Terpeast

Yeah I was out of school a lot, but hurt myself falling on ice. Either way I don’t see this happening. Replay it now, precip will mostly be rain. Early-mid January could go either way… if the pac jet lets up a bit and allows the aleutian low to retrograde, we could get 2 week of cold. But if the trough sticks itself over AK, we torch like 2023.

Really not a fan of 93-94. We may have gotten a lot of record cold, but it really isn't a snowy pattern. Lots of mixed precip/ice with the baroclinic boundary more inland.

This Aleutian low had just formed only recently, so there’s not much of a track record for it verifying further east this season. What has been happening for a while is that the epo has been verifying lower than forecast, cold has been trending colder in shorter lead times, and the torch keeps getting delayed. But we can agree that December has been a volatile month and no one pattern has been locking into place. It may be correct to attribute that to the fast pacific jet.

Well, its December and an el nino longwave pattern for Decembers tend to be warm. i just hope that the mid-lat atmosphere doesn’t flip Nina in January and maintains a torch pattern the rest of the winter. That’s the worst case scenario

I see signs of the aleutian low retrograding at the end of the ensemble runs, meaning better cold source and potentially -epo. Too soon to make a call one way or another.

Ensembles show signs of aleutian low retrograding at the end of their runs, bringing more cold air back into our source regions (it’ll get mild locally for a bit)

If canada is gonna torch, I rather it be NW canada than SE canada

1972-73 stood out to me for last year (as the worst case scenario)

Very nice trend. I like how the ridge axis is shifting west as it comes forward in time.

Looks like +PNA decembers tend to roll into January and maintain a ridge out west?

So far I have had only 1 60+ degree day this December (the 8th).

Pretty close to that. 1.23” total

I think we just have higher expectations in the 6-10, 11-15 day range whereas we used to only look out to 5-7 days. I think the models today are better than even the euro used to be, but the lead times have gotten much longer.

The aleutian/GoA low is yet another surprise that many of us didn’t see coming this winter. I didn’t myself, but as I said before, this winter will find a way to throw us a couple of curveballs. We want to root for the GoA low to retrograde into the aleutians so that we can get a nice PNA to pop, and a negative epo to top it off. Worst case scenario? GoA low stays put, and then La Nina reasserts itself with MJO reloading 4-6 for a SE ridge. But I don’t think the GoA low is durable, and the jet should retract some.

Point taken. I’m actually glad to see this.

Yeah I was thinking about that thus morning. Yesterday we were barely into the low 40s for the high. Today we blew through the 50s to top out at 64 imby. No one was under 60 except near the bay or in the mountains.

Good post. When these things happen, I tend to look for spatial areas where models (and individual runs) are more in agreement with each other. In this example, I see better agreement on warmth over the western US, implying a western ridge. The contradictory forecasts over the east may just indicate greater variability and/or higher uncertainty.

I think those 30+ ssts run deep, but even temporary sfc cooling will open some windows where MC forcing isn’t dominating everything

Probably some temporary cooling in the warm pool due to ongoing convection in that area

True, good point. Looks really noisy. In that situation we’re probably better off looking at the hollmover charts, but I’m skeptical of a standing wave longer than 1-2 weeks because even strong tropical convection is almost always self-limiting. It will either weaken or move.

TT doesn’t show that. Can you post a map?

I think for now the models might be latching into the warm pool bias due to persistency, but not sure it will stay that way forever (despite what snowman might be shouting from his rooftop). I think this winter will find a way to surprise us.

Lock it in

Previously the GEFS had it stronger going into 7, but now weaker lime the EPS?

I know its 84h, but the NAM has the freezing boundary further east than gfs or euro