Jump to content
  • entries
    35
  • comments
    55
  • views
    3,164

About this blog

Update: Future blog posts will be made as stand-alone threads in the forums. You can filter for them using the "chasing snow" tag.

 

Bryan K. Woods, Ph.D. founded Northeast Mountain Sports and publishes this blog dedicated to skiing and winter weather. He received a B.S. in Meteorology from UMass Lowell and his Ph.D. in Geology & Geophysics from Yale. He is an expert in mountain meteorology with multiple peer-reviewed publications. He worked for five years as a Senior Staff Scientist at Atmospheric and Environmental Research, Inc and its parent company Verisk Analytics. He is currently a Principal Engineer at HERE Technologies, the Open Location Platform company.

Bryan lives in Chelmsford, MA with his wife and ski tuning bench. He spends his winter weekends in North Conway, NH or elsewhere skiing. He is actively involved in the Eastern Inter-Club Ski League (EICSL) as its Secretary, and a Board member of the Makusue Ski And Sport Club in North Conway, NH and ACE Ski and Board Club in Chelmsford, MA.

Entries in this blog

 

Another week of wet ahead, then November comes

As promised, the last two days featured wet weather brought up by a strong southerly flow pumping up the subtropical moisture. I wish I could say that we're done with it, but the week ahead looks to bring very similar weather. The frontal boundary parked on top of the New England coastline isn't going to clear the region until Friday. Behind it dry weather should settle in for Saturday and the start of Sunday. However, by Sunday evening we'll see a return to the strong subtropical flow from the south bringing potentially damaging winds and strong downpours stretching through Monday. Give that it is five days out, it's no surprise that the exact details are fuzzy, but the pattern is clear as shown both in the GFS and ECMWF. Note the strong wind out of the south pumping subtropical moisture into New England. Don't get hung up on the timing or exact placement of the rain in the plot below, but note the potential for an additional several inches of heavy rain concentrated where convection trains into narrow bands. The heavy rain won't be the only story. The potential exists for damaging winds, especially along the coast. You'll find some alarmists noting near hurricane force sustained winds in some of today's model runs. It's too early to talk about that sort of magnitude. It's more likely you'll see something similar to the brisk southerly winds of the last two days. The strength of the upcoming system will depend on how well the tropical energy develops as it moves off the Florida coast. The intensity of these subtropical systems are typically poorly handled by operational models as their energy is derived from convection (thunderstorms) that are too small scale to resolve in the global models. The weather turns more seasonable heading into early November. The next window for snowmaking opens in the early morning Wednesday, November 1 and could last nightly through that weekend. As previously mentioned, humidity may continue to be an issue and snowmaking conditions look marginal. The operational GFS is currently showing a workable window, but this is uncertain. I suspect the cold here is greatly exaggerated. This window isn't evident in the ensemble mean, but I expect the ensemble to run a bit warm for a few different reasons. We're too far out to talk about it with any confidence, but I can't rule out the chance of a couple aggressive ski areas hosting some rock skiing that weekend if the forecast trends in their favor. It seems more likely that the snowmaking window begins in earnest sometime that weekend of November 4, and we see some early season openings early in the week of November 6-12. UPDATE: Just to show how touchy that Wednesday morning snowmaking windows is, here is the latest GFS ensemble temperature plot.

Weatherman

Weatherman

 

