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Weatherman

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Everything posted by Weatherman

  1. Then I hesitate to suggest southern Vermont. There isn't much base there to underly the fresh snow.
  2. Any snow tire is a good idea over an all-season.
  3. Maybe? I'm not ready to give any specific mountain recommendations yet. The consistency of the snow will be the biggest question. And existing base depths giving you a surface to work with.
  4. Weatherman

    MLK Weekend 2019

    This MLK weekend promises to be a great one for the New England skier. We're facing a sizable snowstorm Saturday night through Sunday. Look for widespread accumulations of a foot or more across ski country. Amounts will be highest in the White Mountains and southern Vermont, with less amounts as you move north into Vermont. Cutting to the chase, here are the latest snowfall forecasts from the National Weather Service. I think those amounts look like a decent guess for New Hampshire and Maine, but are overdone in Vermont. Yesterday's guidance was putting on crazy numbers over New England. For that reason I held off issuing a forecast until today when a more realistic picture has emerged. The most stable story so far as come from the European's model ensemble average. As ensemble is the same model run over and over with slightly different conditions and averaging the results, which gives a broad expected value. For a while now the European ensemble has been showing an average snowfall of about 15". As much as I'd like to drone on about the snow, I think that misses the main story of this storm. There will be plenty of cold air pouring into New England which should ensure snow in ski country, but it creates a strong frontal boundary across southern New England and coastal regions. The headline maker in this storm very well may be significant ice accumulation along the coastal front. The both the GFS and European model show this clearly. Below is a model forecast for Sunday afternoon from the GFS, and a total accumulated freezing rain from the ECMWF. Both models show a band of heavy icing across southern New England. This would lead to widespread power outages. However, I think the story may not be quite so dire. Especially considering it is a few days in advance, I think the models are underestimating the cold air at the surface. Surface temperatures just west of Boston look to stay in the teens throughout Sunday. Not only will the preceding air be cold, there are strong signs of this cold air reinforcement in the model vertical profile. Note the winds out of the north and northeast at the lowest altitudes. This should be cold enough and deep enough to yield sleet rather than freezing rain, but we'll need to revisit this as the day approaches. But if you're reading this, you probably care more about skiable snow totals. The easiest statement I can make is that I expect a little over an inch of liquid equivalent precipitation across much of the region. The storm is so progressive (quick moving, positively tilted, nearly open low) that it's hard to imagine much more than this inland of the coastal front. How this translates into snowfall depends strongly on the snow-to-liquid ration (i.e., the fluff factor). A rule of thumb of 10:1 ratio suggests a broadly distributed accumulation of 12-15" consistent with the weather service's forecast for NH and ME. You can see this in the latest mesoscale guidance if you ignore the numbers over southern New England where sleet will likely keep numbers way down. But what about if the snow is fluffier? This possibility is supported by the surface temperatures in the teens. That's plenty cold enough for ratios up to 20:1, assuming that those temperatures are maintained in the snow growth zones aloft. Using the same liquid equivalent precipitation and allowing for the ratios to vary with the surface temperature you forecast accumulations close to two feet in northern New England, and greatly reduced accumulations in southern New England. The fluff factor is going to be the decider in the snowfall guessing game. So what's the realistic expectation? Probably a mix of these two possibilities. The GFS gives a reasonable first guess. Note the starkly difficult accumulations over the Lakes Region of NH vs the White Mountains. What's driving this difference? It's the temperature profile aloft and where that places the dendritic growth zone (DGZ). That's the region of roughly -10 to -20 Celsius. To maximize snowfall, you want a deep region of these temperatures that also has saturated air rising upward. That maximizes the product of dendrites, which are the classic fluffy snowflakes that you are probably imagining. The temperature and humidity profile in the atmosphere can lead to a variety of snowflake shapes. Looking back at that snowfall forecast disparity between the NH lakes and mountains, let's look at the model's vertical profile forecast. First the Lake Region: Note the narrow dendritic grown zone (DGZ) show on the left column with the red dashed lines. The red-purple bars are the air's vertical motion expressed in pressure-based coordinates (omega) where negative omega values mean the pressure following an upward-moving air parcel is decreasing. Even though this region has saturated air and strongly upward lift, the DGZ is narrow and most the prime snow generating region will produce other shapes of snowflakes leading to a lower fluff factor. A similar plot just to the north over the White Mountains will show a slightly colder profile, but a greatly expanded DGZ and therefor higher fluff factor.
