December 2020 Forecasts and Discussions

[Bonovox]

Of course its possible, but from my understanding, its rare.

Rare doesn't mean it never happens.

[AbbyJr]

I disagree.

The setup modelled on the GFS is similar to the December 2017 event though, which was mostly cold rain due to a lack of cold in the interior.

You would need a very cold trough for low elevations to score without arctic air. Its possible as you say, but its not likely in my opinion.

That said, I would very happy if you proved me wrong.

[AbbyJr]

Rare doesn't mean it never happens.

Absolutely.

[Catnip]

You don't need any "arctic" air to see accumulating snow in December. Cold onshore flow can do the trick, especially if you are over 50m.

This.

And there were many years where this worked out very well for those with a bit of elevation.

Doesn't seem to work out like that too much anymore though.

[AbbyJr]

We can do well with cold onshore flow. Even sea level.

But 950mb temps look so marginal from the maps Bonovox posted. We'd be relying entirely on precip rates for any real accumulating snow.

If only a low took this track back in January when we had temperatures down to -10C.

[Typeing3]

The setup modelled on the GFS is similar to the December 2017 event though, which was mostly cold rain due to a lack of cold in the interior.

You would need a very cold trough for low elevations to score without arctic air. Its possible as you say, but its not likely in my opinion.

That said, I would very happy if you proved me wrong.

Used to happen a lot more in the past. Warming SSTs off our coast have made it a lot tougher recently.

[AbbyJr]

This.

And there were many years where this worked out very well for those with a bit of elevation.

Doesn't seem to work out like that too much anymore though.

That was precisely my point. Its rare but it can work. Seems much less common as of recent.

[AbbyJr]

Used to happen a lot more in the past. Warming SSTs off our coast have made it a lot tougher recently.

Yup. Those warmer SST's have really costed us in terms of low elevation snows.

[Typeing3]

This.

And there were many years where this worked out very well for those with a bit of elevation.

Doesn't seem to work out like that too much anymore though.

1280_AzeTBgicZFa7.png

[Catnip]

Used to happen a lot more in the past. Warming SSTs off our coast have made it a lot tougher recently.

Agreed.

I remember years where I would have ft of snow, and once you drove down into the lower elevations, they had barely a trace. A bit of elevation played a big role.

Cool/Cold moist NW flow produced many decent snowfalls over the years.

As mentioned, not so much anymore.

BBY mountain is a good example of this as well. They also seem to struggle in marginal setups, where in the past it would be guaranteed snows.

[Catnip]

Yup. Those warmer SST's have really costed us in terms of low elevation snows.

[Bonovox]

Used to happen a lot more in the past. Warming SSTs off our coast have made it a lot tougher recently.

Indeed. The blob currently isn't as bad as it has been and is cooling slightly, but definitely.

[Typeing3]

Agreed.

I remember years where I would have ft of snow, and once you drove down into the lower elevations, they had barely a trace. A bit of elevation played a big role.

Cool/Cold moist NW flow produced many decent snowfalls over the years.

As mentioned, not so much anymore.

BBY mountain is a good example of this as well. They also seem to struggle in marginal setups, where in the past it would be guaranteed snows.

Even lower elevations could get something out of cold NW flow setups in the past. I'm only at 25m but I recall some pretty decent snowfalls (10cm+) in the past with cold onshore flow.

Driving up to Mundy Park in those setups was like taking the road up to cypress or Seymour. You guys up the hill would get hammered.

[Catnip]

Even lower elevations could get something out of cold NW flow setups in the past. I'm only at 25m but I recall some pretty decent snowfalls (10cm+) in the past with cold onshore flow.

Driving up to Mundy Park in those setups was like taking the road up to cypress or Seymour. You guys up the hill would get hammered.

Yup.... the good ole days.

[Typeing3]

Yup.... the good ole days.

Indeed....remember this one?
https://www.youtube.com/watch?v=7_dIK3Dcj6o