January 4, 2018 storm

Model trends today have been to the west, which is no real surprise. In this highly amplified flow the models tend to damp down such extremes in the long range. The way we initialize models (data assimilation) there are terms in the equations to penalize extreme solutions and force everything back to average. The result is often suppressing storms in highly amplified regimes like this one. The track looks to be just offshore with strong snow banding just to the west of the track. This bring heading snow bands to eastern coastal regions of New England from eastern Massachusetts into most of Maine. The White Mountains of New Hampshire into Maine will see a localized maximum as is common in coastal storms. For those of you in Vermont -- tough luck but that's no surprise. Your bread and butter are the lighter snow of upslope wrap-around. I don't mean that there won't be any snow -- there will be some upslope -- but when in these cold regimes it is the light and fluffy stuff that just serves as a top dressing. For skiers, it won't give you any float, it won't serve to reinforce the base, and it won't stand up to skier traffic. It will end up blown into the woods. If you look careful at the precipitation map above, you'll note the cellular pattern in the precipitation. This is the result of embedded convection within the snow band. In these intense snow storms, there can be pockets of elevated air that become unstable and rise upward like in a thunderstorm. This is in contrast to overrunning (stratiform) precipitation where moist air rides mostly horizontally from the south up cover cold air. The overrunning results in precipitation. Those same dynamics are at play here, but mesoscale (mid-scale) dynamics are at play that causes that overrunning area to have more energy than the air below it, resulting in overturning. A sounding from the model forecast above taken in southeast Massachusetts (where the red dot is) shows this. For the untrained eye, there are three things to see. Note the profile of "equivalent potential temperature" in the lower right. This is the temperature that the air would have if it was brought down to the ground and all the water vapor condensed. This should continue upward if the profile is stable. If it decreased with height, the air will want to convectively overturn and result in precipitation. Note the elevated unstable later around 800 mb pressure level, and a near surface instability area as well. This same unstable layer shows up in the Skew-T sounding in the middle of the page. The diagonal solid dash lines refer to lines of constant potential temperature, which are just subtly different from equivalent potential temperature -- just discounting the events of moisture. The green line is the dew point temperature, and red line is the air temperature. Where the red and green liens meet, the air is saturated. In the saturated layers, note the negative omega values in the bar plot in the lower left -- in dynamics omega is vertical velocity of an air parcel with respect to pressure. Negative omega means decreasing air air pressure and upward motion. Where the air is saturated is becomes buoyant and accelerates upward. Once the instability relaxes the upward motion slows. You can see this upward motions in the negative omega values in the two layers. The presence of these two unstable layers are likely due to two different mechanisms at play. The elevated, and stronger, unstable layer is the broad scale up-lifting. As snow falls from the upper layer into the lower, it will seed additional precipitation from the lower saturated level. This is a common situation with terrain-based enhancement and is know as seeder-feeder snowfall. S0o where does that leave us? The responsible NWS is showing a broad moderate snowfall, and that's the appropriate forecast at this time. Note that these maps don't accurately show expected terrain enhancements. The White Mountains will once again make out well from this storm. The global GFS guidance picks up on it, and the high resolution 3 km NAM really latches onto it. As previously discussed, convective dynamics are at play in this storm, and the global models do not have sufficient resolution to catch this. So give more credence to the NAM forecast in the lower plot. It's also worth noting that skiers may miss the real news worthy story. You'll hear talking heads on TV tossing around the B-word. That's a result of the strong winds being driven by the intense cold already in place that we're feeling when we go outside. The NAM is showing a taste of that. The heavier, wet snowfall in southeast Massachusetts couple with those strong winds could result in power outages. Those would be a big deal in this regime. We'll be returning to extreme cold on the backside of this storm. Those who lose power could be facing freezing pipes within hours of power loss. Temperatures will be diving sub-zero again across New England on Friday into Saturday. If you lose power, watch your pipes! So where to ski this weekend? Nowhere? Everywhere? Good luck. It's going to be damn cold. But the White Mountains will have the deepest snow pack in place, with depths in the high terrain approaching three feet. Secondary maximums are evident in the higher terrain of Vermont, but are not quite as deep, especially counting the water content of the snowpack which is helping to pad the New Hampshire numbers.

Weatherman

Weatherman

 

October skiing imminent

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.  

Weatherman

Weatherman

 

Wax those skis!

Winter is coming! Sorry for the delay. I'm currently in Montreal for a multi-day bachelor party which has been a little... distracting. But I wanted to let everyone know the good news: regime change is on the way! It's too early to be giving many specifics, but start thinking seriously about opening day in two weeks. The signs have been there for a while, and I'm now confident enough to post it. It's time to make contingency plans for skiing in late October. I'd clear my calendar for the weekend of October 28-29. The trend is for a pattern change bring colder weather to the East. The signal has been more focused around the upper Midwest, but given the recent warmth it will feel dramatically different.

Weatherman

Weatherman

 

First widespread snowmaking window in sight

I'm settled in a home with two bowls full of candy awaiting the Trick or Treaters. Yes, we're running a bit behind this year due to Sunday's storm and the subsequent power outage. On top of that today is my wife's birthday, and my mother's. Yes, both of them. But today's multi-occasion theme has me in the mood to transition to welcome November news. Snowmaking will be coming online in the foreseeable future. Killington has proven a willingness to blow snow in the most marginal conditions, even if that means that it all melts. They'll get a brief window at elevation tonight. But the window will be very limited and marginal. I doubt that stops them. The situation looks a little better at Sunday River, and they may see another even more marginal window tomorrow night. It's an operations call as to whether the light up the guns. We're in for a warm-up early next week so they'd likely lose much of what they can put down. Early next week we're looking at yet another warm up with rain moving through the region. Yuck. But on the back side the situational looks much more favorable. I'm personally planning on making my first turns of the season next week, and I suggest you too clear your calendars. Starting on Tuesday night we're looking at nightly snowmaking windows! And the temperature profiles and durations look favorable enough that most mountains will likely get in the act. Below is the mid-week forecast at Sunday River at elevation. This initial mid-week window will be nights-only which may mean that some ski areas will sit this one out. But the cool streak looks to continue through next weekend. This could provide a long enough window for most of the traditional early-season players to open if they so wish. We're still a week out so this is subject to change, but it is showing up in the ensembles of all the global models. This is about as robust a signal as you'll see a week plus out. My skis are ready! Are yours?

