Think Snow, Tweet Snow !!!

Thursday, March 21, 2019

Wet snow Thursday night becomes more powdery snow by Friday night with 1-2 feet expected across the high country, less in the valley

During the last update I spent much of time getting folks "jazzed-up" (Herbie Hancock style) for the upcoming storm. We can get further mired in the fine print today which in summary reveals that though we still are likely to get a superb event, the best since MLK day I still think, we are not in that bullseye area. The juicy coastal system will phase and subsequently bomb, but will also track over interior southern New England, thus placing the Adirondacks in the more favored corridor. That said, the storm will still deliver a dose of powdery goods Friday night into what will be a blustery Saturday.

Precipitation will arrive Thursday night as a mix of rain and snow in the valley locations and a gloppy wet snow at higher elevations. At some point during the overnight hours, the wet snow will become heavy and accumulate 4-8 inches above 2,000 feet and about 1-4 inches below that. As the low pressure center continues to intensify over Connecticut/Mass Friday morning the heaviest precipitaiton is indicated to shift west toward the Adirondacks and precipitation in the low lying regions may change to a very light rain or dissipate all together for a time. This period beginning around 9 AM Friday and ending about 2PM  is the warmest part of the storm and temperatures will likely hover above the freezing mark below 2500 feet and at or just below that mark above that.

Later in the afternoon, the storm will continue to wind itself while heading into the Maine, and the colder, moist conveyor of the storm will gradually work its way from the Adirondacks into the Green Mountains. This is where the fun begins with temperatures gradually cooling into the 20's on the mountain and snow recommencing and in a drier form above 2500 feet while snow begins as the wetter variety in valley areas. Snow should continue in rather consistent fashion from Friday evening to mid morning Saturday, bringing 8-14 inches to the high country and 4-8 inches to valley locations. This will mean some wildly different snowfall totals depending on elevation ranging from a very gloppy and dense 6 inches along to the valley floor to 1-2 feet of the drier stuff above 2500 feet. Saturday will be blustery with 30-50 mph northwest winds at the summit though temperatures should stay below freezing across most of the mountain even if readings eclipse the freezing mark in low-lying areas. I continue to watch the data as it comes in and there is still some hope that the storm track is a bit further east. Should this be the case, it would greatly improve the Friday outcome, essentially nullifying much of our time above-freezing and allowing for the Thursday night snow to continue through much of the day Friday (though it would still be of the wetter consistency).

Sunday's temps will be in the twenties to start but soar to near 40 during the afternoon. It might be dry enough to preserve some of Saturday's powder at the highest elevations but this can be difficult to assess and will likely depend on the amount of sunshine (which looks pretty good). The upcoming week appears similar to the last update. Arctic will advance southeastward Monday and some snow (and a few inches of accumulation) is likely to accompany this colder push of temperatures. Tuesday appears very chilly with readings as low as 10 during the morning and only near 20 during the afternoon. Afternoon temperatures Wednesday will climb back toward the freezing mark before milder more typical late March weather prevails for later in the week. The "corn horn" will eventually sound next week but it might take a while.

Tuesday, March 19, 2019

Bombing storm to strike Vermont late this week. It will start wet and gloppy and finish big and powdery !!!

The forecast for the end of the week got more or less thrown on its head by the "Bombs Away" situation. This is what makes Vermont weather (and the rest of the northeast) so exciting. A few tweeks here and a bit more energy there and suddenly something really big happens and that really big something subsequently has ripple effects and ramification on the entire evolution of weather events over the course of several days. Terrific news for us powderhounds overall, but this amounts to a massive amount of forecast changes over the next few days and a lot to blog about.

The Wednesday weather situation looks about the same with sunshine, a cold 15-degree morning, a warm 40-degree afternoon and very little wind. The southeastward moving clipper system also looks about the same Wednesday evening as it brings a disorganized area of rain and some snow to the eastern Great Lakes region, Ohio and Pennsylvania included. What looks entirely different is a potent low pressure area off the Carolina coastline Wednesday evening. This feature looks stronger by Thursday morning and entirely intent on phasing with the incoming jet energy from the aforementioned clipper. Instead of an innocuous period of elevation sensitive snow Thursday, the strengthening coastal storm will be consolidating the available energy and most of the moisture. Most of the day Thursday will thus be free of significant precipitation and temperatures will warm into the 40's under a mostly cloudy sky.

