Bob Chill

Heh, 18z gefs is a straight weenie run d10-16. All the hits are during that time. I scanned the members and most hits are coastals and not improbable weird crap. Prob a random blip as it came out of nowhere or... the gefs just discovered utopia

I was in the rockies that year and 2 things happened I'll never forget... my hands literally froze to the steering wheel of my truck and a tear froze my eyelashes together and I couldn't open my eye until I pulled the ice off. Don't remember exact lowest temps but -30 to -35 was common

The Pac air flood leading into Christmas was discussed at length 2 weeks in advance and people predicting shutout and warm conditions into the holidays hit it on the head from 1-2 weeks out.

Something less obvious worth keeping an eye on is the UK ridge pressing towards iceland/greenland. That can help block up the atlantic and fight off ridging in the east. This plot is a run over run change and not a height anomaly map. You can see the tendency for higher heights in that region as well as lower heights in the Atl near the 50/50 region. The UK ridge is pretty stout by d8 so it's prob not a phantom and could play an important role on how we get a flawed event down the line instead of suntans.

@psuhoffman Yep, once the big +AO showed up in combination with crappy ridge/trough alignment in the ePac leading into the holiday I knew it was going to be a problem for longer than just a week or so. I said as much when the crappy Pac showed up before Christmas but there was know way to now if it was going to dig in an hang around for a while. It's safe to say it's going to hang around for a while now. I didn't have high hopes leading into this winter as I was thinking a dud was on the way back in Sept/Oct but Nov came in like a lion and made me second guess everything. The big +AO during the first half of Dec was the first warning sign. The recent flip to a -AO was a bit promising but it didn't lock in. Now that we're back to a pretty sig +AO regime it's time to trim expectations and just sit back and hope a fluke/flawed event pops up. We're half decent at that around here so I'd be surprised if Jan went snowless.

It's not the pacific. It's looking at an op run waaaay beyond any type of useful range and expecting anything to be remotely correct that's a problem. It makes no difference what the gfs shows in the long range. Nothing is changing the fact that we are in an extend hostile period that may continue for the next 2 months or it might flip to deep winter out of nowhere. There is literally nothing worth tracking winter wx wise for the next 7 days minimum.

Yea, I thought that was a little silly honestly. @leesburg 04 says it well. There's a big difference between big game hunting and simple winter wx tracking. Is there any sign of a big dog pattern? Nope, not even close. Are there signs of enough ingredients available for some winter wx? Yea, all guidance has the door open for our most common way of getting snow... jacked up imperfect pattern that may accidentally work out. What's saving us now is no sign of a SE ridge. Amplifying progressive flow should deliver multiple winter airmasses during early Jan. We just need some good luck. We've had a couple bad breaks already. Time for equilibrium to kick in and throw us a bone.

@psuhoffman find me some analogs of what the eps and gefs are evolving into in the next 7-15 days. Lol. What a jacked up pattern. -PNA/++AO but is still lining up cold delivery (could be extremish cold) into the east. Hypothetically... if we get 3-4 separate shots of cold continental or even arctic air I think we can pull off an event before mid Jan. Def not a long track type of event as flow rippin and bucklin all over the mid latitudes. Just need choas to take over and get things lined up right. Ice, mixed, or even cold powder is possible. It won't come easy or be spotted from a distance but it does look like we're back in the game in early Jan

I believe models are converging on an unusual epac ridge axis that puts western canada into the deep freeze as the ridge axis runs along the coast. It's a weird pattern in general but hey, get canada into the deep freeze without a SE ridge and we'll get some cold. Get enough cold and it should accidentally snow

EPS is looking much better down the line (not the same as looking good. Lol). Especially in the Atl. Also moves the tpv out of AK fairly quickly and is building an -epo ridge. Mid level temps are looking cold by d15 so some of the arctic air in AK is getting displaced into the mid latitudes. All in all I'll take the 12z eps run as a Christmas present.

