WxUSAF

Ooohh...12z ggem is so close to the perfect scenario. Just brings the second storm a bit too soon so it’s a cold rain, but the track is near perfect.

Overnight euro and new parallel gfs were pretty similar. Paste bomb for mountains and far western burbs. So far I don’t like the 12z gfs at all. Although that 500mb low pass for the Dec 1 storm looks fairly amazing in isolation.

Nov 30 storm cuts west, Dec 4-5 storm is slow enough that it cuts too. Crap airmass after for a few days then we place all the hopes on threading the needle for one more storm before the PAC jet returns on Dec 10.

The advertised pattern clearly supports coastal storms or storms passing south of us in general. Doesn’t mean every storm will do that, but pattern is supportive of that. Question is going to be whether the air mass ahead of any individual storm is conducive to snow. You can see this with the Dec 4-5 window. We need the Nov 30/Dec 1 storm to give us a fresh cold air mass and then have the next storm move into it at the right time before it rots. We don’t need a *ton* of help for a suitable airmass in early December, but we need some. A climo air mass doesn’t cut it usually.

^thanks @frd. Maybe that’s the sort of linkage that could keep us chilly if the MJO gets to phase 6 in ~15 days.

Ha. We’ve got a nice pattern the first 10-14 days of December and already have a window or two picked out. That’s really good for December! Especially in a mod/strong Nina!

Hmm interesting. That seems in conflict with the MJO moving into the torch phases (4-6) over and east of the maritime continent. I wonder if mid- December will trend warmer on the progs. But MJO doesn’t always rule the roost, so maybe there are conflicting signals, but I don’t see what would keep us chilly?

lol, I’ve experienced more HECSs in my life than flash freezes.

Don’t know about storm chances or details, but EPS pattern even better than GEFS the second week of December. Big poleward PNA up into AK and the Yukon. And that configuration starts to bang on the SPV some

Dec 4-5 is the first period to keep an eye on. GFS and GGEM are weak and sheared today while euro is wrapped up inland. Need the Nov 30/Dec 1 storm to give us a good air mass.

2002-03 worked out well

It does. GEFS seems to be can-kicking on that orientation a bit, but also making the situation before that less hostile overall. I’d eagerly sign up to take my chances with that pattern anytime DJF.

Stealing something from phillywx... Since 2000 there have been 13 measurable snow events in the first 10 days of December at PHL. Let’s assume that’s about the same for us. So you’re looking at a 6.5% chance on any given day. But roughly even money or a bit better on measurable at in the first 10 days when adding that up. Given the advertised pattern, it’s hard for me to see that we’re in a worse than climo position. Hopefully that holds through the next 2 weeks.

Mods clogging up the LR thread with banter smdh

Fun active pattern for sure.

The precise axis of the PNA ridge is key and its a very subtle feature as you can see if you toggle back through the last 3-5 days of GEFS runs. We want as much N-S orientation as possible. Either way today’s GEFS has us BN for the first 7-10 days of December. Hopefully it’s not a dry cold. Regarding the AK trough, interestingly the extended GEFS has it west of AK near Kamchatka or NE Siberia all of December. That’s a pretty good location for us as it should encourage ridging over western Canada. Doubly so if a piece of the TPV breaks off and heads for eastern Canada as it shows right at the end around Xmas.

Airmass ahead of that storm is garbage. For there to be any chance, we need that northern stream low to bring it in ahead of time. I’m skeptical. Hope for wraparound snow showers. Chances go up the farther we get into December.

34 here

Agree with all that’s been said by @tombo82685 and others. The advertised pattern would more likely offer snow chances around Dec 5-10 then before. The Dec 3 period maybe has a snowballs chance if the needle is threaded somewhat like yesterday’s euro. End of the 6z gefs shows eastern Canada cooling down as the poleward PNA finally starts cutting off the Pac and dragging arctic air southward. Either way can’t be too upset about a very Nino-ish pattern going into December that should offer a few chances at least. Let’s keep that look through the next week and then we can get busy.

2017 is the last December where it actually snowed here

I appreciate this has been a polite discussion so far, but let’s end it now because I don’t think anyone’s mind is changing.

What outdoor sports are left at this time? HoCo fields mostly are closed Nov 1 anyway. There’s a few turf fields that stay open longer.

D7-9 EPS evolution isn’t one I’d ever turn my nose up at for a week+ prog. Cold air slides in ahead of the storm, but it’s close. Air mass ahead of that is hot garbage so need that northern stream low to get the cold air in. This was a big shift in the euro and EPS from yesterday which had a GGEM-like solution.

Might have to do a late edit to account for our December 2-3rd MECS.

Yeah, I don’t know if that SST pattern is unprecedented, but it’s pretty strange and unusual at least. I know DT was keying on that to think eastern US snowfall could be AN. Saw the CFS winter MJO forecast on Twitter this morning and it shows the MJO waves staying more in the Indian Ocean, which would be mostly favorable for us (phase 1-2). Maritime continent is the torch zone for us.