Quick final (?) weather update

Happy Korteloppet morning, everybody, and check out our podcast from yesterday.

A quick note on weather: all signs are still good.

Friday morning is cold, but it should be in the 20s by Korteloppet time and crest just above freezing—maybe as warm as 35—by 2 or 3 p.m. It will be breezy, as southwest winds peak later in the afternoon.

Tonight it is clear, calm and colder, down to around 15, and plenty of time below freezing to freeze the trail solid, from the top down and, since the snowpack will retain a lot of cold, from the bottom up. I would assume the Birkie will be grooming early to let the trail set up well overnight.

Then tomorrow, it starts out cool at race time, with the early waves going off around 20˚. But don’t overdress! The temperatures will warm during the race, up to freezing by about 11:00 and then continuing to warm into the 30s and maybe up to around 40. In the shade, the cold snow and shade should keep the snow frozen and fast, but in the sun, especially for later waves, on south-facing downhills and on the lake, it might get a bit slower and slushier. Good news on winds, though, which will remain light throughout the day, although any winds that do blow will be from the south or southwest.

As for the snow, the course may be slower than expected with the new snow, but I would assume it has been well-tilled and worked and should be solid. For the Birkie, I’d expect the section after OO to be quite transformed during the race today and to till up tonight with some colder powder below and ski quite fast.

(It should be noted that one model, the high-resolution NAM, keeps some low cloud cover in place on Saturday, with cooler temperatures because of this, but it is currently an outlier.)

“Okay everybody, let’s calm down”

This is what I posted when someone was freaking out that the Birkie might start at 35 degrees (slightly updated):

The snow pack is cold and it won’t be too windy. Except for some south-facing hills (almost always downhills) and maybe the lake and a couple of fields, ambient of temperatures of 33 degrees will not warm the snow as the cold snowpack will radiate out cold air to the surface. These are 2m air temperatures, meaning 2 meters above the surface.

The Korteloppet may transform the snow, but 12+ hours in the low 20s overnight will freeze it right up and there’s a lot of powder down there to till back together. But the model output statistics, which tend to do a better job with high and low temperatures, show it going up to near 40 on Friday, and then in the 12 to 14 range overnight, and I would not be surprised if those verified during the day on the warm end and overnight on the cold side if the surface winds decouple from upper level winds and there is even a couple hours of radiational cooling. Temperatures at 8 a.m. on Birkie Day may actually vary significantly across the course, but should even out by 10 or 11. The models are mostly in agreement that it should be down around 20. There are sort of two camps: one which is clear and calm and gets down into the teens and then up into the 30s, and another which keeps temperatures warmer overnight with some cloud cover, but the clouds keep it cooler on Saturday.

In either case, I would not expect most of the course to be anything but cold and frozen until about noon.

If you’re looking for information about recording yourself and sending it in for a podcast, you can find information at the bottom of this post.

Well, it snowed

Reports of 5″ new snow in Cable, and probably similar amounts up and down the trail.

This means that while they will be able to till this into the base, it probably won’t be as fast as it was looking before this latest round of snow went from 0 to 5 inches in the course of a couple of hours. And my soft, cold skis are certainly happy. But it should make perfect conditions even better. The Birkie crew will be packing the trail all week to compress and compact this new snow, the trail is close, so give them a wide berth.

And get excited. It’s fever time.

Dumping, but not for long

Screen Shot 2020-02-17 at 9.51.01 PMIf you look at a Birkie webcam screen grab right now you’d see it dumping snow. And it is! A heavier-than-expected band of snow set up across Northern Wisconsin today and what was looking like a dusting has turned into an inch, or maybe even two. It’s coming down starting in the upper 20s, and will finish a bit cooler and powderier, and temperatures fall tonight, plateau tomorrow, and then fall again tomorrow night (if the winds let up with fresh snow cover, -20 is not out of the question).

What does this mean? Probably not that much. This snow will be worked into the Birkie’s existing base by means of a lot of tilling, most likely, and will probably slightly slow conditions for the race. If you were on the edge between softer and harder skis, the softer skis may win the day, but the Birkie will probably do a lot of work to make sure that the base is solid by race day. And while it does look like Saturday will get above freezing, Friday may not as the models have backed away from temperatures cracking 30 until midday on Saturday, so except for south facing hills on the second half of the course, what is on the trail later this evening is probably what the race will be skied on.

Which is not bad. Because it may well be the best race conditions since 2010. Ski conditions and race conditions are not exactly the same thing. What I might like to ski on—some nice fresh powder clinging to the trees as I softly glide through the woods—is different than what I want to race on. For a race, I want a cold, hard-packed base, with a mixture of powder and older, transformed snow which will all freeze together to be fast and fun. And that looks like what we are going to get. No complaints from this skier!

Narrowing the goal posts

The Birkie is looking great.

I’ve said many times that the fewer times I post (and the less traffic that this site sees) the week before the race, the better the conditions. And this year, I’m kind of trying to come up with weather speculation posts, but there’s not much to speculate. The weather is going to be … nice.

Here’s a quick run down of the weather for the rest of Birkie Week. And remember, there is a very solid, partially-transformed, apparently amazing base. Race is definitely on. No meltdown. No blizzard.

Monday: Maybe a dusting of snow. Temperature up to around 30

Tuesday: High of 20, cloudy.

Wednesday: High of 10, sunny, lows around -10.

Thursday: High of 20

Friday: Highs in the mid-30s to around 40. Since the Korteloppet runs midday, the course may actually get a bit warm, especially for later-wave skiers and on south-facing hills. It actually could be a quite tricky wax day, since the surface might be warm and even slushy, with a lot of cold snow underneath. But it should be a lovely day for spectating in Hayward, and for skiing.