Weatherman

Weatherman

 

Tropical dance and regime change to follow

The next week is going to be a story of change in the East. This weekend will be (pleasantly?) warm will high temperatures reach into the 80s. For those of us yearning for winter weather, we'll need to wait a bit longer. But if you want one last shot at summer fun, Sunday may be your last chance! The 850 mb temperature anomaly map below show just how unusually warm this weekend is going to be. Notice that warm bubble in the middle of the Sargasso Sea? That's Hurricane Maria on her way north from Puerto Rico. It's too early to be talking about an exact track up the coast, but the trend continues to be out to sea. Interestingly it may actually be the decay of Jose that dictates her track. For you weather weenies out there, you're about to see some really cool dynamics in play next week. For a few days now the dynamic models have been consistently showing the remnant circulation of Jose deflecting Maria in a example of the Fujiwhara Effect. This is clearly visible in the vorticity animation. Note that as Maria runs into the vorticity maximum left from Jose off the coast of Cape Cod, she is deflected to the left of track before the steering currents push her out to sea. Once Maria move out late next week, cooler air will move in for next weekend. Expect a crisp smell of fall as October arrives next weekend. Skier spirits will soar and leaves will rustle. It should be a great weekend for a campfire in the backyard.

Weatherman

Weatherman

 

Warm weather continues

I've been meaning to post an update for days now, but there just isn't much to say. Expect the warmth to continue for at least the next two weeks. There are hints of a pattern change coming up after that, but those hints are always there. The weather models often become dominated by seasonal-scale forcing at this time of the year. Changes in the energy balance happen so quickly that they are hard to ignore. We've already seen daytime highs cool by nearly ten degrees since the start of the warm spell simply due to seasonal shifts. Even though the temperatures have cooled in that regard, we're still running well above average and will continue to do so. By now you've probably noticed that the foliage is running well behind schedule and the colors are dull at best. Expect that to continue throughout the fall. This is an overwhelmingly poor year for leaf peeping. My only comfort is that there is little to no correlation with this pattern to the winter ahead. The truth is that seasonal trends in the Northeast are difficult to forecast, and nearly impossible at this point in the season.

Weatherman

Weatherman

 

As you were

Fall sucks. All sorts of waiting around and getting your hopes up. I know we were talking about skiing next weekend, but I'm much more pessimistic now. As I mentioned before, the outcome is all going to depend on the transition, and right now that looks wet. All the way through Halloween the cold air stays out over the Midwest, and the firehose of humidity gets pumped right at us. In the plot above note the surface winds out of the southeast pumping in moist (high dewpoint). The frontal boundary remains sharply to our West. The shift in the model forecast over the last few days is both a testament to how far out we can predict, but also the error scales inherent in those forecasts. The cold, dry air is still forecast to pour south, but its position has nudged just far enough to the west to left us out.

Weatherman

Weatherman

 

Enjoy the warmth

I know some of you are looking forward to cool fall weather. Unfortunately it just does not look promising for the long term. This week will be summer-like warm, followed but a brief cool down for the upcoming weekend stretching into early next week. Surface temperature anomalies for the upcoming weekend But that fall-like weather will be short lived. Look for a return to warm weather upcoming for Columbus Day weekend. It'll likely be beautiful for getting outside but will likely keep the peak foliage confined to northern New England. Keep that chin up! My skis all went to the shop this weekend for a stone grind. For those of your with backyard gardens, you have at least another couple of weeks without having to worry about frost. It looks like we'll get a long growing season this year.

Weatherman

Weatherman

 

