Winter 2021/22 - Advance Weather Forecast Factors

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Winter 2021/22 - Advance Weather Forecast Factors

Post by T360 »

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It’s Time To Seriously Start Thinking About Skiing For 2021/22


An Article For Weather Nerds Who Enthusiastically Look Forward To Skiing At Tremblant.

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Welcome to the very first T360 advance posting for the Winter 2021/21
Ski and Snowboard Season. We will be featuring an outlook at weather
factors expected to shape both the foundational snowfall and temp
ranges that will ultimately help define the uniqueness that every new
season evolves to.



National Oceanic And Atmospheric Administration(NOAA)

Advisory Statement:



“La Nina conditions have developed and are expected
to continue with an 87% chance of La Nina in
December 2021 - February 2022.”




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As perpetual optimists, we like to start with a positive outlook
forecast, and in this case, it comes from “AccuWeather”, a highly
trusted source that you will find frequently referenced within
Tremblant360 weather discussions.

If you look at the right side of the graphs below, you will
see that the colour gradient for the Northeast zone that
includes Tremblant, indicates snowfall predictions between
125 and 149 percent above average. That would mathematically
mean roughly 530 to 550 cm’s of seasonal Tremblant snowfall,
compared to the 20 year average which is now just around 420 cm’s.



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Summarized AccuWeather Forecast In Point Form:

For Northeast North America:


- Early arrival for winter.

- Two potential November rounds of cold, snowy
cycles for the Great Lakes/Interior Northeast.

- Mild moderation to winter cold and snow
cycles by mid-December.

- Cold winter cycles return "With a Vengeance"
in January with entrenched cold air masses that
could cause widespread disruptions due to snowstorms.

- The typical "January Thaw" is more likely to be a
"February Thaw”.

-There is some probability of one or more "Polar Vortex"
migration events over central northern Canada at or around
the end of February or the first of March.

- Significant "Lake Effect" snowfall throughout the
Great Lakes basin may occur as a result of water temps
that are as much as 5.5 C/10 F warmer in October 2021,
than they were in October 2020. Prevailing S/W winter
winds could consequently move additional snow toward
Tremblant with either Colorado or Texas low's passing eastward.

- The most important influence in consistent, reliable, increased
snowfall potential for Ontario and Quebec should be the
La Nina-impacted polar jet stream swooping over the eastern
portion of the nation.

-Specifically for Skiers: "Expect a favourable winter with solid
snowfalls across much of ski country in Eastern Canada and
especially Quebec" with warmer than average season temp's by
1 or 2 degrees C.


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T360 Commentary:

The overall similarity to last season is definitely the “La Nina”
system influence, however, what we are hoping for in this new
upcoming season is a difference in the snowfall totals, as last
year’s official total accumulation of 353cm’s was actually less
than average by about 70cm’s. It could be argued that because
the heat came on so consistently towards the latter part of
March, we just never got the typical natural snowfall that
usually comes right through early to mid April. That alone
could completely explain the shortfall.

The saving grace of last season was that even though it was
a relatively mild temp season, we did have an extended number
of sequential sub-zero C days that bumped along sometimes
quite close, but always just below the freezing mark, never really
going over it. Consequently, all the snow that did fall, stayed in
place with almost no thermal intrusions. This wonderful string of
“cool”, basically ran from Boxing Day(Dec.26), until the “Heat”
happened at the end of March.

What that proved was that great conditions can and do happen
even in statistically lower than average snow years when the
reliability of northerly cool weather is uninterrupted by thaw
events and you get to keep everything that falls when those temp’s
remain just cool enough below the freezing point. You can and
should review last seasons pre-season weather outlook as well,
because what the comparison also shows is that a year ago, the
potential for abundant snowfall was in most ways, just the same
as it is now, but for reasons discussed above, the reality tipped
to the low side at the late end of the season.

If you could “Cherry Pick” the ideal combination, it would be both
the extended run of thaw-free sub-zero C days, but with the fully
maximized seasonal snowfall, and that is a distinct possibility with
this AccuWeather forecast. What makes that a likely possibility is
the reference to the combination of the mid-winter “Thaw” to be
in February(*), a naturally very cool month at Tremblant, so it might
not actually be a thaw, just warmer in the sub-zero C range than
normal, followed by the predicted probability of “Polar Vortex” events
in March. These two factors could extend Mother Natures snowmaking
potential with cool temp’s until very late in the winter season.