Saturday: More of the same. Most importantly, all of the models suggest that the temperatures overnight will drop at least down to about 20 degrees overnight, if not colder. That means the course will be able to take a groom from the day before, and freeze solid overnight. What will be interesting on Saturday is how it skis, especially in the second half. I’d expect the first half to be cold and not too transformed. But the second half, which will get mashed out in warmer weather on Friday might transform a lot and then get groomed and freeze up and be very fast with icier tracks. It might be very fun to ski, with some blazing downhills near the finish, at least before the sun gets too high. Then on Saturday, it looks to be 30s, dry and sunny. If there was ever a day to walk around Hayward with a t-shirt and a six-pack, this could be it. Maybe the perfect combination of skiing and sun. The sunblock concession will do quite well!

A couple of other notes:

The Birkie Trail is closed on Monday night for the rest of the week.

“But Ari, why would the Birkie do such a thing? It’s going to be super cold with a super-hard base and it’s not like we’re going to put ruts in the trail.”

True. Also true: there’s going to be a lot of traffic on the trail getting everything set up before race day. Do you want to meet a groomer at 25 mph on a blind corner? Probably not. And while some years in the past they have allowed skiing closer to race day, this race week closure seems pretty standard. So respect it! There’s always the possibility they read the forecast and postpone the closure a day or two, but unless that happens, ski somewhere else.

We have information about nearby ski trails here, and there are generally excellent conditions this year everywhere.

The Birkie is trying to keep people from littering, and by litter they mean goo packets. So if you have goo packets, throw them away at or near an aid station, or stuff them in your shirt or pants. Details here. They say they will assess a 15 minute penalty for littering, which is kind of harsh, but then again, the trail is probably covered with gel packets once the snow melts, and, ick. So be kind.

For this year’s Main Street (drunk) podcast, we want to hear from you! I can maybe interview 30 people as I drink New Glarus after the race, but you can interview any number of people, just on your phone! Then I can take all of this sound and stitch it into a podcast (or several) and drop them this summer into your podcast feed and you can listen to the Birkie in July (or whenever). So, if you have an iPhone, open the Voice Memo app and just hit the record button, then when you’re done, email the file to info@birkieguide.com. If the voice memo app doesn’t work on your phone, here’s another iPhone app which works. And if you have an Android, this app works. This is literally how KIKKAN RANDALL recorded a podcast this fall.

Speaking of, KIKKAN is in town and at several events. You know, the same person who came on ye olde podcast this past fall. This is the unofficial guide, though, check that out in the official guide.

240 hours to go

How do I know it’s 240 hours? 240 hours is when the weather models come in with data for race morning. And so far, all systems are go.

There’s a chance of some light snow between now and race day, but it doesn’t look like more than an inch or two. Also a chance of a slight thaw, but not more than 35 or 36 during the day. No washout, no meltdown, no blizzard. Just, basically, more of the same.

For race morning, and this is 10 days out and likely to change, the models advertise temperatures around 20 with light winds, rising towards 30 during the race. Cold enough to be fast, but not so cold as you need double wind briefs.

And by the way, catch up on the BirkieGuide Podcast if you haven’t already!

Getting in clown range

Weather nerds sometimes speak of “clown range” for weather models. Clown range implies that, beyond a certain time frame, the weather models are about as good as a clown predicting the weather, usually beyond about seven days. But for very wide-scale trends, there are ways to read tea leaves to discern large-scale trends: wet vs dry and warm vs cold. Will it be 0 or 45 on race day? Who knows. But even a month out, we can say whether there is a greater likelihood that it will be warmer or colder than normal: we were worried in early February of 2017 because the models painted a picture of very warm weather four weeks out and look where that led.

So far? So good. The next two weeks look warm-ish (but not snow-melting-warm) and then cold-ish. And beyond that? Normal-ish. I’ll take normal-ish with a good base in place. Normal-ish doesn’t melt two feet of snow. And normal-ish make for some of my favorite Birkies, like 2009 and 2010: cold to start, warm and sunny by afternoon.

But I’ll take anything with 50k of snow on the ground to Main Street, frankly.


One month to go (or so)

So, time to fire up the old Weather Speculation machine!

Long story short: I think we’re in decent shape.

The next two weeks are warm. On the long-range maps, they show up as anomalously warm by 2 or more standard deviations. But anomalous warmth can be either good warmth (not too cold with some frozen precip to build the base) or bad warm (high temperatures or rain which eats the snow). And the next couple of weeks look like good warm.

For instance, the normal high in Hayward today is 22, with the normal low of -1. The next couple of days will sit right around 32 with some light snow or wintry mix. Not enough to add to the base, but nothing that will remove it either, and with last week’s storm, the base is in pretty good shape. For the rest of the week, the temperature will remain between 20 and 35, but it will stay dry. So is this quite warm? Sure, but it won’t do anything to the base. I’d much rather have this type of weather than temperatures of -10 followed by a rain storm.

This pattern may continue clear into early February, before it finally cools down. Not much new snow, but nothing that appears to be a major meltdown. I’d actually rather see this followed by a cool down closer to the Birkie than the other way around. Weather is cyclical, and a few warmer weeks are often followed by a few colder weeks. If we can survive the warm and get into a colder cycle come Birkie, as the models suggest, we’re in good shape.

Obviously, a ton can change between now and race day (and a lot will). And one of the best things on our side this year is a reasonably early race: February 22 rather than the 27th or 28th. If we assume that in any given year, the chance of the Birkie happening is 90% (since it’s been canceled about once a decade in its history) I would put the chances of the race happening, given current conditions, higher than that, in the neighborhood of 95%.

Ski on!