Opening Day comes this week

Monday evening update is posted, previous discussion continues below. It's finally here. The first turns of the 2017-18 ski season will be made this week! But before we get there we need to weather some rain tomorrow (Monday) and be patient as the snow guns come online. Looking at who is already in play, expect Killington to be making their first passholder-only turns by the end of the work week, with other early season players coming on board by the end of the weekend. Exciting! Let's break it down day by day. Monday
It's going to be warm and rainy. The end. Tuesday
The first sub-freezing air hits in the early morning. Maybe a few aggressive ski areas start blowing in the early morning hours, but they'll likely have to temporarily shut down during the day as temperatures climb into the 30s.
Just about at dusk expect the snow guns to go online. We're not talking about ideal snowmaking weather, but it'll get the job done in early November. In northern New England they should be able to make snow top-to-bottom, but that will be an operations decision. Wednesday
A lot like Tuesday. Guns go off during the day and come back on in the evening hours. For now temperatures look good to go for more top-to-bottom snowmaking that night, though again a shift of a couple degrees makes a huge difference. Once again temperatures will not be ideal, but it'll work if they want it to. Thursday
Guns go off at daybreak. It looks like conditions may not be favorable to a return to snowmaking that night. A short wave trough will be swinging through the area. If the current model solutions play out, look for two weak low pressure systems to pass to either side of us: one across central Quebec and another out to sea. With New England between two lows, expect us to be in a trough where winds turn out of the south and humidity rises. The result for us will be marginal at best snowmaking that night. Friday
After the trough passes through New England on Friday, expect temperatures to drop that evening. Sub-freezing temperatures should extend all the way to the coast. Expect anyone and everyone who wants to make snow to do so. The weekend
We're still a week out, but it looks favorable for continued snowmaking. Temperatures will likely stay cold enough to allow snowmaking throughout the daylight hours at elevation. Next week
Monday may be a fun day! The next storm system will move through the area. Right now it looks like snow for northern New England. We'll keep an eye on it and let you know more as the time approaches. The extended period looks favorable as well. It looks like we'll be in a new regime of cooler weather in the East.

Weatherman

Weatherman

 

Early December outlook

This weekend December arrives on Friday! So where should you ski this weekend? That's an easy answer: Jay Peak. They've reported 22" of snow this week. Have you seen the reports? I'm jealous.  They already have several trails and a few glades open with natural snow. The snow isn't done yet. Another several inches (maybe 6?")  is expected before the weekend. If you're not skiing this weekend, this is your opportunity to complete preparations for winter. This may be your last chance. Finish leaf cleanup, and make sure the snow blower is functioning. But seriously, you should be going to Jay Peak. Start packing. Next week Temperatures will be seasonable this weekend, but warming up into early next week. Around Tuesday - Wednesday, expect a dramatic regime change. The transition itself should bring precipitation, though the details of how that happens remains unclear. From late next week onward we'll see dramatically more wintry weather. Expect ample cold air and opportunities for snow.

Weatherman

Weatherman

 

Second weekend of December outlook

Temperature Outlook Cold air is moving into the Northeast today, and it will be here to stay for the foreseeable future. The long range forecast is for below-average forecast at least the next two weeks. Snowmakers will be working overtime. Below are the surface temperature anomalies for the next two weeks. This Weekend This weekend looks tranquil with a low chance of very light snow -- not enough to do anything but look pretty. A wave low pressure should stay just offshore. There is still model disagreement with whether light snow will reach coastal areas, but it should stay far enough out to miss ski country. Below is one of the more snowy model solutions. For those of you attending our season kick-off and demo day at Bretton Woods on Saturday, expect highs in the 20s and calm wind. The snow should be hardpack after this week's rain. Hopefully a couple of grooming cycles will allow them to recover. No Snow? While the ingredients are in place, right now there's no sign of significant snow over the next several days. Anything beyond early next weeks remains uncertain, but nothing stands out at this time. The 10-day forecast shows only light accumulations, with the possible exception of the higher terrain of northern Vermont. There they could see a total of several inches of light, fluffy snow, but nothing of the quality needed to build a base.  

Weatherman

Weatherman

 

Weather takes a turn for the wintry side

The stars have aligned over the last 24 hours as the weather model guidance has decided that it's time for winter to get started. This a much more sensical solution as all the pieces were in place. The first development is that model guidance has shifted on-shore with Saturday night's snowfall. The result is a plowable snowfall across southeast New England, with light snow over the White Mountains of New Hampshire and western Maine. Accumulations in Vermont won't be meaningful until later in the week. Another storm is expected on Tuesday which will track across New England and bring a mixed bag of precipitation. Right now it looks like a solid base-building snow event for the White Mountains on New Hampshire. Details are still sketchy this far out, but the model runs have been more consistent than usual for this range of a forecast bring snow to the mountains and rain to the coastal plain. The latest GFS model forecast below illustrates that the rain-snow line will be a question in play, but just inland of the line it's looking like several inches of mixed precipitation or wet snow. After these two systems pass, the cold sticks around for the foreseeable future. Stay tuned as much snow events are likely. 10:45 PM Update: With the latest round of guidance coming in, we're finally at the point where the high-resolution models are in range. And terrain enhancement in the White Mountains is looking good. I'm upgrading this to a Powder Day Watch. Carrying wider skis with you this weekend is recommended. Something in the 95 - 100 mm width range is recommended for Sunday. About 6" of fresh is expected for first chair at Wildcat on Sunday.

