Last night, I was all ready to post a Debbie Downer weather speculation report, with models showing lower snow totals and only a few days left before the race. But then I decided to exercise phase three of Birkie training (phase two was get food poisoning / norovirus two weeks before the race, not one; phase three is get a lot of sleep the week before race day) and go to sleep. And overnight, well, news has become better.

The last three NAM/GFS model runs are all printing out about four inches of new snow for Hayward. The ECMWF seems to be on board. And the Canadian model, while showing a bit less snow for the Tuesday storm, shows a pretty nice wave coming through on Thursday with a few inches. No warm up this week, and temperatures at race time around 10 degrees. (For what it’s worth, last year a week out we were expecting temperatures around 10—and then that dropped. In other words, don’t put away your wind briefs yet. I wouldn’t be surprised if the race started below 0.)

Oh, and recent trail reports make it sounds like even without new snow it won’t be an icy mess (well other than a few choice hills). But with a few inches of snow, it might take a lemon of a winter and make pretty good yellow gatorade.

It’s looking better. The GFS has bitten on a nice slug of snow—four to eight inches—and the rest of the models show less, but at least some, coming through. The rest of the models show similar amounts, and good golly three inches sounds like it would make a nice difference between a thin, icy Birkie and a “good” Birkie. (Six inches would be nicer, of course.)

As for race-time temperatures, it looks cool—below 20 but above 0—and the models are bouncing back and forth between clear conditions and light snow. However, I am going to go out on a limb and say that it is going to be warmer than last year. Of course, it was -11 last year, so that’s not a high bar.

With less than ten days to go, we know, well, not that much. Hopefully models will pan out and we’ll see a few inches of snow next week. And hopefully the later forecasts for race day will be for, well, not rain. But there’s not too much model consensus yet, and anything is possible. Best case scenario: 3-6″ of snow early next week followed by cold temperatures. Worst? No snow, and warm rain.

(In other words, the 18Z GFS has 6″ of new snow next Tuesday. Yes, that would be nice indeed.)

The bad news? We probably need some snow before Birkie day to have really good conditions. The good news? It’s looking more likely that we’ll get some. Not necessarily a dump (although one model run hinted at an all-out Birkie blizzard). More likely 2-4 inches next Tuesday. The last four (4) GFS model runs have shown a weakening low pressure system cut off over Wisconsin, which would lead to a few inches of snow. Nothing, of course is set in stone, and the other models don’t necessarily agree, but it’s within a week, and there’s good run-to-run continuity, so, well, it means very little.

As for temperatures, tomorrow appears to be the warmest day until the race, with highs going in to the high 30s. If we can survive tomorrow’s meltdown, the snow should do pretty well until then. And given that the Birkie is pretty important to the local economy, I’d imagine that the race organizers are going to be working to patch any thin spots in the mean time. Nevertheless, a few inches of snow next week would go a long way.

Race time weather outlooks are vacillating between cool and moist (light snow) and cold and dry. Except for the aforementioned Birkie blizzard run, which would have rain changing to heavy snow the night before the storm, a foot of snow and gusty winds. Highway 63 would be mighty interesting in that.

Quick post today because I just got back from a weekend of driving, skiing, and generally freezing to death (at least this afternoon, boom -20 wind chill).

According to the latest GFS model run, there will no snow in the next week with highs topping out in the mid 30s and dry air, so the snow should stay pretty okay. The second week—where of course it is purely guessing—would feature two shots of snow, one warmer storm early in the week with a few inches of wetter snow and a second cooler storm right before race day with a few inches of powder. This would be nice. Race day temps just above 0 with strong northerly winds. Bring out the wind briefs.

The DGEX is in a bit of agreement towards the early part of the long range forecast. The GGEM suppresses the storm track southwards with cool temperatures. The ECMWF is, who knows. The CPC automated forecast (on the weekend, there’s no discussion) is for normal temperatures and above-normal precip for Birkie week. Which hopefully would translate to the four letter S word, not the four letter R word.

In other words, things look pretty okay. The 70-10-10-10 breakdown from the other day holds. By the way, if this all makes very little sense to you, check out the weather speculation resources.

First, good news. A cold front kicked up some lake moisture (most years it probably would have passed drier, but Superior isn’t anywhere near frozen) and kicked up some snow in Birkieland. Reports are of 3-4 inches on the trail. Yeah, that’ll help. Also most years we wouldn’t be celebrating a couple inches of snow. But that snow gives some immunity to a quick warm-up, and gives a lot more leeway for rolling and grooming going forwards.

As for the long range forecast, they’ve bounced around a lot, as usual. In the last couple of days they’ve shown rain, snow, warm and cold between now and race day. But for the most part, the next week looks cold to start and warmer to finish, with no real chance of any precipitation. Next week might jump in to the mid 30s a couple of days, but no snow-sapping 50 degree readings are on the horizon. Beyond that, there’s lots of variability, but I’ve not seen a model run in the past 24 hours which would cancel the race (50 and sunny, or warm rain with no new snow) and more than one which would get the course in good shape.

Here’s some pure conjecture (i.e. I’m making up these numbers as I go along): If you’d asked yesterday, I would have given the chances of a full course race at 50%, a modified but nearly full race (at least 40k) at 20%, a shortened race (a la 2007) at 20% and a cancellation at 10%. In the past 24 hours, with a surprise coating of snow, I’d move the numbers to 70-10-10-10. It’s amazing what a couple inches of snow will do.