If you want to see a recent example of a similar initial forecast profile,
but with a reality outcome that did produce an actual 540cm’s “Super Season”
total seasonal snowfall, go back and look at the pre-season weather
predictions for 2017/18 in this forum section and you can see the
parallels to where we could be with this very same starting point we
have today.

(*) February is the third month here of statistically below zero C
daily average winter temps. So, being up temp-wise with what can
regionally be a legitimate thaw to south of Tremblant, can often
mean that at especially at cooler Mountain elevations here, all we see
is warmer than normal, but still within sub-zero ranges. We specifically
highlight this phenomenon because it is a distinct advantage of
northerly latitude where Tremblant has 3 statistical months of sub-zero
(Dec., Jan., Feb.) and for comparison, Vermont now only has one(Jan.).
Our point here is that for consistent “Winter” “Snow” and “Skiing”...
conditions generally benefit from Mother Natures basic sub-zero C
permission.


Below:

With Reference To The Potential Of Great Lakes “Lake Effect” Snowfall:

This is a repeat of a graphic we made for last season that
due to all described similarities to this season’s forecast,
is directly applicable to the potential of this years forecast.


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Otherwise and generally...

Of course... Mother Nature can fool humans without advance notice,
and consequently results may vary, but there is still predictive strength
in probability so the odds are still in our favour.


---------- 10.25.21 Additional Update: -------------

This next weather forecasting source we are adding is “WeatherBELL”.
This is one we consider very significant because it is essentially an
industrial weather forecast outlet that serves largely corporate clients
who need accurate weather insight to plan production or service provision
that is weather dependant for seasonal delivery.

Applied to Ski Areas, we do think you could get a more directly
connected relationship between service provision and weather
dependancy, so obviously any serious students of Ski Area
forecasting would be well advised to include WeatherBell
projections into account.

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Right out of the gate, AccuWeather and WeatherBELL
agree on one of the most significant seasonal advantages,
the very first thing they refer to is “EARLY START TO WINTER”.


The importance of this element can not be overstated. An early start is
one of the very best foundational components for any following weather.
Allowing for early, heavy snowmaking, allowing for early frost into the
Mountains surfaces, and allowing for Mother Natures own natural
snowmaking potential, all rank as quite nearly “Ideal” for establishing
any new ski season. Virtually any form of subsequent weather is very well
tolerated after an early cold start. If it gets warm for a while after the start,
which can happen because technically, it’s still “Fall” until Dec. 21, the
resiliency of conditions is greatly improved. If it gets colder(preferred),
after the start, typically, there’s more natural snow, snowmaking can
increase, so the overall rate of general trail development accelerates at
much quicker rate. This would be fantastic news for Christmas and New
Years Holiday planners, not to mention the benefits for long term seasonal
expansion.

In our commentary following the AccuWeather forecast we pointed
out that you should review the forecast we made for 2017-18 as it
is a similar predictive profile to what seems to be developing this year.
So, we were very encouraged to see that WeatherBell also includes 2017-18
as one of their “Analogue Years” because: a) it is recent enough that Global
Warming as a singular component of the overall mix is far more relevant
than data from the mid-to-late 20th Century, b) it produced near 540 cm’s
of natural snow compared to the 25 year average of 420 cm's. Still more
proof that we can have a solidly cool and abundantly snowy winter season
even as the planet is undergoing change.

As usual, not everyone agrees with all the exact detail, so while WeatherBELL
characterizes February as “Brutal”, we should be reminded that AccuWeather
thinks the typical January thaw is more likely to be a February thaw. As a device
to extend the durability of each and every ski season, we will take all the cold
Mother Nature is prepared to send, for as long as she will send it.

What we see after over 4 decades at Tremblant is that all, but especially
spring trail surface quality and coverage is directly related to residual
cold embedded into the conical mass of the Mountain and every cm/inch
of frost penetration in the granite core of Tremblant is stored for time
release when the Spring sun arrives, so more/deeper frost literally means
more base and more skiing. For that one reason we are happy to see any
and all of these factors that can positively enhance the qualities of winter.

In that sense, we favour the WeatherBell difference of opinion on their
forecasted temp ranges which they are calling for a degree cooler than
average, compared to AccuWeather calling for a degree warmer. You might
not think that could be possibly important, but if you looked at the number
of days last season we stayed under zero C by a degree, averting thaw,
you’d realize just how critical that could be.



O.K., Here’s A Main Feature For 2021/22 Tremblant Skiing Weather Nerds:


Earth is a sphere, it spins, and the weather above its surface is affected
by many rotational forces and patterns that are consequently intertwined, so...



"What Goes Around, Comes Around"



Global weather models generated by European forecasting sources
have always been components of T360 Fall reviews.