Weatherman

Weatherman

 

Coastal storm expected with severe impacts in southern New England

For the past few days I've been carefully watching the development for Friday's coastal storm. The greater than usual uncertainty has been the result of two key factors: 1) the thermal profile is going to right on the cusp between snow and rain, and 2) the system is going to be highly energetic. Robust storms like this one are difficult to forecast since the perturbations enter a non-linear regime meaning small changes in computer model inputs can result in dramatic differences in the forecast. Model solutions have ranged from a non-event to a crippling blizzard of historic proportions. As the storm draws closer, we're starting to get a better handle on the uncertainty. Nothing in out of the question yet, but here is the general idea... A cut-off low will approach southern New England and then drift off to the south. The primary impacts of the storm will largely miss ski country. Heavy snow is likely to confined to upstate New York. Expect strong on-shore flow keeping the thermal profile above bringing heavy rain to southern New England. Snow will be limited to higher elevations, except at the tail end where the snow level may drop enough to bring pasty snow toward lower elevations. Areas like the Monadnocks, southern Greens through the Berkshires, and Worcester hills stand to get higher than forecast snowfall totals if the thermal profile changes much. The Catskills look to be in the best position for reliable snowfall out of this storm. Across southern New England, several inches of rain likely somewhere in a band where the low-level jet is the strongest. But this really isn't a story focused on rain or snow, at least not on its own. Instead this is going to be a story about severe coastal flooding and widespread power outages. There is still a lot of time for things to change, but multi-day power outages are a strong possibility. To highlight the strength of this storm, check out the pronounced tropopause fold that is forecast. You're probably thinking either a) what the hell is that? or b) cool! but get to the point. The tropopause fold itself is not on consequence to this story, but is a symptom of how robust the storm will be. A strong low-level jet is going to bring onshore plenty of moisture and exceptionally strong winds just above the surface. It's unlikely, but possible, that this moisture could reach the ground as snow if the thermal profile cools, which would increase the potential for power outages as the pasty snow further burdens trees that will be exposed to damaging winds. But check out that low-level jet... Wind speeds at 850 mb (around 5,000 feet) are going to be on the order of 100 kts (115 mph) around Cape Cod. Yikes! It's an open question of how much of that mixes down to the surface, but expect widespread wind damage. Also another cool geek note: check out the gravity waves being shed from the exit region of the low-level jet off the coast of Virginia. There's definitely some numerical issues caused by the weather model, but they're just another sign of the energy in the system. Cool.

Weatherman

Weatherman

 

Climate change and skiing in New England

Today's post goes out by special request of @Los. He asks: That is a depressing thought! The good news is that your children will not be facing a world without snow, thought they almost certainly will live a much warmer world than you did. We live in warmer world than our grandparents did. Remember the prolonged cold of the winter of 2014-15? That used to be a typical winter a century ago. Though with increasing greenhouse gas emissions it's likely the changes over the next century with be even starker than that. It's important to remember that global climate change is indeed global, but not uniform. Climate changes are greater toward the poles, a process known as polar amplification. During warm periods, the temperature gradient between the poles and equator is reduced. You can see this in temperature trends to date. Although the warming is clearly amplified over the Arctic, it's not as clear what the winter temperature trend has been in New England over the more recent past. Note the very strong warming over the Arctic, but a noticeable cooling over Eurasia and central North America. There has been essentially no trend over New England. So what is going on? That's a controversial question. It seems to be clearly linked to systematically weaker Arctic polar vortex. As the Arctic warms, the vortex breaks down and cold air is no longer "locked" in the Arctic. It is free to spill down to mid-latitudes resulting in the more frequent cold air outbreaks over the continents. It may seem counter-intuitive, but a warming global climate may actually not (yet) be negatively effecting our winter winter here in New England. But why is this happening now? My favorite explanation is that it's all about the dramatic loss of Arctic sea ice, but the physical link between the loss of sea ice and weakening of the vortex remains to be clearly established. There are a number of contributing factors to the decline of sea ice, especially melting from below due to warm water transport into the Arctic Ocean. The science isn't quite there yet, and there is no guarantee that this recent trend continues.