Doesn't work out on the run but I'm not mad at the CMC's version of NYE

It's not much and I won't share any thoughts about what I think about early Jan but... EPS shows there's more than a 1% chance at an event around NYE

I would love for JAX to get hit like that. It would be national news and something that millions of residents would never forget.

Yea, damned if you do and don't with the deal around the 30th. The only thing that can bring cold enough air into the mix is NS phasing and NS phasing almost guarantees a cutter. Euro cuts off the shortwave tracks the shortwave under us but with streams completely separated there is no cold to work with at all.

Everything is turning into a bit of a mess from a predictability standpoint. I've conceded that we literally have no idea what may or may not pop up in the next 2 weeks and also that the general hemispheric pattern will remain quite unfavorable for decent event. Once we start getting some fronts rolling through with continental air and progressive flow then chaos can take over and accidentally snow on us. Trying to predict that over a week in advance is a waste of time. No way to spin or sugarcoat where things appear to be heading. There is no longer any hint of a good hemispheric pattern setting up anytime in the near future. Crumbs, scraps, and accidents appears to be all we're going to have to work with.

Euro wasn't far from a much better outcome. A tighter spacing/flatter ridge in front and more confluence from the atlantic and storm track suddenly goes from cutter to coastal. In between solution would be CAD then flip. This is a decent panel right here Flatten the top of the full latitude ridge and we snow

12z gefs is picking up on something around NYE and the CMC op hits us good The GEFS members that work out are similar to the CMC progression with a wave or waves getting suppressed by transient 50/50 atl blocking. IMO- it's a huge longshot but there are enough hints in that time frame to keep it interesting.

@frd Wes did a great scatter plot with AO and 4" or greater snowstorms. The plot clearly showed the importance of a -AO and 4"+ storms for DCA as the correlation was somewhere around 70%. Might be higher... I'm not digging too deep into anything right now as we're still over a week away from even being in the longshot game. Jan can be a friendly month with snowfall and hostile teleconnections. Just need some luck (as always).

Some interesting looks. I'm actually a little confused why snowfall is sparse on both the eps and gefs. Hopefully that picks up soon. I am really liking the d15 height spread. Nearly every one is wintry and has potential. A lot of broad troughs in the mix. Get that going and our odds of snow are well above normal. About half the members have a closed ull of the coast of Socal. Jan 87 redux.

Took a closer look at the 18z gefs. I suppose there's a longshot chance around NYE. Something to watch as we pass time wearing sunscreen.

Eps keeps trending colder d10-15 but looks pretty dry with limited snow chances. Very weak signal around the 4th-6th. Gefs is similar with things turning dry after we transition to cold around NYE. 18z gefs had a bit more of a signal for potential between the 4th-6th. Right now guidance agrees on the big picture in early Jan and also agrees that snow chances are pretty meager and don't expect much before late in the first week of Jan. Of course this is all subject to change every 12 hours or so

Yea, sure seems to be moving in that direction. Quite a bit of spread on how things evolve in early Jan. So much so that I have no idea where this is all going other than some mid winter cold is prob on the way. How long it lasts and whether or not frozen precip is involved won't be known for 7-10 days. With the way this year has gone I'm expecting some brand new ways to worry are in our future. Lol. Cold/dry is on the list. Lol

9 times out of 10, flipping out of a sh!t pattern and into a colder pattern doesn't include snowfall. Feb 2015 was an exception. We typically need the cold pattern to establish itself for a week or so before chances start popping up. Going off history in these parts based on what I'm seeing now... our first real chance prob won't happpen until after 1/5. Just a total guess but it's how we roll.

One important step that all guidance is showing is splitting unmitigated pac flow sometime between the 26th-28th. I would like to think that part is close to locked in and won't get kicked down the road. That's a very important inflection point.

The gfs op and gefs/eps are all signaling a return to a very amplified but still progressive flow. Wild swings on ops run over run will continue for days. Overall guidance (although turning cold) doesn't look promising for snowfall yet. Gotta crawl walk and run here. Crawl phase appears to end sometime around the 30th. Beyond that? Good luck guessing.