  5. That's the big questions for the mountains. The temperature argue for high ratio blower. But thus far the dynamics argue against it. Will be interesting to see what the higher res guidance shows tomorrow.
  6. There's a lot going on in those images. I'm seeing a more coherent picture now. I'll write up something this afternoon. Gathering some images now. Maybe I'll steal those from @Flying Yeti
  7. I'm still trying to decide myself. I'll be basing out of North Conway this weekend. There are lots of possibilities. The most firm plan is probably Cranmore on Monday,
  8. Fair enough. If I want to drive traffic to this site, I need to be hyperbolic. Unfortunately I suffer the curse of being an educated professional.
  9. I agree. This storm is fairly progressive. It's hard to imagine that level of accumulation in such a widespread area. I'm happy to believe it in jackpot areas of mesoscale enhancement.
  10. It's still too early to be talking about details on the mixed bag along the coastal front. The potential is there for heavy icing. Or two feet of snow. The thermal profile will be telling. I'll take a fresh look this afternoon and post something.
  11. The NWS snowfall maps look about right. We're about what I was expecting yesterday. Back down to Earth.
  12. This is the map that catches my attention: That's the mean snowfall from all of the European ensembles. Those are some big numbers for an ensemble mean. But as big as the snow numbers are, that ice forecast would be the main event if this ever materialized.
  13. Okay... here is my story. I'm staying quiet on Chasing Snow until I can be more confident with actual numbers. Why am I so nervous? Because we are too far away. Because the upstream energy is still out over the Pacific, there is a lot of uncertainty. My biggest concern right now is the thermal profile. There's going to be plenty of cold air entrenched over Quebec. And plenty of moisture being pumped up from the south. Where the front sets up is the huge question. Some model runs are showing almost comical amounts of freezing rain at the boundary. For example, the latest European model puts out over an inch of freezing rain in places. How much snow are we talking about? Inland of the front, well over a foot. Exact amounts will vary based on things like the track of the storm and temperature profile. Just for fun, let's throw out the latest American model forecast for total accumulation through Monday. The European model is consistent with these general numbers, except it locally shifts them around the map. Hopefully you can see why I am going to sit on my hands. I'd be crazy to start announcing these kind of numbers four days in advance. Odds are these numbers will come down. Regression to the mean.
  14. I'm debating what to do about a blog post. I'm not ready yet to put forecast totals out there. It's premature for that. I am confident in a juicy storm, but that's where the confidence stops. Yes, it could be big.
  15. My expectation is that the Cat will spin.
  16. Took the car in for battery and alternator testing. Both were fine. Sad.
  17. I'm leaning in that direction. They said that they were confident it was just a software problem, but if the problem persisted it would require a new 4WD ECU. Well the software update fixed nothing.
  18. I'm starting to get excited. Friday looks like. Sunday looks like the main event. Still too far out for details, but a Chasing Snow post will be coming this week. But where do I go this weekend? So many options! Looking at my ticket supply and cross-correlating with blackouts... Black (NH) Sunday River Shawnee Peak Cranmore Crotched Attitash Wildcat Bretton Woods Cannon Middlebury Stowe Jay Peak Damn. Time to start burning tickets.
  19. You're convincing me to go this season. I've got a couple tickets for the place. May tag it onto a Stowe trip. Better start making plans!
  20. You're absolutely right. And the fact that they repaired this lift makes me sad. I have to imagine they'll consider the issue closed. If this mess doesn't catalyze a new lift install, I don't think anything short of a catastrophic accident with injuries would do it.
  21. Wind scraped it clean? All the snow in the woods?
  22. Something? Sure. Lots of uncertainty though. I’ll hopefully have a post when things are clearer. Sent from my iPhone using Northeast Mountain Sports
  23. Cold today. Only got 5 runs, maybe even 3 depending on how you count. Wife had a bad day and was complaining constantly about being tortured and not feeling her feet. I didn't think it was that bad, but I was prepared.

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