The following 2 graphics may well exceed the average weather bugs desire
for information, however, it directly ties into many aspects of all currently
available advance forecasting models for Eastern North America Winter 2021/22.


Zoom-In For Detail If Necessary.



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One of our pet peeves in any technical writing is that articles contain
short forms/acronyms/initialisms that are not explained, making the
articles very difficult to comprehend or understand. For some examples,
points # 5, 6 and 7 in the above graphic contain “NAO”, “MJO”, and “QBO”
without definition, so we are including the graphic below to add explanation.
The reference “SSW”, initially in point #4 above, is explained in point #8 above.

Otherwise, for other short forms you can’t find definitions for in graphics,
if you Google the term with the word “Weather” in front of it, you will likely
get the meaning definition you need.




10.16.21.MKWeather.Winter.21.22.North.American.Forecast.Supplementary.Glossary.Definition.Data.a.jpg
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We are not forecasters, so instead what we look for is consensus amongst
the highest profession levels of actual forecasters, and the more consensus
there is on any single forecast element, across the various predictions available,
the greater the probability or likelihood may be for that element to evolve to
reality? By looking at all the forecasts included in this T360 topic you can begin
to see where there are both similarities and differences. Of all the similarities,
two are the most desirable and important... 1) An early start, and 2) loads of snow.

Beyond these two major fundamentals, there is a wide range of forecast
possibility across the range of predictions, such as the likelihood of either
a February thaw or a brutally cold February, a mid-winter average of 1 or
2 degrees C above average, or a 1 or 2 degrees C mid-winter below average,
etc., etc.. We can only come back to what we consider to be the default asset
for Tremblant Winter weather that is the very basic benefit of a Northerly
latitude that statistically generates 3 months a year of sub-zero C average
daily temps.



NOAA

No Eastern North American weather forecast would be complete
without a NOAA(National Oceanic and Atmospheric Administration/U.S.Gov.)
forecast component.

It should be noted that the following charts for temperatures and
precipitation are only for percentages(%) above or below normal ranges,
so it does not mean we are going to see “Hot” or “Rain”, just likely above
normal range values, which at Tremblant in Dec., Jan., and Feb., would still
be cool winter anywhere else.



11.18.21.NOAA.Winter.2021.22.Temp.Precip.Probability.Data.a.jpg
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The important point to remember about “warmer than normal” at Tremblant
in mid-winter is that it could actually put the Mountain into Mother Natures
own, best natural snowmaking temperatures more often. If you combine that
with the above normal chances of precipitation, it could all add up to a really
easy, super snowy winter.

Of course we could be wrong, but recent winters like 2017-18 have clearly
shown it is very possible.




We have to report an anomaly in our regular winter forecast sources.
Canada’s own “The Weather Network” has, as of mid-November, not
produced a winter forecast for the very first time we can ever remember
or think of. Very, very odd, and we’re not sure why. We have written the
network but received no reply.

The one related graphic that is still very important due to the impact
weather always has when the season is just beginning, is included below.


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In order to form a more complete outlook we will be including additional
forecast sources here in this topic in order to render out a composite
overall summary, so please stay tuned for those to follow.





Lore, Legend, and Learnings.


The historic perspectives and forecast highlights of the two most
prominent Almanac style annual weather forecasting sources.



It could be theorized that in terms of individual forecast
elements, the Old Farmers Almanac(second below), may
have more directly applicable, specifically identifiable
winter characteristics.



The Canadian Farmers Almanac:


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The Old Farmers Almanac:


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One of the main take-aways from this article should be the planning
confidence readers can sense from solid weather indications of good
“Winter” potential for purposes of early bookings for mid-season Ski
holidays. What we like to see from forecast sources is consensus.

Of course(a): no one can guaranty exactly what Mother Nature will do,
but based on as many factors as we can gather, the odd’s for a great
winter ski season have a very high degree of probability.




Of course(b)... The real “Proof Of Value” in any forecasting process is
the unfolding reality as it occurs. Does actual experience match up
with the projections, and if so, to what degree?

For the “forecast vs. actual” comparison, the benefit for Tremblant360
readers is that you can ultimately watch that unfold by following along
with the daily evolution of open ski season conditions within the “Mountain
Conditions” journal for the 2021/2022 winter season at:




GoTo: Archive, Search Reports by Date: Index: http://tinyurl.com/yktelmu



What’s The Use? Research Benefits of the Tremblant360 Archives: http://tinyurl.com/gp5vjps



.
The Tremblant360.com Team