No lake? No lake. (47% chance of cancelation)

The lake is out.

The lake is a flowage: a dam across a river. If there’s a lot of melt and rain, the lake flows. If the lake flows, the ice becomes unstable, and you don’t exactly want to ski across it. So that has happened.

image1 (1)

This is Wheeler Road down by Duffy’s Field, we think.

Reports from the rest of the trail, at least south of OO, don’t sound so hot, either. Here’s my best guess as to what is going to happen, assuming the north end of the trail is at least mostly intact:

  • The Korteloppet will run from OO to Cable (or Cable to OO, depending on which direction makes the most sense).
  • The Birkie will run from Cable as far south on the trail as is possible, which will likely depend on how much snow (if any) falls on Friday. The latest model runs are all putting the Birkie right on the edge of the storm, so that will be a wait-and-see.

So the news today is … not good. If the storm comes north and drops enough snow, we might do fine. If not, the best we can hope for is a 25k Birkie to OO, much like 2007. In 2007, the storm hit on Saturday night. This year, it comes a day-and-a-half earlier. We’ll keep an eye out on it.

It’s the US vs the World (37% chance of cancelation)

Twice a day, we get three different models at the same time. At noon today, the Canadian and European models looked juicy for the end of the week: snow and cold for the Birkie. The American model? Not so great, again. It is cold for Saturday (and Friday, for that matter), but suppresses the low far south, far enough that the Birkie would see little more than flurries.

The latest from the trail makes me wonder if there’s much of a chance of keeping the snow through the race on much of the trail: two inches has already been lost with four warm days to go. So I’ve upped the cancelation probability to 37% (there’s a formula for this, below), but there’s still a decent chance of having a race.

How do I calculate these guesses? First, I estimate the chance that snow will come and save us. That is calculated by taking the proportion of the models giving us enough snow by Friday evening for a race and dividing it by the model pessimism adjustment rate (generally, 2). So if two of three models give us snow, I give a 33% chance that the snow will save us. Then I take the probability that the whole course will have snow and that just the north end will. Add it all together, subtract from 100, and get a cancelation percent. My guesses right now:

  • Probability of snow: 33%
  • Probability of part of the trail surviving: 30%
  • Probability of the whole trail surviving: 15%
  • Probability of cancelation: 37%

Two out of four (30%)

The overnight model runs are in:

The Euro looks great.

The Canadian looks great.

The American model looks … well, the most recent version brought a bit of snow in, while the midnight run was dry. So maybe that’s the right direction? It at least looks like there will be enough cold air in place for the race that whatever snow is left will be frozen solid. But it would be nice to have something on top.

Waiting … (30% chance of cancelation)

In recent posts I’ve used a football metaphor regarding the chance of a snowstorm saving our behinds for the Birkie. Since it’s 50 in Hayward, here comes a baseball metaphor:

It’s the bottom of the 9th, two out, runner on second, down a run. If we get a double or better (6″ or more) from the storm, the race will be great. A single (3-5″) may be fine, depending on how much base is left, but the runner could get thrown out at the plate. Any kind of out? We’re probably sunk.

Right now, we’re hitting about .500. The most recent models, to go back to football, have been shading towards a miss wide-right, putting snow down in Madison and Chicago but not on the Birkie Trail. But last night the models were missing wide-left, with rain on the Birkie Trail and snow up in the Arrowhead. The weather in Hayward today was warm but dry: so the base probably did okay. But there’s a lot of weather to come.

Some people have emailed me asking about weather models and where I get them, so here you go. For the GFS and CMC, poke around TropicalTidbits and PivotalWeather; you can also view model output at wxweb and the Bufkit Warehouse. The ECMWF is proprietary and you have to pay to access it, and we don’t have enough money for that yet (support our advertisers!) but you can view output from the Norwegian Meteorological Service (long story as to why, and as to why I know) here.

The trend is our … friend? (Cancelation: 30%)

Quick late evening post. The GFS and CMC model runs have come in (I really should post a glossary!) and both are pretty direct hits on Birkieland. The GFS is kind of perfect, it starts snow on Thursday evening and drops nearly two feet by Saturday morning. The Canadian is a bit later and a bit lighter, but still puts down nearly a foot by Birkie o’clock.

Based on this, and how confident Ben Popp is of the base in our podcast, I’m lowering the proprietary-calculation cancelation number to 30%.

(And wouldn’t it be odd if, after stressing out for weeks about the snow, we skied the Birkie on a foot of fresh powder in 10˚ temperatures with whipping winds?)

Screen Shot 2017-02-17 at 11.55.21 PM

Screen Shot 2017-02-17 at 11.55.47 PM

Podcast Episode 7: Ben Popp Updates

The latest episode of the Podcast is dropping (well, uploading) as we speak (especially if I upload them to the right directory). We talk with Ben Popp, the Birkie executive director, about the current status of the course, the chances of a good race, and preparations and contingencies. He’s realistic but optimistic: the base is solid and helped by rain which solidified it in January and earlier this month. He says there’s a 75% chance we survive the meltdown.

(Model update: the latest US model was very bad, but the latest European model very good. It’s wait and see at this point.)

55˚. 36% chance of cancellation

The forecast high in Hayward today was 47˚.

Right now, it’s 55˚.

This is real bad. It’s 55 and sunny, which is better than 55 and rain, but still baking away at the base. The hope was that fog or low clouds would mitigate the melt somewhat. That looks unlikely.

On the other hand, the European model prints out a direct hit for the Birkie next Thursday and Friday with 12-18 inches of snow falling, starting Thursday night. We’re now banking on that. Here’s my best guess at what may happen next week:

  • 6% chance the race is held on the current base
  • 18% chance the race is held on the current base, but is shortened to or turned back at OO
  • 40% chance the race is held based on new snowfall
  • 36% chance the race is canceled due to lack of snow

With the current weather and upcoming warmth, we are really banking on a Birkie Blizzard. It’s not a good place to be. But it’s better than canceling a plane ticket.

