Jump to content

Leaderboard


Popular Content

Showing content with the highest reputation since 09/22/2018 in Blog Entries

  1. 4 points
    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.
  2. 3 points
    Stop me if you've heard this before... we're looking at another great weekend of skiing. And it's only mid-November! Thursday night into Friday will bring the third snow storm in a week to much of ski country. This is the part of the discussion where I'd typically show you the model forecast maps for snowfall accumulation. I'll do that this time but please be aware that I think they're all crazy. Seriously the simple snowfall algorithms are not handling this well. They are either crazy high in the Mid-Atlantic or really underplaying it in the mountains. Let's jump in and have a look. Using a simple 10:1 snowfall ratio: No. Just no. That's crazy town in the Mid-Atlantic into southern New England. To be fair to the modelers, there are more complicated snowfall schemes. So using that same model run and a more advanced microphysics scheme... This lays out much more reasonable numbers in southern regions, though the mountain accumulations are under-done. The real story in much of southern New England (hi Wachusett!), is going to be icing. That very well may be the headline issue across the region. I'm a little concerned about power outages as a result, but not ready to broadcast that too loudly, especially considering that winds will not be an issue. A look at the Worcester precipitation breakdown is showing a whole lot of ice though. So where should we be skiing this weekend? Smart money is on Wildcat or Sugarloaf. Both already have a base on the ground and off-piste skiing should be in play. Look for around 8" at both mountains out of this storm. Vermont ski areas should see a widespread 6". Snow will start late Thursday night and last until early afternoon Friday. A closer look at the envelope of snowfall forecasts for Rumford, ME will serve as our proxy for both mountains. The high-resolution guidance envelope is squarely in the 5-6" range, but mountain enhancement will get you to the 8"
  3. 3 points
    Wax those boards, boys and girls. We have a genuine powder day coming up on Saturday, in October! Powder might be a bit of a stretch. Dense snow is expected. A paste job is likely. This weekend we'll be skiing at 4 mountains in New England: Mt Snow, Killington, Wildcat, and Sunday River. Of those, Wildcat is easily the best bet. They reported nearly 10" of fresh snow today. They are likely to receive the most snow on Saturday, and they are offering top-to-bottom skiing off the express quad. Look for total daytime snow accumulation at Wildcat on the order of 4-6" on Saturday. Despite talk of strong winds, I am not expecting it to be an issue at Wildcat on Saturday. Overnight the snow is likely to turn to a mixed bag, and then do rain on Sunday morning. It remains to be seen if we can sneak in some good runs on Sunday morning before it completely changes over. What is the ski of choice for this weekend? 90-something mm underfoot seems like the right play. And rock skis will be a must. Depending on conditions, poaching may be called for. Next week looks like continued cool and unsettled, but mostly rain, in the the early week. Warmer weather moves in late week, and turning cooler again for next weekend.
  4. 3 points
    Attention snowmakers: I hope you rest up tonight, because Wednesday night shortly after dark it will be time to get down to business. We're expecting at least two prolonged snowmaking windows. The first Wednesday (10/16) night into Friday morning, and another Saturday night into Tuesday morning. Below is a modeled temperature timeline for Jay Peak. Note that temperatures on Sunday and Monday may not stay cold enough to allow daytime snow production. With the arrival of the cold air on Wednesday night, we should see some accumulating snowfall at elevation in northern New England. Except for a stay coating which will quickly melt, don't expect any impact at lower elevations. So will we get any skiing in this weekend? That really depends on what daytime temperatures and humidity do during the day Thursday. Dewpoints in the teens mean that humidity won't be an issue. At the moment it looks like high temperatures should stay cold enough for productive snow making above about 2500 feet. It's possible we'll have upper mountain skiing on offer at Killington and Sunday River this coming weekend. If base depths aren't there in time, skiing early next week seems like a safe bet. By the weekend of October 27, anybody who wants to open should be able to do so. A third snowmaking window setup late next week Wednesday into Thursday. Looking past the weekend of October 27, the pattern turns warmer. The days surrounding Halloween should be back above freezing with temperatures trending near to above average. Beyond that is too far to see.
  5. 1 point
    Good news skiers! Friday night will bring an elevation snow storm to northern New Hampshire and Maine. After getting off-piste in 15" of natural on October 27 at Wildcat, this is more welcome news. Sorry, Vermont skiers. Once again you'll be missing out. The thermal profile is such that the valley will likely not see any accumulation. This is likely going to be something that only accumulates about about 1,700 - 2,000'. Look for snow in the notches and mountains, but not the low terrain. Best place to ski this weekend? Hands down Wildcat again. After the storm moves through, we'll enter into a prolonged snowmaking window. We're looking at several days (at least a week) of below-freezing weather that should allow a lot of mountain to open going into mid-November. Below is the 5-day temperature anomaly map for heart of the window. Before people criticize me for not mentioning it... yes, there is a chance of a substantial snow storm next Tuesday. For those ski areas that choose to operate mid-week (that's a short list), there could be some great skiing. We'll have more on that when we actually have a better handle on what to expect. In the interim, here's your teaser:
  6. 1 point
    The time for stoke is now. Are you ready? October skiing is highly likely this year. So when does it start? Look for snow guns to come alive this Wednesday evening (October 17). Thursday night will be even colder. Look for a hard freeze almost all the way down to the coast. Below is the National Weather Service temperature forecast for Killington Peak. Freezing temperature should be widespread Wednesday and Thursday nights. Most ski areas should lose snowmaking temperatures at the base during Thursday afternoon, but should maintain them at elevation. A few higher elevation areas like Wildcat may be able to maintain top-to-bottom temperatures throughout Thursday. But none of those areas tend to blow top-to-bottom so early in the season. Below is a chart of Thursday afternoon temperatures. It's too early to say whether we will see turns being made this weekend at typical early players like Sunday River, Killington, or Bretton Woods. We'll have to wait until we see exactly what conditions materialize before we make that call. But I strongly expect to see skiing by Saturday, October 27. Next week looks to be well below average in temperatures. There should be multiple nightly snowmaking windows. Most ski areas that want to have October skiing should be able to do so. Below is the 5-day temperature anomaly forecast leading up to that Saturday. Get stoked! I'll be doing some ski tuning this week.

Mobile Apps available!

Please try our mobile apps for iOS and Android

×
×
  • Create New...