Western US snowfall

[Cannatonic]

Checking around the 'net today I see that Mammoth has officially broken its single season record - most snow since record-keeping began in 1969 - 340 inch base at the summit!!!! Jackson Hole and Grand Targhee both at 145". Alta 218" base at the summit....yippee!!!

https://www.mammothmountain.com/on-the- ... ly-message

https://www.seattletimes.com/nation-wor ... ke-a-word/

[Montana St Alum]

Alta, 823" today for the season. 30-50" in the next 2 to 3 days.

We need the water, but damn, I'd like to get in some mountain biking at SOME point!

[spopepro]

I now feel bad about telling @@jyw5 not to come to lassen this year in June. Turns out this would have been the year...

I think the most interesting thing is not only the quantity of snow inches, but the water equivalent too. Last year we got close to 100% of median snowfall in many places:


However, no where near median water. Here's the snow water equivalent chart with the median, this year, and last year plotted for the snow lab near tahoe:

So the takeaway of this special la niña year is that not only were there lots of storms with high ratio snow... but there was also a ton of water in those storms which is not normally the case at all.

[Montana St Alum]

We transitioned out of La Nina back in March, I believe. I think we're actually in between the two now.

https://weather.com/news/climate/news/2 ... -hurricane

[spopepro]

We transitioned out of La Nina back in March, I believe. I think we're actually in between the two now.

https://weather.com/news/climate/news/2 ... -hurricane

Yes, all of 3 days ago (tongue planted firmly in cheek). But the impact has already happened--there often isn't much happening in the spring in the west after the jet stream moves north. Sure, cut-off lows can still pull up some moisture and linger, but they're hard to predict.

And while "el niño/la niña" is like A1C--a rolling 3 month average, there's still shorter term anomalies... like the cooler water that is keeping the door open for bigger cut-off lows to roll through.

[Montana St Alum]

Hah! Yeah. Tres Picos is great wine!
But the point is that the weather pattern we have seen for the last 2 or 3 months has not been because of La Nina. La Nina was stronger 12 months ago (and we were approaching its third year, this last December or so) and we weren't getting these wet patterns.

We've been getting continuous flow, from west to east this year in the Western U.S. and Rockies. I hate the term "atmospheric river" but that's been our predominant pattern this year. There just hasn't been much oscillation in the jet that I've seen, but I don't watch it continuously.

I'm praying for an oscillation to the north!

I have no idea what's going on, but it seems unlikely to me that La Nina is the culprit.

[spopepro]

I do watch things pretty continuously. To say things were, or were not, because of la niña is tricky. This year set up like a classic la niña year with the big early storms. Atmospheric river events are very common in la niña years and we had a bunch over the last three. The thing is--usually a strong ridge sits up right along the coast in Jan/Feb and blocks storms. That happened in a big way last year, and the models all said that would happen again this year. The MJO sat in "the circle of death" (not strong--higher activity is a good indicator of a "ridge buster" event) and the PNA models kept shifting positive all saying "soon there will be a ridge and some dry weather". And then the models kept flipping around 5 days out, the ridge that was coming never did, and we kept getting the pattern of cold wet storms.

Granted--I'm hyper focused on California since that's where I am and ski (and climb, and fly...). We don't get lots of cold wet storms. The big wet storms tend to be warmer, and the cold storms usually fail to suck up enough moisture. Jan/Feb AR events, especially in big snow years, tend to cause catastrophic flooding (like in 1997). We had some tough stuff to deal with this year, but it was more wind and snow load related--the snowpack never got melted out by any of those AR events.

So all the way through Jan to now... it's looked like classic la niña storm tracks, just at the wrong time of the season. All the models were fooled pretty much all season long though and the ENSO is one of the more understood inputs. The excellent ENSO blog from the NOAA seems to indicate that we might need to rethink our understanding of how la niña details can predict Jan and beyond patterns. So maybe we are kind of saying the same thing. This year was just really strange and no one knows exactly why.

[bauerb]

Melt does not usually happen at a mellow pace over many months. In my town in Montana, last Spring it was cold, until suddenly it wasn't and then it started raining . the river jumped the banks and went right through town. Engineers have been working a full 12 months, all through the winter, to try and shore up the river banks. we have received nearly 6 ft of snow in just the last 10 days...melt-off is still a couple of months away in the mountains, but it will come hard. CA will also get it bad. Mammoth, Tahoe, etc will soon have an amazing amount of water to deal with. its all fun and games on the slopes, but hang on when it melts. "winter is coming"...meh, winter is fine. the challenge is Spring.

[JB TELE]

I'm going to be driving from Colorado to California to do some paddling up on the north coast in late May. Maybe I'll throw some skis in my truck and do some XCD skiing. I wonder if donner pass will still have enough snow coverage for an overnight backpacking on skis trip?

[Montana St Alum]

May of what year?
They will, as long as you get there before about early August! They have over 50 feet, I think.