Feeling better yet? Unfortunately the mid-winter trends don't apply to the fall and spring shoulder season. There is very strong evidence that the duration of winter is shortening on both ends, even though the core of winter isn't changing much. Until about 15 years ago, this trend was largely being offset by an increase is snowmaking coverage resulting in ever longer ski seasons, but that is no longer the case. While snow guns are becoming much more efficient to operate, they haven't changed the basic underlying thermodynamics. Ski season is starting later and ending earlier., and this trend is expected to continue. The figure below shows the expected number of days with snowcover under two different emission scenarios according to a climate model. The model predicts the snow season to shorten by at least two weeks on each end. I hope this gives you a better idea of how climate change is likely to impact skiing in New England. Low-elevation ski areas, especially in southern New England are likely to suffer the most. The impacts will be most dramatic on their ability to open early season as warming temperatures make snowmaking temperature less certain in advance of the Christmas season. On the plus side, skiing at Jay Peak and Wildcat is likely to become significant more tolerable. Don't think the industry is in denial. Why do you think Les Otten has such a keen eye on the Balsams?

Weatherman

Weatherman

 

October regime change

There's no doubt that October 2017 has been warm so far. The foliage season is an unequivocal bust. So let's look forward to ski season! The next week is going to be a beautiful stretch of warm and dry fall weather. It'll be a great time to get some yard work done and tie up all those loose ends before ski season arrives. I'll personally be staining my porch railing this weekend. But the warm weather is going to come to an abrupt and wet end in the middle of next week. Behind this transition, colder air will move in for the last weekend of October. How that transition occurs is an open question, but there's plenty of energy to work with. Below is the latest GFS model run, but don't read too much into it. The transition circa Wednesday, October 25 is likely to be a dynamic one. There looks to be plenty of subtropical moisture coming into contact with the cold air burst. Recent model guidance suggests we'll be looking at a robust storm crossing being fed by a strong low-level jet. The snapshot below shows an example of this, with the color scaling showing the 850 mb wind speed. (Note: 850 mb represents approximately the elevation of the high peaks in New Hampshire) After this dynamic system clears the area, I expect productive snowmaking temperatures over the weekend. The plot below shows the ensemble average lows on Saturday night. I expect to see colder temperatures than this at elevation. I don't expect to see any ski areas open on Saturday, but it still looks likely we're talking about skiing somewhere in New England by Halloween. Sunday, October 29 is still in play too. How the Wednesday transition plays out is likely the key.

Weatherman

Weatherman

 

Opening week weather update

Monday afternoon update It's finally here. The first turns of the 2017-18 ski season will be made this week! Snow guns will be firing up tonight across New England. Looking at who is already in play, expect Killington to be making their first passholder-only turns by the end of the work week, with other early season players coming on board by the end of the weekend. Sunday River has already announced a weekend opening, and Bretton Woods may join in. Exciting! Let's break it down day by day. Tuesday
Snow guns will be running in the early morning hours at elevation. Lower areas will hold off. Most areas will have to temporarily shut down during the day as temperatures climb into the 30s. Northern New England should be able to keep the guns on at elevation at places like Sugarloaf, Wildcat, and Stowe. Just about at dusk expect the snow guns to go online. Temperatures and humidity will be a prime for a early November window. At night snowmaking should be able to go all the way to the base. Wednesday
A lot like Tuesday. Guns go off during the day and come back on in the evening hours. For now temperatures look good to go for more top-to-bottom snowmaking that night, though will be warmer than Tuesday night and a shift of a couple degrees makes a huge difference. While not ideal at low elevations, it is a workable window. Thursday
Guns go off at daybreak. It looks like conditions may not be favorable to a return to snowmaking until after midnight A short wave trough will be swinging through the area. If the current model solutions play out, look for two weak low pressure systems to pass to either side of us: one across central Quebec and another out to sea. With New England between two lows, expect us to be in a trough where winds turn out of the south and humidity rises. The result for us will be marginal at best snowmaking at best. Friday
After the trough passes through New England, expect temperatures to drop to stay below freezing all day. Sub-freezing temperatures should extend all the way to the coast. Expect anyone and everyone who wants to make snow to do so. Near record cold temperatures mean an excellent stretch of production. Saturday
Snowmaking continues all day Saturday. By now you should be skiing. Next week
Winds turn out of the south on Sunday, and temperatures rise above freezing by mid-day. The next system moves through late Sunday into Monday. It's too early for details, and rain vs snow remains to be seen. We'll keep an eye on it and let you know more as the time approaches.

Weatherman

Weatherman

 

More cold on tap for next week

I'm looking at the forecast for the next several days, and I'm not impressed.  Thursday we'll see widespread rain across New England. The ECMWF model is holding onto a wet snow paste job across the White Mountains, but the GFS is going rain. Either way, the thermal profile is going to be close. I'm leaning toward a washout. On Saturday - Sunday, we'll see another wet weather system move through. That one looks to start as snow and quickly change to rain. I'd rather not dwell on this. My goal is to make this a ski weather blog... not a rain blog. Do I have any good news? On the back side of the storm we look to transition into long-lived cold weather in the East. Next week will bring sustained snowmaking weather for Thanksgiving. Let's put up some pictures with lots of blue! Below are the temperature anomalies for next week (top) and Thanksgiving Day (bottom). The net result will be plenty of productive snowmaking weather. This season looks to be off to a health start. Terrain expansion is come quickly.