Weather/Cancellation Speculation: Odds rise to 27%

Yesterday we calculated the odds of a Birkie full cancelation at 20%. However, the most recent model runs have not been great, so I’m bumping the odds of a canceled Birkie to 26%.

Basically, I’m keeping other odds equal (odds of the snow not melting, the snow melting south of OO, and the course being too bare to ski) but pulling the chance of a snowstorm saving out skin down to 33%: or one in three. It seems we’ll have to thread the needle. To continue with yesterday’s football analogy: think about this as kicking a 50 yard field goal. There are basically four things—other than a block—that could happen. The kick could sail through the uprights: that’s the foot of snow on Friday. It could go wide left, which would be the storm going too far north and it raining in Hayward. Or it could go wide right, and the storm could miss the northland all together. Or it could fall short, which would be the storm taking longer to get to Hayward and not delivering snow in time.

Several of the most recent model runs have been short and left. The European model actually improved: 8″ of snow on Friday morning (so a nice kick through the uprights). But the Canadian and American models both shifted north and slowed down, meaning a sloppy Friday and maybe some snow on Friday night. That would be iffy for a race.

But nothing is set in stone. Yesterday, the models, if they were missing, were shaded right. So this may be a trend, or there may be some reversion to the mean coming up. We’re still a week away from the race, so we have several more model runs to hope that our storm will save us. Or we may see it move or disappear, a potential coup de grâce for our hopes of a tenth straight full-course Birkie.

The one thing that poor weather is good for? site visits. The past two days have been the busiest days on this site in February in its history. So, thanks for reading, I guess.


Weather Speculation: Thursday evening update

There have been years where the weather speculation thread here has been pretty benign. This is not one of those years. For the first time since 2007, we have the distinct possibility that the race could be materially affected by weather. So here’s a quick recap of where we stand a week out:

  • We know it’s going to get warm. The GFS model puts the high temperatures for the next six days at 47, 48, 49, 53, 55, 44; the Euro at 46, 46, 48, 46, 52, 36. Both hint at some rain on Monday. None of this is good: this is enough heat to eat away at the snow base, which is already below average (if there were two feet of snow, it would be fine, but there isn’t).
  • The base may survive. It may not. This is really hard to forecast. Slight differences in cloud cover at different times of day, for instance, can make a big difference. This is really a “hope for the best” type of situation.
  • There is the potential for a storm next Thursday and Friday. This could be a true Birkie Miracle if it pans out. There are eight long range model runs a day (four GFS, two each from the Canadian and Euro Model) and about 75% of them are showing at least 6″ of snow. (The last several model runs show 10, 8, 11, 1, 16, 7, 5 inches.) There’s even some climatology support: frequently warm spells in the Upper Midwest spawn “panhandle hook” type storms. But this is a long way out, and models are very volatile at this length. The signal is very strong: it’s rare to have such consistency between models and over model runs. (In fact, the “misses” have still shown the storm, but had it pushed south. Every model run for three days has shown the same storm.) But there are no guarantees here. [Update: the latest GFS occludes the storm in Iowa, possibly keeping the Birkie in a warmer sector, but maybe still drops enough snow to get by. It’s still there, so that’s good, I guess. More in the morning.]
8" of snow by 7 a.m. on Saturday. Not the best we've seen, but we'd take it.

8″ of snow by 7 a.m. on Saturday. Not the best we’ve seen, but we’d take it.

So what does this mean? It means the Birkie could be canceled. I won’t sugarcoat that. Here is my current prediction. First, I’d say there’s a 50% chance this storm materializes and we get enough snow next Friday that it doesn’t really matter if some hills burn out because there’s 6+ inches of new snow to ski on. That would be nice. This is a really high percentage guess for a storm, but it’s rare to see such consistency on the models. If the storm doesn’t materialize, I’d say there’s about a 20% chance that enough snow survives to ski a full course. Another 10% that the course might have to be ended or turned at OO (and I have no idea what this would mean for the Kortelopet). And a 20% chance the race is canceled.

You never want to place so many of your eggs in the basket of “I hope model runs seven days out verify.” This is very risky business. But that’s where we are right now. Our second-best hope is that the upcoming thaw doesn’t melt the trail. And our best hope is for a last-second miracle snowstorm.

To put it another way: it’s the middle of the third quarter and we’re down 28-3. The question is: do we have Tom Brady playing QB? (Yes, I’m an unapologetic Patriots fan. Deal with it.)

9 (warm) days to go

We still have a problem. It’s going to be warm for the next week. Five days above 40, potentially two above 50. This is no bueno. It may cool down some evenings. It may rain. The snow may last. But it will be close. It may not.

We’ve had a good run of snow years for the Birkie since 2007: the longest run of a full course being run since the 1990s. Good things may come to an end. But they may not.

I think retaining a good base with the upcoming weather may be very difficult. But if we can retain something on the ground, anything on top helps us a lot. And there’s a strong signal a week out that we may see some snow. Most of the model runs in the past few days have shown this; the ones which haven’t have shown the storm being suppressed south by high pressure. This is what to watch. Today, we’re 2/3 on models showing the storm hitting the Birkie Trail with enough snow to give us a race next week. We’ll have to watch this, closely, over the next few days. For now, if you’re a praying person, pray for snow.

(I’d like this year closest to 1998, when there was 6″ of snowpack and a week of temperatures in the 50s. That year the race was shortened to OO. Hopefully we can get a bit better.)