Weather Speculation: Two weeks

Two weeks out from the Birkie means that we now have eight GFS model runs which have gotten to Birkie morning (the other major models only go out 10 days, the GFS 16). 16 days out models tell us very little. They’re not going to tell us an exact temperature, but if, for instance, several model runs were showing a big warm-up or a monster snow storm, it would be more likely that we would expect that. So we’re really just looking at trends at this point, and continuity between model runs.

First, let’s look at the NCEP’s 6 to 10 and 8 to 14 day outlook (as of this writing Saturday morning). The 6 to 10 calls for near normal temperatures. The 8 to 14 forecast suggests above normal temperatures for the week leading up to Birkie, and above normal precipitation. That said, Northern Wisconsin is on the edge of both categories: there’s a 40 to 50% chance of above normal temperatures (and therefore, a 50 to 60% chance of near or below normal) and a 33 to 40% chance of above normal precipitation. A bit above normal is fine. What we wouldn’t want to see would be a 2017-style huge red blob centered over Northern Wisconsin: two weeks out from that race, the models suggested 80% and 70% chances of above normal temperatures, and that’s what we got.

So if we let the butterfly flap its wings eight times, how does it play out on the GFS? Mostly fine. Birkie morning temperatures range from -2 to 23 degrees. Birkie afternoon from 14 to 21. The trail received several inches of snow this week, which is excellent news, and the general consensus is a couple of chances for more snow in the next couple of weeks. The models suggest an active storm track south of Birkieland, with heavy snow in the Madison-Milwaikee-Chicago area some time later this week and then again potentially the middle of next week. A couple of perturbations have lifted the storm track north towards the Birkie, which would be good, but we wouldn’t want to see a model trend far north, which could bring rain and warmer weather. This has only shown up once in the past week, so seems unlikely at this time.

Yet even that model run doesn’t push temperatures past 40˚, so it might just make for a transformed base. The models keep Hayward on a rollercoaster between -20 and +30, but don’t have a setup suggesting a big push of warm air. So, with a deeper snow base and reasonably good forecasts for the next week and trends for the week beyond, we seem to be in a good place two weeks out from the race.

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