Weatherman

Weatherman

 

Pre-Thanksgiving weekend outlook

The thermal profiles are timing are looking very close, but I've become more optimistic that there will be some good skiing to be had for this weekend. Let's break it down in brief. Thursday The White Mountains look to survive Thursday's storm with a net-gain of snow, especially at elevation. Just enough cold air is going to hang on aloft to counteract the  rain/snow changeover. The mixing line looks to go up to about 3,000 feet at times. Vermont will not be so lucky as they receive a little snow by mostly rain on Thursday. At least the mid-week timing will give snowmaking and grooming systems a chance to catch back up. The snow in the White Mountains will be the pasty variety that will hopefully freeze into place. Look for total accumulations of around 1-3" at low elevations, and on the order of 6" over the higher terrain at places like Wildcat. Saturday - Sunday Looking forward to the weekend, everybody is likely to see snow transition to all rain. The good news? The rain will fall largely overnight Saturday into Sunday. Right now it looks like the skiing hours will not be severely impacted by the rain. Saturday especially could have nice conditions in areas that receive a net benefit of snow this week. Below is the meteogram for this weekend in Pinkham Notch. Where should I go this weekend? It's definitely a White Mountains weekend. Wildcat looks to be in the best position, though they'll offer the least terrain options. Depending on exactly how things break, Bretton Woods, Loon, and Sunday River could all do well.  What comes next week? At least early in the week their will be a good snowmaking window following this weekend's storm. Around Thanksgiving Day the weather turns more questionable. There's a broad range of possible outcomes ranging from a Nor'Easter to blow torch warm. I'm not going to get pinned down on any specific forecast quite yet.

Weatherman

Weatherman

 

Initial Christmas forecast

Please don't panic. Life will go on. But this Saturday it is going to rain. Vermont will get the worst of it. As is usually the case with these inside runner storms, the frozen precipitation will hold on the longest over the White Mountains of New Hampshire and into Maine. They made actually see a net positive gain in snow depths (base builder event) especially at places like Wildcat, Sunday River, and Sugarloaf that sit on the north side of the White Mountains. The high terrain can act as a protective barrier keeping the cold air locked in place for longer. It won't stay snow there, but it will contribute positively to the water load in the existing snow pack rather than melting it. The good news is that this may not ruin the whole Christmas week. For those of you with travel plans on Christmas day, please keep an eye on the forecast. Right it looks like a storm is brewing which will refreshen our snowpack bringing widespread snowfall to the higher terrain. So after a rain and then a snow storm, what is the net-net gain? The White Mountains look to come out nicely. It should be a great Christmas week for skiing in New Hampshire.

Weatherman

Weatherman

 

Sunday will be subtle

I'm happy to be able to put forward a remotely optimistic weekend outlook. Some light precipitation (of mixed phase depending on location) on Friday night will give way to a beautiful day. Saturday looks to be a warm and sunny days with temperatures in the 40s in the valleys, and 30s at the summits. But all eyes should be focused on Sunday, which looks like a classic warm air overrunning scenario. In these situations, Vermont typically starts as snow and switches over to straight rain. But northern New Hampshire into Maine can be a very different story where cold air damming hangs tough. Looking toward Sunday afternoon, snow may still be the dominant precipitation over the White Mountains and northeast into Maine. But the temperature profile is going to be borderline. The exact details will depend on to what extent a secondary surface low develops off the New England coast, which will help to reinforce the cold air damming. If this lows fails to develop, we could be left with freezing rain or a straight cold rain. Optimistically so far it looks like the White Mountains will see a 6 inch paste job on Sunday. For those of you savvy on Skew-T diagrams, note the deep layer of overrunning warm air all the way up to 650 mb. That nearly isothermal layer looks to stay just below freezing, and should lead to a pasty snow, but it won't take much of a shift to flip it. Updates will be necessary as the storm approaches.

