Fernie Factor

With this recent spate of warm temperatures and little snow, the weather has been top of mind. While we don’t have a definite answer of when the next (needed) dump will be, there has recently been an in-depth paper published by Michael Conlan and James Floyer, that just might help us to predict when the “Fernie Factor” will occur. 

The Fernie Factor refers to the tendency for us to receive more snow than forecasted. According to meteorologist Ron Lakeman (FAR Mountain Weather Forecaster), this happens for a couple of reasons. 
1. The collision of two prevailing weather patterns, pacific low-pressure and arctic high-pressure systems. 2. The intricacies of British Columbia’s and Alberta’s geography dictate how these patterns manifest on the ground in any given spot.

Due to the process of orographic lift, we can think of the mountain ranges of BC as acting like a “filter.” They strain the water out of the air as coastal fronts travel over them. This means the Rockies receive less precipitation from these systems. Fernie, however, is an exception! The geography to the southwest of Fernie has a relatively low elevation allowing unimpeded passage of pacific systems. The Rockies also provide a barrier, pushing the Northern cold fronts through Crowsnest Pass into BC. When these fronts collide with the wet air over Fernie, we receive unexpectedly high precipitation events!

We can thank Michael Conlan and James Floyer for further exploring why we often receive more snow than predicted. Conlan and Floyer (2023), who presented their findings at the International Snow Science Workshop, analyzed local weather data from 2017-2023 and observed a pattern of additional variables occurring during Fernie Factor events. Through their advanced research they were able to determine that when the following factors are present, chances are we may receive more snow than predicted. 

Factors:

1. Wind speeds above at least 40km/h at an elevation of 2000-3000 meters.
2. Low pressure system tracking over the Lizard Range.
3. Temperature of -5℃ at an elevation of ≅ 1600m (which often corresponds to a freezing level at 1000m (Fernie’s elevation)!

It’s interesting to note that when the last factor is in effect, the snow-liquid ratio is often higher, which equates to lighter snow. Another notable finding was that snowfall amounts were similar across the three locations (FAR, FWA, ILL) where Conlan and Floyer collected their data. 

Also of note, these researchers found that the Fernie Factor occurs within a 15km radius; we truly are lucky that we live in this unique town. 

So, how might we predict when the forecasters might underestimate precipitation? Firstly, a southwesterly low-pressure front reaching Fernie. Secondly, check Avalanche Canada’s Mountain Weather, to confirm a cold, northerly high-pressure front. Finally, check VentuSky.com to see if there is a high wind speed at 2000-3000m. If it’s freezing in town, there’s a good chance it’s -5℃ or colder at 1600m. 

If all these variables are lining up, it might be time to call in sick! Feeling confident in your predictions? Head over to the Fernie Fix Facebook page and see if you can predict if the next storm will be a Fernie Factor event.

 
Reference: Conlan, M., & Floyer, J. (2023).  Enhanced Winter Precipitation Near Fernie, British Columbia. Proceedings, International Snow Science Workshop, Bend, Oregon, 2023. 
 
Photo by Christian Wilson
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