El Niño: Early ski season success for the Pacific northwest
Wednesday, November 18, 2015, 6:37 PM - As of November 18, many B.C. -- and some Washington, Oregon, and Montana State -- ski resorts are dealing with an abundance of the white stuff, especially when compared to years past.
Don't believe me?
Take a look for yourself. First we'll look at the Canadian ski hills:
Don't fret if your beloved local ski hill wasn't listed. Either they're not reporting data before the ski season, or snow totals weren't that impressive yet ... there's still hope.
Snow bases are currently building on Vancouver Island (Mt. Washington) and all the North Shore ski resorts. In fact, Seymour Mountain near Vancouver, B.C. will be opening up this weekend.
Naturally, the regions above have some of the highest avalanche danger ratings in North America. Skiers, it's advisable to be cognizant of these very real risks, as heavy snow paired with early season fluctuating freezing levels is a perfect recipe for unstable conditions in the alpine.
Washington State has had some mixed success as a couple early season atmospheric rivers have aligned perfectly with the Olympic and Cascade mountains. Unfortunately, this has brought a double-edged sword.
The precipitation from the recent atmospheric rivers tended to bring higher snow levels and more of a warm, moist southwest flow aloft; consequently, the snow bases are a little more modest when compared to British Columbia. Nevertheless, snow is accumulating in Washington, Oregon, and Montana with many resorts poised for a December opening.
You want proof?
Is this really an excellent start to the ski season? First, we must compare to the previous abysmal ski seasons to really see the glaring differences.
Satellite, ground, and myraid of other observations can give us a concrete idea of what the snowpack looks like. The National Snow Analyses (NSA) is a complex algorithm that takes these numerous observations and creates a virtual snowpack (see below).
The date chosen: November 18, 2015
[Upper left 2012, upper right 2013, bottom left 2014, bottom right 2015].
So it's official. This is the greatest start to the ski season in years.
In fact, it's the best since 2011 for some in the Pacific northwest.
So what's the deal?
Isn't El Niño usually responsible for less-than-normal snowfall totals in the alpine, paired with above-normal temperatures?
Yeah, but every El Niño is unique, almost like a fingerprint.
Currently, El Niño and sea surface temperature anomalies will give us some clues about some of the unique features of the current El Niño conditions and what sets it apart from the rest.
As you can see, the darkest reds above show the warmest waters remaining well off the coast of South America. Note the especially warm waters west of 120° with some of the warmer anomalies extending out to 180° east; this is much further west when compared to our last major El Niño in 1997-1998 which had the pool of well above average temperatures hugging the South American coastline.
These subtle differences will likely have major implications as we head into the next few months.
The influence of these warm waters can not be understated.
They have the potential shift our troughs, ridges and overall weather pattern — one of the main drivers of the larger scale pattern as we head into winter 2015-2016.
Question: Why has the ski season been so poor for the past several years?
Answer: The mega-ridge, a.k.a. the ridiculous resilient ridge
This type of atmospheric pattern sends shivers along the spine many skiers and mountaineers.
Over the past several years, the B.C. ski season has had short bursts of success, but generally has been inadequate at sustaining excellent conditions. This persistent ridging has looked like this.
Unfortunately, it's unlikely our Pacific jet stream will remain in such a hyper-active state, like witnessed the past several weeks.
Another critical note — November rarely dictates and drives the rest of the winter pattern.
Past El Niño events at Whistler, B.C.
[Average seasonal snowfall: 1,164 cm]
* Denotes a strong El Niño
Don't panic, although typically, an El Niño will bring less snow than normal, it's typically not substantially less.
The two recent strongest El Niño's are 1982 and 1997. Subsequently, they had less in the way for snowfall (10-20% below typical average snowpack) and may be a fairly good proxy of what to expect for 2015-2016.
Long range models show conflicting solutions on where the main ridges and troughs will tend to anchor in as we head into 2016.
So far through November, we've been in a very atypical El Niño pattern with ridging northeast of Hawaii, which has helped steer the needed moisture to create snow into the Pacific Northwest.
Current thinking suggests that this will be replaced by a trough-like pattern north of Hawaii, and less persistent troughing along the west coast as a more typical El Niño pattern takes hold.
This is not to say there won't be periods of active weather along the coast with high elevation snowfall, but generally speaking a trend will start emerge in December. There's also signals that after our strong El Niño, we'll trend towards a La Niña next ski season which generally speaking, brings excellent skiing conditions to the Pacific Northwest with above average snowfall. These are some of the parameters and thoughts that go into creating a winter forecast.
Tune in on November 30th to The Weather Network for our exclusive look at the Winter 2015-2016 seasonal forecast. For a little extra luck, pray to the snow gods for a ridge-free B.C.