The precipitation arrives in earnest Thursday evening with marginal temperatures. Too marginal in fact to support snow in low lying areas and supportive of only a wet snow event across the high country. The phasing of this storm is in fact so impressive, that the coastal low will get dragged inland across southern New England and bombing system will ultimately track over Boston Friday or so it seems. This means a very elevation sensitive storm Thursday night into early Friday and a lot of glop even where it is snowing. Accumulations will range from near zero across valley locations to several inches of the gloppy stuff above 2500 feet by Friday morning.

This however is where things improve. I've been going to the "Bombs Away" well a bit too often but since we haven't had a "bomb" in a few months I felt it was necessary. I've been thinking however of another song in relation to this storm from the amazing and somewhat forgotten artist Herbie Hancock. HH had an awesome era of jazz/fusion/funk in the mid 70's that has proven highly influential and one of those great songs was "Hang Up Your Hangups".  After hearing it covered this past year by another one of my favorite bands, I got to thinking that Vermont needs HH to rewrite the title "Hang On To Our Hangups". This is something that hasn't happened a lot in recent months but storms that "Hang Up" in the maritimes of Canada are truly worthy of the hall of fame treatment. The bombed-out Canadian maritime, stalled-out storm will quite literally open a highway for moisture starting at the Gulf of St Lawrence and ending over the Green Mountains. Many times, this turns out to be the most effective way to produce the epic powder in the northern Green's and those frequent occurrences very much separate out the northern and southern Green Mountains in the snow climatology department.

The strengthening low pressure area Friday will gradually help to cool the lower layers of the troposphere and turn any rain to snow across low lying areas and turn any wet snow to powdery snow across the high country.  The period beginning late Friday and extending into Friday night appears to be solid gold. Consistent snow, some of it quite heavy, gusty north to northwest winds and gradually cooling temperatures. Friday morning's temperatures will likely remain in the middle 30's at the base, cool to near freezing by the afternoon and then drop into the 20's during the evening. By Saturday we should be looking at over 2 feet of mostly powder above the mid-station and a foot of the powdery stuff closer to the base. Ultimately this will be the best score for us since the MLK storm, but its important to get at it Saturday. In spite of what will be some gusty northwest winds, temperatures will be cold enough to keep the powdery conditions in place throughout the day. Sunday's temperatures will start around 20 but warm into the 40's, thanks to the warm afternoon March sun.

As I mentioned the bombed-out storm is a big event and has ramifications on the pattern even beyond this weekend. A large ridge across the center of the country which for a time was predicted to be the major player in the weather next week will get held up and a re enforcing area of cold will descend into ski country across Vermont Monday. We could see a bit of snow as the cold air arrives Monday and we will certainly see another 48 hours or so of sub-freezing temperatures extending into early Wednesday.  The later part of the week continues to look spring-like with some "corn-horn" potential. The very end of the month continues to look potentially stormy but doesn't appear especially cold.

Was really hoping we could get one more good one however and it looks very much as if this will materialize. Be patient, conditions will be gloppy and wet for a while Thursday night at the onset of this storm and only gradually improve Friday. Accumulations will struggle to exceed a foot in many areas because of the warmer temperatures but I would not be at all surprised to see 3 foot totals near the summits. We also got some Herbie Hancock sprinkled into the blog today. He's an American musical treasure and perfect illustration of why our music blows away so much of the competition. We have such a differing array of people from so many different places bringing all that good cross-pollination magic to music. Diversity is good, take pride in it, don't fear it.

Saturday, March 16, 2019

A mostly wintry upcoming week with a good chance for some accumulating snow Thursday

Winter has made its return after the brief mild interlude and temperatures are expected to remain mostly below freezing on the hill through Wednesday morning. There are still no indications of a major storm over the next 7 days, but winter is expected to remain in place through March 24th and this includes a few chances for small amounts of snow

There's just enough low level moisture Sunday for some occasional light snow or flurries. Barring something freakish, there doesn't appear to be enough instability to support major amounts of terrain enhanced snow, but enough to bring a dusting to upwards of 2 inches. Intermittent flurries will continue through Monday though this will be combined with a few intervals of sunshine. Temperatures both Sunday and Monday will be on the chilly side of average, bottoming out in the teens during the early morning and only rising to within a few degrees of 30. Tuesday appears to be the sunniest of the upcoming 3 days and with calmer winds.

