Birkie Prognostication

Screen Shot 2017-02-20 at 7.54.51 AMWe’re not going to the American Birkebeiner this year, which means that we’re free to prognosticate from home without any big chance of having to eat our words. We won’t be offering an official wax recommendation this year because the weather is comically chaotic. But we’re happy to offer an interpretation of the situation, and some thoughts on preparation.

With five days to go before the race, circumstances are mighty uncertain. The upper Midwest has started a serious thaw, with the next opportunity for an overnight freeze coming Wednesday night. A few days ago this thaw looked like a relatively short-lived event, but the forecast has gotten considerably more grim. Right now there are serious questions about whether the base will hold-up, and chances of finishing the event south of OO are diminishing rapidly.

There’s not much any of us can do about the weather, and the best thing that anxious skier can do is look ahead and plan for contingencies. Right now there are a couple of scenarios, and everything seems to hinge on a storm system that will be coming through on Friday. As usual, with forecasts this far out, there is some divergence in the modeling of this storm, with scenarios all over the map. The most favorable forecast is from the European model, which seems to promise the possibility of a foot of snow (that has been backed off as of Monday morning). Less optimistic models suggest 3-5 inches, and everybody likes the chance of pretty considerable wind.

What seems like a solid bet is cooling temperatures beginning on Thursday. While temps will still crest the freezing point after a mild freeze Wednesday night, the warm air will be on its way out, and more seasonable cold will arrive in time to stabilize the base (or what’s left of it). The chance of arriving snow is a real complication for race organizers, who will want to capture and pack the snowfall, but will also be concerned about the base, which is likely to be heavily saturated and still in the process of refreezing when the snow arrives.

Last year the organizers closed the course because of forecasted warmth, in what appeared to me to be an hysterical response. This year they have absolutely no choice. The course will have to be closed, and I would anticipate that it will be closed right up to race time. With the late arrival of snow, the waxers will have a relatively low stress week since there will be simply no opportunity to test. Oh, they’ll all be out there Friday in the wind and the snow, trying to learn something. And they’ll make decisions based on what they learn. Some will get it right, and some will get it wrong, and overall the value of local knowledge will be on the high side at an event where local knowledge is already at an absolute premium.

Screen Shot 2017-02-20 at 7.56.51 AMSo – what about skis and wax? Anything useful to contribute there?

Most years it seems to me that Birkie waxing is defined by a heavily refrigerated snowpack. In “standard” Birkie conditions we expect to hear about people on straight paraffin (no per-fluorinated top-coats) showing up with awesome skis, and some of the fancier and more expensive wax jobs turning out to be a big disappointment. This year, the lead-up to the race will guarantee that the snowpack is not deep and refrigerated. If most Birkie scenarios push the thinking toward the cold end of the forecast, then this year I would suggest that circumstances are pushing in the other direction.

We will need to keep an eye on things as the forecast develops. A long period of solid freezing prior to the onset of snow might make things run fairly true to the forecast temps. A foot of snow on top of a solidly frozen ice base is likely to be a deep slugfest, but a fairly dry affair. However, three inches of snow arriving just as the freeze sets in could be very, very interesting and challenging, and the timing of grooming and course preparation could be critical in determining how much moisture migrates into the new snowpack, and whether the surface packs or breaks.

Here’s what I would consider setting up for the race:

Soft/Cold Skis – Most Birkie skiers have a pair of skis well suited to soft and cold conditions. I would plan to wax these with a fairly standard “blue range” build-up on the high end of the fluoro content spectrum. Consider a Red Creek LF hard base (which has won in new snow all year for us), followed by Red Creek HF Green Mix, Star VF6, or Vauhti UF Blue. For a powder I would look at Vauhti LDR or Star F25 – both have been a really good bet in the range. For top-coat the most reliable products have been LDR liquid and Star FS6 block. These top-coats are where the folks with a chance to test will have the biggest chance to make a difference.

Stiff/Cold Ski – If you have something to deal with packing conditions, I’d recommend setting it up for higher moisture. The only scenario I can envision where the surface is hard is either one where no new snow materialized, or where the new snow falls onto a saturated base and wicks moisture toward the surface creating a frozen glaze. In those circumstances I would go with Star VF4 for paraffin, and I wouldn’t even worry about testing anything else. It’s just very, very safe when moisture comes up, even with temps in the teens. I would stay in the same range on fluoro products – F25 or LDR, and maybe more of a nudge toward liquids – LDR liquid or Star XF6.

Soft/Warm Ski – There is a chance that relatively little snow falls, and it all gets tilled together with the dirty, wet ice below. In that case I would also be inclined to go with VF4 paraffin, but probably over a “black” base. Last year we saw astonishing speed from Toko LF Moly, which might not even exist anymore. I would also have confidence in Rex LF Black. For fluoro powders in that scenario you may need to be looking at something “wetter” mixed in to deal with the ice and old snow in the mix. I’m thinking of a Star F30/F15 mix, or Vauhti Wet (9.1) mixed with the old hfC15 (otherwise known as C11). In this case I would once again bet on liquids being the best, and would continue to have confidence in LDR, but maybe the XF4 from Star to deal with older and dirtier snow in the mix.