recent times, i am seeing better reportage from the ski areas themselves as the internet w/web cams, smart phones etc has forced ski areas to be at least more forthcoming. we see it at jay & mrg. even today's k report:

"With some non-winter moisture heading our way, we're going to keep the snow cats off the hill so the terrain will be au natural for Thursday. So break out the Gore Tex and enjoy some soft snow conditions."

that wouldn't have happened 3-5 years ago ...

 

[billski]

Nothing we did not know already. Well, I take that back. I was surprised to learn that ski areas (on average, though I suspect early openers may still be outliers) are accurate early and late season.

I did not know these data either, but in some ways the early/late accuracy does not surprise me. It's always difficult to persuade people to hit the mountains when there is no snow in their backyard. It always drove me crazy when trying to organize trips. Just demonstrating something is up there is far more important at that point than how much or what condition its in.

 

[billski]

I disagree that social media, wifi, and live reporting will make resorts more honest.

The largest change came when data could be provided on a daily basis. Some of us remember when the best information came from first-hand reports and expensive toll-phone-calls, with information that was at least one week old. People also didn't have the mobility they have today. How many people in your office or social group can you go physically walk up to and discuss their last trip? That's the way we had it; very limited communications with stale information. Talk about an adventure. You'd usually arrive with not a clue about weather conditions.

We are actually pretty spoiled today. I prefer to aggregate information from several resorts in the area, and other nearby sources like webcams to "see for myself" what the general trends are. I absolutely, positively NEVER take a snow report as a guarantee of conditions. Never have, never will.

Social media - everyone has an axe to grind. What is "epic:" to you may not be "epic" to me, and that's OK.

 

[ta&idaho]

Ski resorts should post measurements from the same stake every day. Let the facts speak for themselves. I don't know much about the Mt Mansfield stake, but I'm impressed by the data it generates. I also love the stake cam that my home mountain provides: http://www.brundage.com/the-mountain/live-web-cams/ (fyi: the stake is located near the top of the main quad chair, in an easily accessible location).

Conditions have more variables out here, but providing one consistent (and highly relevant) metric would be a good start.

 

[speden]

Sometimes I feel like ski resorts intentionally place their webcams in spots where you can't get that good of a view of conditions. Or the picture quality is so low, you can't tell much about the conditions. Then the constant unexplained outages of some webcams seems suspicious. I'm probably just cynical. Maybe it's just a case of they put them on the base lodges blocked by roof overhangs because that's the easiest place to install them.

I usually deduct a few inches from ski resorts snow reports because I assume they are exaggerating them. I'm surprised there are periods where they do not exaggerate them.

 

[frozencorn]

Social media is indeed an impact because of how mobile it now is. It's one thing to write a trip report online when you get home, something else entirely if you're on your way to the mountain, and there's a Twitter feed from other skiers and riders telling you not to bother. The mobility of Twitter and facebook means that day-trip skiers can literally choose where they're going to go 2/3 of the way through the drive.

 

[ski_resort_observer]

After reading the report with this study I personally have concluded it's basically a joke. The researchers compared the snow totals reported by resorts compared to snow totals reported by the nearest NWS station. For us here in the MRV that's Berlin which is between Barre and Montpelier 25 miles away.

I think everyone in the resort industry knows the reporting system is not perfect. Most have stakes around their mountain and report what they show. Anyone who is familiar with mountain weather knows the snow levels can vary depending on where your at. IMHO depending on people's first had reports by phone is going to be as reliable as a screen door on a submarine. I know I'm a lone wolf here but I believe most resorts report accurately what their particular snow stakes show first thing in the morning.

 

[ta&idaho]

After reading the report with this study I personally have concluded it's basically a joke. The researchers compared the snow totals reported by resorts compared to snow totals reported by the nearest NWS station. For us here in the MRV that's Berlin which is between Barre and Montpelier 25 miles away.

The study's most shocking conclusions do not depend on a comparison between resort-reported snow totals and government-reported snow totals. Rather, they observed significant increases in snow reporting on weekend mornings, a pattern that was not replicated in government reporting (because actual snowfall obviously does not correlate with the day of the week). How do you explain a statistically significant surge in reported snowfall on weekends? Does Ullr commute to the MRV every weekend?

 

[ta&idaho]

Of course, these guys (Zinman, Zitzewitz) are obviously total hacks whose stastistical chops (and committment to objectivity) probably pale in comparison to Tom Horrocks.

 

[catskills]

You ever notice that centimeters look a lot like inches on a ruler. One inch of snow can look a lot like 3 inches of snow if you read the wrong side of the ruler. Its an easy mistake.

 

[chrisrunsi]

what kind of ruler is that? I'm pretty sure most rulers are divided into 1/8th of an inch not 1/10th.

 

[catskills]

what kind of ruler is that? I'm pretty sure most rulers are divided into 1/8th of an inch not 1/10th.

Its a marketing ruler of course.

 

[speden]

The study seems incomplete. To get the full picture, they should have determined if exaggerated snowfall reporting actually makes casual skiers more likely to pick one resort over another. Such as, "Honey, Killington got 10 inches of snow, but Sugarbush only only got 8. Let's go to Killington!"

 

[abc]

Just because the bullet missed the intended victim doesn't make the murderer innocent. Actually, it make the guilty look even more stupid, going through all the hassle of lies for no return.