Finally, the past 24 hours’ model runs show the following conditions for race time. You can see there’s some volatility:

• 10, cloudy, north winds, possible light snow, new snow before race day
• 20, calm, clear, new wet snow before race day
• 30, east wind, damp, new wet snow before race day
• 15, north wind, mostly cloudy, some new snow before race day

I get excited about the weather, like many skiers, but I am no meteorologist. However, I know that there is a lot of information, and misinformation, out there and I want to share the resources I use to make wildly speculative inferences about the weather. You can use them too.

Most of the information here comes from weather models. Weather models give us a decent idea of what the weather might be in the long term (i.e. whether it will be warm or cold in a week, or stormy or calm), and short term models help us to pinpoint smaller-scale weather features and timing. Here are models and model information, in a generally descending format from longest-range to shortest-notice. There are a bunch of different outputs from the models, especially in the long range (many having to do with aviation such), but we’re only interested in a few, namely:

• 850 mb temperature. This is the temperature about 5000 feet up in the air. Above 0 C is bad. Below 0 C is better. This does not correlate necessarily with the temperature at the ground, however
• Surface temperature. This is the temperature at the surface. Got it? 850 mb and surface temperatures sometimes come in to play when discussing precipitation type (i.e. rain, sleet, snow).
• 1000-500mb thickness. This is a pretty good indicator of whether it will snow or rain (or be warm or cold). 540 is the magic number. Rain > 540, Snow < 540. With some but not too much variability. Cold air is denser, so the thickness is lower. Much more information here.
• MSLP, or mean sea level pressure. This is an output showing highs and lows, which correlate to storms.
• Period precipitation. Models usually show precipitation over three- or six-hour periods. Most models have a map showing thickness and precipitation overlaid (and usually MSLP, too) so you can see a) where there is moisture and b) where it’s cold enough to be snow.

A couple notes. Models have numerical output (tables) and graphical output (maps) and I’ll link to whatever I can. Models cycles are updated based on UTC or Zulu (Greenwich Mean) time (usually 00Z, 06Z, 12Z, 18Z), but that doesn’t necessarily correlate with their availability. I’ll mention that. Also, all the abbreviations mean something. No one really knows or cares. Oh, and beyond seven days models vary immensely from run to run, and whatever you can glean from them is, well, not that useful. But fun! On to them:

• The GFS is the long-range US government model. (And, since it’s the work of the government, it is free! Your tax dollars at work.) It goes out 384 hours, or 16 days. The model itself is here, and a numerical output can be found here. (The link is for Hayward, but replacing KHYR with any other airport, like KMSP, will give data for there.) I usually look at the 100_500_thick link on the model page, and you can then select “loop all”. The GFS is updated at 5 and 11 a.m. and p.m. (all times Central Standard Time; models don’t go on daylight time in March, however).
• The GGEM is the Canadian’s model. It’s updated twice a day around noon and midnight. The 00Z model run goes out 10 days, and the 12Z goes out seven. Maps can be found here. I generally look at the precipitation output (which includes the 540 thickness line) and the total accumulation. Remember, it’s Canadian. Everything is metric.
• The ECMWF is the European model. You have to pay money to get that one, and I don’t. However, you can compare it with the GFS for free here (you want the surface pressure comparison), which is a good way to at least see if it’s showing something similar or if it is wildly different. Or, here’s another site I just found. Look at the North America images. The ECMWF updated a bit before 2 a.m. and p.m.
• The DGEX is a US model which has some interesting outputs, like 6-hour snowfall and total snowfall, which are all available here. It runs from 84 hours (when the NAM, see below, ends) to 192 hours (3.5 to 8 days), and comes out on the 06Z and 18Z cycles, around 6 a.m. and p.m. I also look at the SLP/6 hour precip, which includes the 540 thickness.
• The NAM runs to 84 hours and has similar attributes to the GFS, but is much finer in scale. Find it here.
• The WRF model goes to 36 hours here, but I don’t check it often.
• The HRRR is updated every hour and goes for 15 hours here. Before or during a storm event it is fantastic. It has really interesting attributes and outputs. I’ll mention it more if a miracle storm is upon us.

It’s barely two weeks to the Birkie, and things seem to be, well, sort of holding on. We’re on the verge of the longest model runs going to race day, so it’s time to start weather speculation in earnest! The news going forward is very mixed. On the one hand, the current models have not been showing any major warm-ups. Without new snow, a couple days in to the 40s would probably shorten the race, and quite possibly cancel it.

The latest model run (in tabular form here and in graphic form here) shows cold temperatures and then moderation this week, and a similar pattern next week. The forecast high over the next two weeks is 36, although that day it appears there may be abundant sunshine which could, in late February, push the mercury over 40 and do a number on some south-facing hills. Precipitation appears negligible, with storms tracking south of the Northwoods, although a shift north would hit Birkieland quite nicely and is not out of the question.

In summary, there’s a decent chance of a full race if temperatures stay low and there’s a bit of new snow. But with trail conditions sounding pretty marginal, any deviation (colder and snowier or warmer and sunnier) will have major implications towards race day. We will, of course, keep you posted.

Here is our post on weather speculation resources.