Photo courtesy Idarado Media – Opening Day November 23rd

 

Pre-Season Snow Roundup

Current snow depths in the Sawtooth Mountains are running well-above normal. Here are a few readings from NRCS SNOTEL sites nearby:

Site                                  Snow Depth           % of Normal

Jackson Peak                   17”                         206%

Vienna Mine                      22”                         152%

Galena Summit                 17”                         189%

Overall, across the area that includes Sun Valley, here’s how it’s stacking up compared to “normal” which spans a period from 1981-2010. We’re on the upswing and that is likely to continue the next few months (spoiler-alert).

Last year at this time there was very little coverage in the Sawtooth Mountains near Sun Valley.  This year is a much different story. Even though October was a very dry month compared to last year, we have made up for lost time in the past few weeks. Take a look below at the seasonal snow depth for today, compared to November 11, 2016. Blue colors generally represent high elevation snow depths of 20 to 30 inches, while brown and green colors are dry ground.    

Snow depth comparison November 11, 2017 (left)  to 1 year ago (right). Darkest blue colors represent snow depth up to 20 inches. Courtesy NOAA OWP

 

Now for fun, let’s look at a time lapse of the snow depth so far this season:

 

Short Term Forecast

This Week

The feature that will drive our weather this week is the dark black trough located off the West coast in the satellite picture below. This is a water vapor picture taken from space that indicates areas with the highest moisture content in dark blue. Note the storm that moved through us last night with about 4" of snow is now in Southwest Montana.

GOES-West Water Vapor Satellite Imagery, Courtesy NOAA

 

Expect a series of 3 separate storms to affect Sun Valley this week.  A wimpy system Monday will bring a few inches to the highest peaks, another mid-week storm on Wednesday and Thursday with a few more inches, then a longer-lived, but high-elevation event from Thursday through next weekend. With the mid-week storm, we expect to see snow down in the Wood River Valley, with snow levels between 3,000 and 4,000 feet.

Snowshoeing and Nordic skiing on the trail system will help you dust off your ski legs for things to come. Also be sure to mark your calendar for the movie at Sun Valley Opera House Wednesday, November 22^nd – just in time for first chair of the year.

Photo Courtesy Idaho State Parks and Recreation

Here’s a preview of how much accumulation is expected through the next 7 days. Overall, I anticipate another 6 to 8” or so piling up this week, which will about double the natural snowpack that we have now at mid-slope elevations:

GFS Computer 7 Day Modeled Forecast Accumulated Snowfall through Saturday

 

Sunday, November 19 through Thanksgiving (Opening Day)

More of the same is expected for the next 8 to 14 days as another strong trough of low pressure will be positioned off the coast to drive in periods of precipitation and near normal temperatures. Here’s the way it looks in terms of the upper atmospheric pattern according to an ensemble approach. That means we take several computer models and combine their solutions to get an overall feel for what is in store as we head toward opening day.

GEFS (ensemble) 5-day Forecast – Notice the deep trough extending from the West coast all the way through Alaska (in Blue and Purple)

 

The Bigger Picture Winter Outlook – La Nina is here!

As expected, this week NOAA issued a La Nina Advisory based on conditions shaping up to bring us cooler and wetter conditions this season.  Take a look at a few of the graphics below for a big picture of where Sun Valley lies in terms of probabilities compared to other seasons with more than 20 La Nina winters since 1950. Note that the average position of the Polar Jet Stream (in Dark BLUE) is just about right over us. It’s also important to note that WEAK La Nina events have statistically favored higher snow seasons for us, and this is expected to do the same. I hope you got your season pass already, hint/wink!

Thank you for Reading. I hope that you are amped for the upcoming season like I am.

My next forecast update will be next weekend, prior to opening day on Thanksgiving, with daily Sun Valley forecasts through the rest of the season.

 

Coleen

Wednesday, November 22 7 pm Matchstick Productions Premier ski movie

“Drop Everything” – Sun Valley Opera House

https://www.sunvalley.com/things-to-do/events-calendar

 

Thursday, November 23 Sun Valley opening day – 82^nd Season!

https://www.sunvalley.com/

 

Countdown to the Winter Olympics - Beginning February 9, 2018

At least 3 Idaho athletes are vying to compete in the Winter Games in skiing and snowboarding events. Stay tuned for more information or check out the website

https://www.olympic.org/pyeongchang-2018