We've struggled with the big storm potential in recent weeks and I am going to attribute that to the now-vanished El Nino which has zapped all the energy out of the southern branch of the jet stream. We finally rid the pattern of the negative PNA which had focused much of the storminess out across the west for much of February but this more favorable eastern North America winter pattern appears to be a mostly dry one. Much of the country will actually be pretty spring-like but New England will remain firmly in winter's grip and after temperatures climb above the freezing mark just slightly on Wednesday, a clipper system will bring a decent chance for a few inches of snow plus another surge of colder temperatures. That snow would arrive Thursday morning and persist through at least part of the ski day. There are hints that this system could get a little extra charge as it encounters the Atlantic but the most likely scenario appears to be 2-5 inch event. The surge of colder temperatures Friday will also be accompanied by some additional snow showers and perhaps an additional accumulation.

The weekend of the 23rd and 24th continues to appear winter-like but Vermont will sit on the front flank of a building ridge over central North America. This should set the stage for at least one terrific weather days and models continue to fight about what might happen with the other. Temperatures should remain mostly below freezing at least Saturday and might only sneak above freezing Sunday afternoon.

More spring-like weather is again possible beginning on Monday March 25th and I expect 3 to 4 of the days in that week to feature at least 40 degree afternoons. This is pretty normal for the last 7 days of March. I mentioned in a tweet that there are signs of split flow in the jet stream and that the positive PNA structure is expected to remain in place if not strengthen. Split flow is when storminess undercuts the ridging in western North America and this can be a recipe for big east coast activity. This is way, way out there around the end of the month however, which makes the speculation a little futile for now.

Tuesday, March 12, 2019

Big warm spike expected Friday followed by at least another week of more winter-like temperatures

Upwards of 9 inches of new snow has brought the powdery goodness back to Mad River Glen and certainly replenished an already well-conditioned backcountry. If you like powder, get out and enjoy because we've entered into a traditional March-mode, consisting of changeable weather conditions and more frequent above-freezing temperature spikes. Late his week, we have an especially strong temperature spike which will precedes the advance of an especially powerful midwest storm system. A full dose of March sunshine will help boost Wednesday temperatures from a low of near 10-degrees to a high of near 40. Given the expected low dewpoints, snow conditions aren't likely to get too corned-up except in particularly sun-drenched areas such as the base or south facing terrain. That will change on Thursday with the help of 10 additional degrees on the thermometer and a gradually strengthening south wind.

The aforementioned wind is my big concern for late this week. I have no issues with temperature spikes in March given that they are rather commonplace, but the southerly winds ahead of that strong northeastward pushing storm system will persist from Thursday night through much of Friday. As was the case in early February, the wind has the effect of melting snow at a much faster rate than it would in calm conditions. Clouds and a few short periods of rain are also likely but rainfall amounts don't appear to be especially high, likely around or less than a quarter of an inch. The combination of wind and extended period where temperatures are above 45 from late Thursday through all of Friday will melt off a  healthy percentage of the existing snowpack. Temperatures on Friday could briefly approach 60 degrees before gradually falling back toward the freezing mark Friday night into early Saturday. There is the possibility of some new snow later Saturday across the high country thanks to the combined effect of general instability and the passage of a weak weather disturbance.

A surging PNA index will bring some welcomed warm weather to areas like Montana which have been in the deep freeze for over a month and a period of colder weather to eastern North America, Vermont included. The strength of this cold beginning this Saturday, measured by the expected amplification of the jet stream does not appear as strong the past two days and models have backed off on the possibility of any big storm for the time being. I would not entirely despair over this yet however since March is notoriously volatile and stormy and the middle of next week (around the equinox) is a period where something substantial could yet occur so its worth watching.

The PNA is expected to peak next week and subside somewhat around the time frame of March 25th though not vanish entirely. This makes the outlook for the last week of March appear mostly seasonable in the aggregate but likely very changeable from one day to the next. For those hoping for an extended period of spring-like warmth and soon, I am not expecting it, at least this month. More likely is a few sporadic days of nice weather mixed with a few more winter-like days.

