Friday, May 4, 2018

Winter 2017-18 gets high marks for longevity and resilience but one can't forget the nasty interruption

If nothing else, one has to admire the persistence and certainly resilience of this most recent winter. After reaching 70 degrees in parts of the Mad River Valley on February 21st, the mountain failed to see any matching warmth until late April or early May. The past winter was unique for its longevity and appreciated for the longer, more sustained cold outbreaks. That said, the 7-week stretch which began on that catastrophic Friday January 12th and extended through February was very unappreciated and severely crippled what is traditionally the heart of the Vermont ski season. A 2nd straight March recovery was epic, but it would be nice if we could reach March without needing a "Hail Mary" to save the season. 

Going back to early last autumn, it looked as if the unabated succession of anomalous warmth across eastern North America had broken. The summer was milder, autumn appeared to be arriving quickly and perhaps we could align ourselves for a succession of cooler months that might extend through the cold season. Then, for the 3rd consecutive year, Vermont experienced an autumn blowtorch with summer-like heat late in September and very warm weather for much of October. When "El Torchy" type patterns linger for such a duration, I tend to get concerned there are extraneous sea-surface temperature forces that are steering the outcome. Indeed, one could make that case given the configuration of sea surface temperature anomalies in the mid and high latitude Pacific and what appeared to be a building La Nina in the equatorial Pacific. Some of those sea surface temperature anomalies shifted in November however and the blowtorch abruptly ended. Winter didn't exactly break the door down in November but it did make itself known. Temperatures were generally below average and the mountains secured 10-15 inches of snow by the Thanksgiving holiday with a favorable looking pattern emerging for early December. 

The Arctic Oscillation (AO) provided a massive boost for the colder weather both in November/December and the season generally. By way of comparison, the 2016-2017 winter featured an AO that averaged over an index of 1 which in the aggregate is quite substantial while 2017-2018 featured an AO that was a shade below zero. The effect of this was felt instantly. Though the state saw a few mild days very early in December, a somewhat blocked arctic combined with ridging in western North America to produce a nice succession of sub-freezing temperature days beginning around December 7th. Lighter snows accompanied the colder weather initially but a clipper system arrived on December 12th, blew itself up into a full fledged winter storm and deposited over a foot of snow on the high country by the end of December 13th. For almost 2 months (way too long thinking back), the 12/12-13 event was the best of the season. The colder weather was more of the garden variety type through mid December but the pattern strengthened as the month progressed. There were significant questions relating to all this, as it appeared that a developing block across Alaska would be in direct competition with a building ridge across the southeast United States. Would another Christmas holiday feature a big thaw or would arctic air prevail ? In the end, the arctic cold won and won big. Christmas weekend saw some snow to ice and Christmas Day featured some powder though not as much as we might have liked. The ensuing days were brutally cold with temperatures spending much of that period between December 27 and 31st below zero. 

The onslaught of cold continued into the New Years holiday weekend and through the first week of 2018. All sorts of terms were thrown describing the deep freeze, my favorite being "The Arcticgeddon". Though it was impressive, sustained outbreak of extreme cold are not uncommon and typically impact much of the eastern seaboard every 2 years or so. For Vermont, the cold rivaled and even exceeded in some instances that of February 2015 with nighttime and morning readings of -25 and daytime temperatures failing to climb above zero both on January 1st and 2nd (the coldest two days of the winter season). The northern green mountains were hit with a unique warm advection snow event late on January 2nd, but for the most part, the period after Christmas through the first few days of 2018 was dry thanks to a suppressed storm track and the very shallow stable layer of cold that typically accompanies the polar vortex type events. Coastal areas did get a big impact from what many referred to as the "bomb cyclone" on January 4th. Meteorologically speaking, this was a truly mesmerizing storm since it strengthened to a hurricane-like intensity (~970 mb), producing 30-50 foot swells along the Massachusettes coast that were captured in full fury on YouTube (I highly recommend looking this up if you haven't seen it). I've provided another link here 

Scituate, MA video from 1/4/18

The storm stayed offshore but nonetheless caused a healthy swath of cold, powdery, snow in coastal sections and grazed Vermont with a few cold inches. Wind chills were 40 below or lower at the summits that day and into Friday making the skiing a bit of a challenge, but the snow was piling up and the season (aside from the extreme chill) seemed to be firing on all cylinders.

And then came January 12th. There were some glaring signs that the arctic cold would make a big retreat during the back half of the month and a rough 1-2 weeks of skiing was likely state-wide. The actual weather played its own little tune however, improvising quite a bit and deviating verses many of the expectations put forth early in the month. The January 12th event was some seriously bad improv. A combination of features in the jet stream conspired to produce an absolute worst case scenario for New England skiing. This combination included a somewhat phased amplified jet stream across the high plains and a resilient upper air low pressure center over Florida. The surge of warmth across New England was simply overwhelming and was accompanied by rain, high winds and temperatures well into the 50's. The 24-plus hours of all this was simply too much or much of the snow pack, even across the high country. Yes we retained a minimal amount of snow when the snow and sleet returned by Saturday the 13th (MLK weekend) but it wasn't much and thus the Vermont "frozen hellscape" as one follower of the blog called it had officially commenced. 

