Weather nerds: school me on where snow comes from

[onstar]

I was just thinking, where does the snow fronts in Utah and Colorado come from? Tahoe/Sierra gets their snow from the Pacific storms. However, on the other side of the Sierra, Nevada is pretty much dry. This is due to The Sierra blocking most of the moisture. The Tetons gets feed via the Snake River Plain. What systems feeds Colorado and the Utah resorts?

 

[Analisa]

Jet stream doesn’t move just west —> east; it meanders north and south as well, so storm systems can come down from the PNW or Alaska or Canada.

Likewise, storms in the mountain west are a little more complex than, say, an east coast hurricane that makes landfall and eventually peters itself out somewhere along the coastal states. For example, in Washington, air/wind splits north and south around the Olympic Mountains and comes back together in the Puget Sound Convergent Zone. That’s why Granite Falls WA gets 59 inches of rain per year vs 39 inches in Everett, even though they’re only 16 miles apart, and Granite Falls is further east.

 

[onstar1]

Jet stream doesn’t move just west —> east; it meanders north and south as well, so storm systems can come down from the PNW or Alaska or Canada.

Likewise, storms in the mountain west are a little more complex than, say, an east coast hurricane that makes landfall and eventually peters itself out somewhere along the coastal states. For example, in Washington, air/wind splits north and south around the Olympic Mountains and comes back together in the Puget Sound Convergent Zone. That’s why Granite Falls WA gets 59 inches of rain per year vs 39 inches in Everett, even though they’re only 16 miles apart, and Granite Falls is further east.

yes, but whats the usual source for utah and colorado?

 

[dbostedo]

@Jellybeans1000 ??

 

[Mike Rogers]

I was just thinking, where does the snow fronts in Utah and Colorado come from? Tahoe/Sierra gets their snow from the Pacific storms. However, on the other side of the Sierra, Nevada is pretty much dry. This is due to The Sierra blocking most of the moisture. The Tetons gets feed via the Snake River Plain. What systems feeds Colorado and the Utah resorts?

Isn't it still pacific storms? We get most of our season's snow from the Pacific here in Alberta.

In BC there is a desert east of the Coastal Range, but when the systems hit the Columbias orgraphic lift causes snow and rain to fall. It's dry on the other side of the Columbias too (Rocky Mountain Trench), then we get another dump of snow as the system moves over the Rockies.

 

[DoryBreaux]

They come from Ullr.

 

[Wilhelmson]

2017 US radar time lapse. Apologies to those north or south of the 48.

 

[slowrider]

When a Polar Vortex collides with a Pineapple Express look out. ;-)

 

[Lorenzzo]

Yeah there are supposed science explanations. The plain reality is snowfall reults from the whim of Uhlrhr. He evaluates spot kharma in a given place and then distributes snow accordingly.

Sure...the jetstream...lol.

 

[Lauren]

 

[crgildart]

They come from Ullr.

 

[tball]

Don't forget the importance of orographic lifting in creating mountain precipitation.

 

[surfacehoar]

If the wind has enough energy to push up and over the Sierra it does just that. This results in an air mass traveling down the slope and being stretched out. The moisture doesn't condense and travels over the desert before reaching the next mountain range in it's path.

 

[Core2]

Yeah there are supposed science explanations. The plain reality is snowfall reults from the whim of Uhlrhr. He evaluates spot kharma in a given place and then distributes snow accordingly.

Sure...the jetstream...lol.

I believe this is true also and that Vail is making some sort of sacrifices to him so that their resorts continue to remain viable. I'm thinking it likely they sacrifice one or two lifties per resort each season so that it keeps snowing.

 

[HardDaysNight]

I doubt Ullr would consider lifties an adequate sacrifice. He appears to be a tough dude, much given to dueling and archery. Despite the common misconception he is not the god of snow although he does appear in Norse depictions holding a bow and wearing skis. Perhaps he’s the world’s first biathlete!

The goddess of snow is Khione, daughter of Boreas and a cold customer.

 

[Analisa]

yes, but whats the usual source for utah and colorado?

There's a lot of nuance based on the area, wind speed, wind patterns that fluctuate. But generally, winds carry air & vapors. When they hit the mountains, they rise, it's colder in the atmosphere, and cold air doesn't have the capacity to hold water vapor the way warm air does. Winds can also move around mountains into convergence zones like the other example.

If storms cross the Sierras, on the other side, there might be a desert, but there's still water vapor in the air. It's just a) the storm already deposited a lot of water vapor the clouds didn't hold on the mountain and b) vapors that are left are able to move lower in the atmosphere where they're warmer. Even if they move straight west towards CO and UT, evaporation over the dry areas will continue to add to those clouds and they'll be thrust over & around mountains again, creating additional storms.

 

[Lorenzzo]

I doubt Ullr would consider lifties an adequate sacrifice. He appears to be a tough dude, much given to dueling and archery. Despite the common misconception he is not the god of snow although he does appear in Norse depictions holding a bow and wearing skis. Perhaps he’s the world’s first biathlete!

The goddess of snow is Khione, daughter of Boreas and a cold customer.

Whoever he is...there's mounting evidence he purchased an Ikon pass.

 

[HardDaysNight]

Whoever he is...there's mounting evidence he purchased an Ikon pass.

Well I mean who wouldn’t! Smart chaps these nasty Norse gods.

 

[Lorenzzo]

As I've waifed from Tahoe to Mammoth, Park City to the Wyoming Tetons, I've learned to ignore forecasts. Weather forecasters have the science, they know where snow comes from, they just don't have real ability to predict. It's like fantasy weather, akin to any fantasy sport where we take what we know and guess to be right but are usually wrong.

There is however one source I've learned to follow. When they have something to say I tune in. At each of the above places there's been group of folks in their 70-s or even 80-s who've been around mountain weather in their locale for a very long time. Within that group are one or two who have this ability to add things up and produce a forecast based on little science rather experience and keen observation. They see storms that aren't in the forecast that bear out. They guffaw at big forecasts they know will crumble.

One example is next week in the Tetons. Forecasters, the models, open snow, etc. haven't been showing anything significant. These guys are saying get ready.

 

[Snowfan]

Need both a disturbance and a moisture source. They don't always travel together.