Saturday, March 9, 2019

A few inches of snow and maybe some sleet early Sunday, a "corn horn" Thursday and wintry looking official start to spring

The mostly occluded storm that is spinning its way toward into the northern Great Lakes Saturday, and will subsequently push deep into Quebec on Sunday; will, as promised, brings its moisture into the prevailing, but decaying area of cold currently in place across Vermont. Because the storm has already reached maturation, and because of the lack of redevelopment along the coast, this will hardly be a particularly memorable event. Northern Vermont could certainly use a dose of snow however and this system will provide a limited supply of that. Snow should begin around daybreak on Sunday and accumulate 2-4 inches during the morning before precipitation tapers off or perhaps continues as a light freezing drizzle or even plain drizzle. Temperatures will start off the day in the 20's allowing for the snow to be of a more powdery consistency in the morning but then warm toward or even above the freezing mark during the afternoon. Looking at temperature profiles Sunday, the expected precipitation type continues to be a close call. If it comes down hard enough, most of it will be snow, if its lighter than expected we could see more in the way of sleet. My expectation is for some snow in the morning but I did want to throw out the alternative possibility.

Temperatures Sunday night into early Monday appear relatively mild, hovering mostly in the lower to middle 30's under clouds. Across the summits, readings have a better chance of remaining below freezing. As Monday progresses, the storm's original "cool pool" area aloft, better described as simply as an area of instability, will push eastward and encompass northern New England by the evening. There is limited but available moisture with this allowing for a period of snow showers beginning late in the day Monday and persisting into Monday night as temperatures drop into the 20's. An additional few inches of snow is possible with this ahead of a Tuesday which will feature early clouds and some flurries giving way to some limited sunshine and blustery conditions.

Winds will subside by Wednesday and a very strong dose of March sunshine will warm temperatures from the teens well into the 30's, possibly even 40. I can't say for certain if this gets the "corn horn" blowing since sometimes the lower dewpoints prevent that kind of thing when temperatures are confined to the 30's (even if they are above freezing). On Thursday however, readings should surge well into the 40's along with stronger southwesterly breezes. There is some talk of rain in the various forecasts I've looked at Thursday but I think any of that will hold off until Thursday night. Friday will follow as a very mild but cloudy and breezy day with showers likely but no persistent rain.

The colder, positive PNA jet structure will begin to take shape by Saturday March 16 and continue through the spring equinox. Different simulations have shown varying winter weather situations within that time frame so though I can't be specific as to what and when, I can say new snow is likely during the aforementioned period and it's even possible for a rather sizable event. One can certainly hope. 

Thursday, March 7, 2019

A few inches of snow likely Sunday and spring-like weather late next week

Much of the high country in Vermont has been in a bit of a slump in regards to new snow and finding new ways to under-perform every few days. Conditions were right in the lower troposphere from late Tuesday into early Thursday for some terrain enhanced snow but moisture has been incredibly limited and the mostly-frozen Lake Champlain has not been contributing. We have seen some snow showers but accumulations have been generally been confined to an inch or less, up and down the spine of the Green Mountains. The cold air has kept conditions on the packed powdery side and snow depths across most of the state remain quite strong. We have some good news to report in the short term outlook but more typical March conditions are also right around the corner which means warmer temperatures and changeable conditions.

Both Friday and Saturday are expected to be considerably more comfortable. Though temperatures will start in the single numbers or teens, strong doses of March sunshine and more limited amounts of wind will make for two really nice days to be on the hill as readings warm to near 30 both days. Clouds will advance into the region Saturday night in advance of a  overly-mature midwest weather system. Unless a coastal low pressure center develops and inhales all the energy from this storm, it will remain a rather garden variety event and for now, this is what is anticipated right now. Regardless, a decent period of snow is possible for parts of Vermont early Sunday, enough I think to bring a few inches of powdery snow before temperatures creep toward the freezing mark during the afternoon and precipitation tapers off as mixed precipitation.  Monday's temperatures are likely to hover above the freezing mark across low lying areas while terrain induced snow showers envelop the high country. Conditions are likely to greatly vary depending on elevation, but the collective event (Sunday-Monday) is capable of bringing 4-7 inches of snow to areas above 3000 feet and 2-4 inches below that.