The improvisation actually continued for another week in January, as arctic cold made an impressive southward surge thanks to the formation of a powerful ridge in the jet stream which took up a position over the Canadian Rockies. The surprisingly strong outbreak of widespread cold provided a golden opportunity for a quick recovery but all of the precipitation and specifically snow was confined to areas well, well to the regions south or well offshore.  And then the cold finally did retreat as the MJO cycled out of the more favorable phases allowing the jet stream to tighten and the infamous "evil empire" to set up shop north and east of Hawaii. January ended quite horribly with lots of mild weather, mixed precipitation or rain and only isolated days of colder weather that included little if any snowfall. Hope came alive toward the end of the month in the form of what appeared to be a much improved weather pattern in February, but the weather continued to improvise and prognosticators that opted to marry themselves to specific ideas regarding the February weather pattern were taken to the woodshed yet again.

February indeed started promising and included both new snow and colder weather. Man it looked good too, especially for those weather enthusiasts that love to hyper focus on the MJO which I can tell you from experience is not running in short supply right now. The MJO had, as expected, move into some of the mild phases in the cycle during the latter part of January but was proceeding very quickly and a 3 year old could have quite easily extropolated that the MJO was riding toward glory in February. Extrapolating the MJO is a dangerous game however, about as dangerous as over-emphasizing the cycle as the single best determinant for the ambient North American weather pattern. Everything was on track initially with snow falling late on Superbowl Sunday and then a foot of snow falling during the middle of the week from a garden variety system that tracked beautifully for interior New England. It all fell apart thereafter however. The MJO stalled, the ridge in the jet stream across western North America fell apart and it finally started to snow across Colorado which had been barren for the entire season. It began to get mild across Vermont by the weekend of the 10th and 11th and then it got milder and then even milder. We got some rain, we lost some snow and then we got more rain and lost more snow. Then the mountains got 60-degree weather on February 21st and many places at 2000 feet had little if any snow. By the end of the month it appeared hopeless. Though improvements were right around the corner, the snow was almost entirely gone below 3000 feet. Pictures taken at Mad River Glen on April 30th show more snow on the mountain verses what was present during the last few days of February. It was a truly depressing state of affairs
  
Morale always takes a beating during blowtorches and meltdowns and in recent years it has been accompanied by doom, gloom and despair. Each round of anomalous warmth always brings discussion of global warming/climate change and comments are often suggestive that winters are "going, going gone" as are decent ski seasons. All of this is actually true if the warming experienced over the last 150 years persists for another 200 years or beyond. Generations from now, winters in Vermont might be unrecognizable compared to what we are typically accustomed. We as a globe have to make it a priority to rethink our carbon footprint if we are to conquer this challenge. All that said, global land and sea temperatures have moved up about one or two hundreths of a degree F every year. Speaking strictly in the scales of geological time, these are alarming changes. They are not changes however that can be easily separated from typical statistical noise associated with variability which as we all know occurs through time and across geographical space. Cold happens, warm happens, storms happen, drought happens and all these things will continue to happen regardless of climate changes. Attributing each anomalous weather event to global warming and climate change introduces some sketchy science unless compelling scientific and data driven arguments are made to support such assertions.  Hurricane season seems to bring out some of the worst actors in this regard. Though warmer water temperatures undoubtedly support stronger storms the available data has not suggested that hurricane activity in a general sense has increased at least during the satellite era. The climate change/global warming issue is a vital one that requires a mass movement just for general awareness. Like any movement of this scale and importance, there are going to be bad actors that rely too heavily on bad science or are simply using the platform to garner attention for themselves. If you are one that tends to be disinclined to take the climate change issue seriously because of characters like Al Gore (who I don't consider the worst actor but is still guilty of using reaching scientific arguments to make his case) I would try and move past it and understand that although some of the alarmists might be seriously wrong about their claims, one still has be extremely concerned about what the climate might look like 100, 200 or 300 years from now. 

One glaring, completely non-sensationalistic example of some early manifestations of climate change is the ongoings across the Arctic and specifically Barrow AK. Barrow, also going by the more indigenous name of Utqiagvic is considered, by some, to be one of the oldest inhabited towns in the United States, sitting at the northern most point of Alaska bordering the Beaufort sea and the vast but rapidly decreasing plate of arctic sea ice. Barrow is a place of -80 degree wind chills with an economy that is geared toward local oil exploration or feeding itself through whaling, fishing or hunting. The town, which remains majority indigenous is a place where memories are stored and past forward over multiple generations and where changes in the climate have real impacts on daily life. And it would be difficult to find a place anywhere in the world where those changes have been as dramatic. The autumn months in particular have been running warm and the weather was so incredibly anomalous during the last few months of 2017 that a statistical algorithm automatically flagged the data and tossed it out of the global aggregation. A more detailed narration of this occurrence can be found in the write-up by Angela Fritz of the Capital Weather Gang in December. 
 
