Winds & Lift Operations at Squaw

Category: Operations Blog

Determining Factors that Guide Operational Decisions

We are a unique ski resort in that many of our coveted chairlifts are situated on the Sierra Crest and can be greatly impacted by winds when storms roll through. This season has been, quite literally, like no other winter season in the sixty-plus years ski resorts have been operating in the Sierra.  In a region known for big snow storms, this has been a record season on snowfall, year-to-date, and wind. While we seek to run all chairlifts at all times, we cannot compromise safety. And while the snowfall has presented the region and all ski resorts plenty of challenges, the wind has been prohibitively fierce and doesn’t allow us to run, at times, chairlifts safely. 

Top 5 Factor Checklist to Open or Close Chairlifts

As told by Chris Woo, Director of Lift Maintenance at Squaw Valley

  1. Anemometer Readings & Physical Testing: "First, we look at anemometers. If it is reporting 120mph we're not even going to try and move lifts, for obvious reasons. If it's saying 20-50mph we're going to to go up to the chairlift, run it and see what it looks like." 
  2. Wind speed & Direction: "We use wind direction and intensity to determine whether a lift can operate or not." Check out our lift & wind "vulnerability" chart below. 
  3. Chair Swing: "Majority of the decisions to operate is based on the chair swing. It's actually the basis of our decision to run a chair. There is an approved "chair swing" by the manufacturer, meaning how much the chair can swing front to back and side to side to safely operate. We look at how the chair reacts in the wind."
  4. Wind Frequency: "Gusty winds are bad because it pushes and creates more turbulence while increasing chair swing. Consistent or steady winds in moderation are typically more predictable and may be sometimes better conditions to operate. Although, even steady consistent high winds will often prevent a safe operating condition."
  5. Forecast: "We always look at the forecast provided by the National Weather Service. If we're at pretty high winds already in the morning and the forecast is calling for winds to increase throughout the day, we might consider closing that lift. However, if we're at marginal winds and the forecast is showing winds to decrease, we will wait and watch to see if we can open that lift and put it on 'wind hold'." ​

Wind Speeds Season to Date

Crest Winds vs. Base Area Winds

While winds can be 20 – 30 mph at the base, they have been frequently blowing at three to six times that speed across the middle and upper parts of the mountain.  This has been a remarkably consistent circumstance over the past two months. This graph shows the significant difference of wind speed at different elevations season to date. 

 

Lift & Wind Breakdown

"All wind in excess is bad. We use wind direction and intensity to determine whether a lift can operate or not. Lift design and top terminal location also plays into the decision. For instance, a 6 pack chair with a lower lift profile (more towers, closer to the ground) will typically perform better in windy conditions. That being said, just because we see a wind speed of “x mph” does not necessarily guarantee opening a lift. Another thing we have to consider is the wind direction. It is not always consistent across the entire mountain. For example, we have placed wind socks on the upper mountain to where on a clear windy day, at the top of the Funitel, you can see multiple locations simultaneously blowing in different directions. It is not unusual to have every wind sock identifying a different wind direction."

- Chris Woo, Director of Lift Maintenance

Squaw Valley's lifts broken out to show level of “vulnerability” to wind closure 

Group A: Most affected by winds due to top terminal location
  Wind Direction That Negatively Impacts Operations
Headwall SW, S, W
Siberia E, SW, SE
Emigrant E, SW, SE
Broken Arrow E, W
Group B: Affected by winds, but not as sensitive as group A
  Wind Direction That Negatively Impacts Operations
Solitude E,W
Squaw One W, N, S
Big Blue N, S, SW, SE
Belmont N, S, SW, SE
Tram W, SW, N
Silverado N.S
Granite E, S (limited by access from Shirley. No Shirley, no Granite)
Group C: Affected by winds, but not as sensitive as Group A & B
  Wind Direction That Negatively Impacts Operations
Bailey's Beach W, E
Mountain Meadow N, S, NE, NW, SE, SW
Shirley W, NW, E, NE, S, SE, SW
Olympic Lady SE, SW
Gold Coast N, S
The Pulley  
Group D: Likely to run on storm days, but affected by wind speed and direction
  Wind Direction That Negatively Impacts Operations
KT-22 SW
Funitel  
Group E: Most likely to run on high winds days
  Wind Direction That Negatively Impacts Operations
Red Dog W, SW
Squaw Creek W, SW
Far East S, W
Exhibition S, W
First Venture  W, SW
Analysis of Headwall Operations in January & February 2017

To better illustrate how winds and snow impact our lift operations an analysis of Headwall lift operations from January and February is presented below. Headwall was chosen due to its high impact on skier flow, quality of skiing and upper terminal proximity to the Siberia anemometer.  All of the data utilized in the preparation of this analysis is available publicly through our snowfall tracker, daily lift operation reports and anemometers (see resources tab).

For the purpose of the analysis provided, maximum wind gust for operations was set at 50mph, which is set by the lift manufacturer, and coming from the S, SW and W directions.

Key Takeaway

Outside of significant snowfall days, dig out days and wind days (as described) Headwall lift operated every day that conditions allowed for safe operations. Additionally, for further research on specific days conditions, links to each ops blog post have been provided below.