Seasonable temperatures prevail for Tuesday and Wednesday which means a little above freezing during the days and well below freezing at night. Later next week continues to look more spring-like with readings into the 40's and perhaps a little bit of rain. The sound of the corn horn is getting a little closer.

Consistent with the outlook posted 3 days ago, the jet stream continues to appear to take on a more +PNA-like shape beginning around St Patrick's Day with a ridge in western North America and a trough over us. This means the warm-up late next week will be limited to a few days. The ensuing period, beginning around the time of our leprechaun celebration and stretching to the spring equinox will be more winter-like with likely talk of new snow and mostly sub-freezing temperatures. 

Monday, March 4, 2019

Underperforning storms in northern Vermont have been frustrating but winter ain't done yet

Mother Nature was not kind to the Mad River Valley over the weekend. Two significant winter storms impacted the northeast and we received a grand total of 1-2 inches. This after waiting patiently for the negative PNA jet stream structure to abate and open the door for a more sustained stretch of winter. Chalk it all up to some simple misfortune. We had the ingredients for at least one of these storms to produce and the stars just didn't align.

A widespread, broad area of arctic cold is in the process of establishing itself across Vermont and all of New England. The suppressed jet stream and weakened El Nino is putting talk of any big storm to bed for this week but there are a series of smaller disturbances that have the capability of bringing some terrain enhanced powder to the mountain. I am most impressed with the first disturbance which will approach late Tuesday night as temperatures drop from a daytime high of near 20 to the single numbers. Though there appears to be a very limited amount of available moisture, the depth of instability is quite impressive and given the addition of just a little bit of moisture, could yield a few inches of snow from a few heavier snow showers and squalls. Normally I would consider this quite likely given the setup but Lake Champlain is about 80-90 percent frozen which has an impact on some of this available moisture. Still, I consider it likely that we can squeeze at least 2 inches out of this set-up early Wednesday. The snow showers Wednesday will taper to flurries as the day progresses, a day that will be quite chilly with temperatures hovering in the teens and wind chills below zero thanks to persistent northwest flow. Another disturbance on Thursday will keep the flurries going but this very weak clipper system, or whatever is left of it, appears aimed at locations south of MRG. I would thus not be surprised to see more sunshine Thursday and a continuation of very cold temperatures with morning lows below zero and afternoon highs again in the teens.

Winds should subside on Friday and the strong March sunshine should help boost temperatures well into the 20's. The trend of moderating temperatures will then continue into the weekend but there are questions regarding potential precipitation. Some overrunning precipitation, in the form of snow, is expected Friday night into early Saturday somewhere along the east coast while a more robust storm system has an expected impact time of Sunday. The initial area of snow early in the weekend appears more and more likely to miss northern New England entirely thanks to continued northwest flow at jet stream level, keeping dry air in place. We won't miss the precipitation later in the weekend (Sunday into Monday, March 10-11) but we do risk losing the support of much of the cold. As of now, it looks like a snow to mix to rain.

Next week (March 11-15) features a bit of everything. It continues to appear a little less mild verses some of the expectations 2-4 days ago but considerably milder than this week and very March-like overall. Monday will start mild and potentially a little wet. More winter-like temperatures are then expected to return for Tuesday, last into early Wednesday and then give way to milder temperatures later in the week when we might hear the corn-horn echo through the valley.

I realize there has hardly been a plethora of good news in this post. If there is some good news, it's probably in the long range which continues to appear colder. The MJO head faked the forecasting public yet again. After suggesting for several days it was headed toward some strengthier Pacific Jet phases, it will reverse course, neutralize and perhaps reenter some colder North American phases again. The European Ensemble members have been responding most aggressively to this by showing an emerging positive PNA structure around the time of St Patrick's Day weekend. We haven't seen a good positive PNA since around the MLK holiday. I can't get too specific about what might occur between March 16th and 20th but the potential for wintry weather, especially snow along with colder temperatures has gone way up verses where it was a few days ago. In other words, winter ain't done in spite of what has been a frustrating few days.