 
In a span of just 20 years a typical October has warmed almost 8 degrees F, almost 7 degrees in November and almost 5 in December. The warming, especially at this latitude is a direct result of climate change and on multiple fronts. Almost every month has experienced at least 1-2 degrees of warming but the autumn months have been especially dramatic because of the dramatic loss of sea ice. 50 years ago, the arctic would usually freeze by October and is now remaining unfrozen through part of November. Barrow has literally become a maritime climate for two additional months. Though there are several visible signs of what has already occured, Barrow stands out to me as being one of the most glaring.

Back to Vermont and the incredible "don't call it a comeback" (yet it really was) month of March 2018.  The month rolled in with the snow mostly obliterated and MRG looking at “practice slope” only conditions and Stowe was forced to cancel their annual cross country derby for the third year in a row. Once again, a Hail Mary was needed to extend the season in any material way.

The pattern looked promising even as the February torch was annihilating what was left of our snow. The pattern change was triggered by the formation of an intense block in the jet stream over Greenland to go along with a negative Arctic Oscillation (AO). Interestingly, there was no available mechanism in the jet stream to transport significant amounts of cold in New England so that hope was that the pattern would deliver simply through sheer storminess and deliver it did. Big storms impacted the northeast on March 2nd, 7th-8th, 13th-14th and 21st-22nd. Not all of these big weather systems impacted northern Vermont; in fact, MRG was hardly the best spot, but during this crazy March, one didn't even need to be in the best spot. The first storm on March 2nd was the most impressive meteorologically speaking, causing wind damage and power outages along with producing heavy wet snow. Most of the snow missed northern Vermont, smacking the Catskills instead with 2-3 feet and delivering a foot to southern Vermont. Mad River did better from the subsequent storm on March 8th and though the storm was notable for the intense 5 inch an hour band that smacked suburban New Jersey, General Stark was back in business to the 1-3 feet that fell by Friday March 9. 

15-30 inches were back on the ground and March 13th had yet to arrive ! Our recent propensity for recording big storms around that date was further ironed into Mad River Glen tradition this year when for the 2nd straight year our best storm smacked the mountain. Though certainly not the strongest system to impact the northeast that month, the set up was absolutely perfect with the block across the Davis Strait prohibiting the storm from a clean getaway and allowing for continuous snowfall for roughly 60 hours. From virtually nothing to some of the deepest snow since 2015, March of 2018 was one of the more remarkable turnarounds. Vermont mostly missed the next big east coast system on March 21st and then received some mixed precipitation and rain during the last few days of the month.


As snowy as March of 2018 turned out to be, it was not especially cold. Temperatures averaged out to about normal during the month and bitterly cold arctic air never really became a big part of the equation. All of this changed ironically when April came around. The blocking in Greenland disappeared and eventually reemerged in a rather substantial way over Alaska and within a few days, extreme cold began making big hard charges southward. Temperatures averaged 7 degrees below normal for the month and when all the numbers are tallied, it will likely rank as one of the 10 coldest April's on record. One would have thought that with all that cold in April, the snow would also fall in abundance. Though enough snow did fall to bring the seasonal total up past 200 inches, the total for the month was actually a little disappointing and only in the vicinity of 10-15 inches or so. Much of the snow that fell in March however, continued to remain on the ground through most of April. As of early May, snow remains across the high country and the growing season is only finally readying itself to commence for the year. 

In the end 2018 managed to provide a little of everything. Though the snow season and Sugarbush ski season extended to nearly 6 months, February has to stick in one's craw. The traditional peak of the Vermont ski season was torched away by warmth while especially intense bouts of winter in varying forms ravaged Vermont both prior to and after February. The season was decidedly colder than the previous two, accompanied by either normal or below normal temperatures in November, December, January, March and April. There was plenty of snow across the northeast as well, but northern Vermont simply was not in the best place for it. The over 200 inches recorded by the end of April is within the vicinity of normal but a vast area beginning not far to our south recorded well above normal snowfall. Compared to normal, here is a breakdown of how certain regions did surrounding Vermont. 

Southern Vermont: 125-175 % of normal 
Coastal New England: 125-175 % of normal
Maine: 100-150 % of normal 
NYC/The Catskills/The Poconos/Jersey: 150-250 % of normal
Mid Atlantic Region: 75-125 % of normal 
CentralAppalachian (PA/WV) 125-175 % of normal
Southern Snow Belts: 150-250 % of normal
Northern Snow Belts: 75-115 % of normal

Northern Vermont in regards to snowfall was actually on the eastern edge of a broad area that extended through the Upper Peninsula of Michigan that under performed relative to their southern counterparts. In the case of Mad River Glen, it was simply being too far northwest for the most intense areas of precipitation. It seemed as if almost every storm got the mountain a little but only a select few got the mountain a lot even though we had so much winter to play with. It's all apart of the history books now and hopefully most that follow the blog got a chance to play in it a bunch. Enjoyed the effort once again as always and will be talking winter once again on the other side of the upcoming summer.