Weatherman

Weatherman

 

Widespread snow expected on Wednesday

It's no secret that March is the snowiest month of the year, and fortunately this year looks to preserve that generality.  A Nor'Easter will impact the region on Wednesday bringing snow stretching into Monday morning. Widespread moderate to heavy snow is expected from a band of 8-14" stretching across much of ski country. Locally deeper snowfall is possible, but moderate temperatures should limit the fluff factor keeping accumulations down. The latest GFS snowfall forecast will give you a general idea of the pattern. For much of the area, especially at lower elevations, expect a wet snow paste job. It'll make excellent base snow, but don't be looking for a blower powder day. As it stands the surface temperatures should be borderline in many areas, but plenty of cold air exists aloft. There will be little to no chance of mixed precipitation, so icing is not a concern. The skew-T below from the Monadnocks shows the plentiful supply of cold air aloft and deep later of moisture. What does the mean for skiing? Wednesday night should be fun where night skiing is available at places like Shawnee Peak, Gunstock, Pats Peak, Crotched, and Wachusett -- though temperatures at the latter bear watching for any rain mixing in. Thursday morning should bring knee-buster snow to much of central New England. Even higher elevation areas like Wildcat and Cannon will be looking at dense, though hopefully drier, snow and not champagne. Accumulations in northern Vermont will be lighter on Wednesday night as is typical with coastal storms. For Thursday I'd head to northern New Hampshire in search of dryer snow even if accumulations aren't as high. It'll be a hunt for quality over shear quantity. Given that Wildcat already has natural terrain open (with very thin and scratchy cover) courtesy of last Friday's nsow, they look like the best bet. As the low passes southern New England, it is expected to wrap up and move onshore into Maine. By this point snow should be wrapping up in southern New England, but the next phase of the storm will start, and this one isn't being discussed much yet. Expect the talking heads to catch up with it soon. The potential of heavy upslope snows exists for the Friday timeframe at which time the low will be inland. Wrap-around flow will be pumping Atlantic moisture into the spine of the Green Mountains. I'm not touching any potential accumulations so far out with an upslope event, but the typically favored upslope areas look to be in great shape. I'd start thinking about making plans before things get booked up. The plan for this weekend depends on what type of skiing you're looking for. For skiing groomers with maybe a little off-piste, southern Vermont looks to be in the best position given the snow they received on Friday coupled with Wednesday's upcoming storm. Groomed trails should be in great shape. If you're a powder hound looking for the trees, head to northern Vermont. Given the upslope nature and current base depths, Bolton, Stowe, Smuggs, and Jay are looking promising for the weekend. A bonus wild card in Bretton Woods who will do okay on Wednesday and can make out well from upslope flow. They have practically zero base depths already, but New England's only lift-serviced golf course doesn't need much snow to open its ungroomed terrain. Looking to next week, there is another chance of a storm in the early week (Tuesday?) timeframe. Then things should moderate back towards spring conditions in time for St Patrick's Day weekend. With natural snow on the ground, it could be a beautiful weekend.  

Weatherman

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.  

Weatherman

Weatherman

 

Hello world!

Welcome to the inaugural post of "Chasing Snow." This blog will feature weather in New England with an emphasis on winter weather and skiing. How often will it be updated? As frequently as needed. Expect post to slow down over the weekend or other times when I am too busy skiing to talk about the weather. Will you tell me the best place to ski every weekend? Absolutely! At least I hope to give you the information you need to make an educated decision. What content will you provide? Expect more than a simple forecast. As a reader I hope you'll learn something from this blog. Look forward to technical but accessible forecast discussion. When appropriate, pretty pictures will be used. What are you waiting for? Cold beer. Snow. Eternal fame and fortune. My wife to get home so I can eat dinner.

Weatherman

Weatherman

 

Subtropical hybrid coming our way

As promised, a potent October storm is heading our way. I know I promised this would be a ski weather blog, but I might as well post something to give me something to do this morning. Bottom line is watch out for strong winds and heavy rain. Coastal flooding is not a concern as the tides are low. I'm not expecting widespread flooding, but it sure is going to be wet! Expect widespread 2-4" rainfall totals. See the NAM rainfall forecast below. The real threat with this storm is going to be strong winds, especially along the coast. Much of the energy is coming from Tropical Depression Eighteen which is tracking up the coast and will probably strengthen to a tropical storm. As the tropical moisture interacts with the mid-latitude energy, winds will continue increase. It looks like the subtropical core, and the strongest of the winds, will remain just offshore. Even with the core offshore, expect wind gusts over 50 mph leading to power outages, especially in coastal areas. The plot below shows the forecast sustained wind speeds. Looking past the storm, we'll see at least a few nightly snowmaking windows in the first several days of November. The guidance is mostly consistent with this, although it's not clear if there is going to be enough opportunity to get on the snow. It seems very unlikely that we'll be skiing by next Saturday, but the snow guns will likely be running at night. Maybe we'll see an opening shortly thereafter?

Weatherman

Weatherman

Mobile Apps available!

Please try our mobile apps for iOS and Android

×