jwilson

The good news is the seasonal trend has been to shift things south closer to the deadlines. Of course, with the pattern change, undoubtedly that trend will get flipped for the opposite when it no longer could favor us.

I used to chat on those forums in conjunction with this site (which used to be easternuswx, as well). Been a while since I've been there, though. As for this weekend, I'm not buying any single OP solution just yet. All the finer details will have to get worked out as we get closer to the event. The most important note right now is that there is a signal for something big, and a pretty alarming signal at that - showing up on quite literally all the models a week out? Pretty incredible and honestly, rare. Being in the bullseye this early would be difficult to deal with, though. Don't want to get too invested in this system given the rather unusual path it could possibly take.

I like the period after this weekend a lot more. Say between the 19th and the end of January. I think we get at least one significant event in that window (6" or more). This upcoming storm may still provide something, but I see it as more of a table-setter than the main course.

Well, that first suppressed system brought in this current dreadful pattern, maybe the second version can usher in the pattern reset? Progressive, flat flow and southern stream looks shuddered by a strong NS vort. Wouldn't surprise me to see that high pressure drop south as we get closer. Teleconnections pretty marginal. I'll be flying on Sunday so I'm okay with this one missing. Edit: FV3 and CMC are still showing a possible storm solution. Perhaps a big one at that, but until they get support, I won't trust those two alone.

FV3 has already teased us with some digital KU classics this season, only to fold to the old crowd closer to the event. Not buying in yet. I am a bit apprehensive about the FV3 replacing the current GFS, however. Seems - at least over the last month or so - it has a penchant for showing a big tease too soon. For 300 hours that's typical, but a week out? Hopefully it's nothing.

At this point, odds would favor that it should snow in January. Basically, getting shutout would place it in the bottom 5% of winters. Of course, things can theoretically recover in February and March. I don't expect a 2001-02 repeat.

Whoops. Well, if that ends up being the total come the end of January, it would pretty much fall in line with those two outlier years moreso than the other years with multiple - but small - events. I mainly meant to discern how rare it was to be shutout (or nearly so) in both months. So far this year looks closer to the low-end extremes. Hopefully not to be repeated soon.

Out of curiosity, I was looking through records for when the last time PHL failed to measure snow all of December and January. Recently, 2015-16 was pretty bad until that one large event salvaged things. Without it, both months would have had 3" total (none in December). 11/12 - 2.5 total (none in December) 07/08 - 2.6 total 06/07 - 2.2 total 01/02 - 4.0 total all winter (zero snow in December, Feb, or March) 97/98 - 0.8 total all winter (I remember this stinker) 96/97 - 1.7 total 94/95 - Here's your true winner. Technically, there were three "Trace" measurements in January, but other than that, total shutout. I went through 1968 and found one more year of zilch (72/73). In fact, as far as I can tell, the winters of 1972-73 and 1997-98 are the two worst on record in terms of snowfall. So, in the last 50 years, only twice has there been no real snow measured in PHL between December and January. By that I mean anything other than "Trace" events. Although, it is more common than I would have expected to see one of the two months between December and January to get next to no snow. It looks like this year could be another in that list.

The long-range volatility all season is what has me concerned. Been that way for a while now. If the MJO loops back around into Phase 6 again after passing through 7 briefly, that's just a kick in the pants. Maybe it doesn't even make Phase 8. 96-97 analog probably a pretty good one to follow. Seems people expected a more influential Nino (which we haven't had), but the pacific, among other things, is keeping the cold air away from much of the CONUS. We aren't torching as there isn't much of a SE ridge, still above average. Feels like we're simmering. Going through all of December and January without snow would be pretty bad. February 2010 would have to re-appear to make up for it. March snow isn't as appealing.

I went to private school (Phil-Mont) and we had off for just about anything. I remember one day it straight rained and our school closed (the threat of snow was forecast, but it never materialized). My brother was stuck in public school and rarely had off the same days I did. Heck, we got off a whole week for '96.

I agree with you on that. For many places in the East, December is not a snowy month on average. Pittsburgh is a tad different, probably due to lake effect. Long-term means indicate December is more often a snowier month than March in these parts (though not by much), but including this year, 4 of the last 5 winters will have been below normal snowfall in December. Last year we managed 13" in December. 2014/15 and 2015/16 were basically a trace, and 16/17 was 6" total. This year obviously isn't much. Average over thirty years to 2018 being 8.2 inches. I was attempting to see if there was a correlation between a snowy November and a dry December, but it doesn't appear the case (at least not for Pittsburgh). 4 of the last 6 Novembers have been at or above average for monthly snow, though.

I wondered, with the MJO, how much that amplified Phase 5/6 would affect the atmosphere given all the other conditions. Phases 5 & especially 6 are associated with warmth flooding the entire CONUS. Things will (hopefully) look much more favorable once we get into Phase 7, which is a near exact inverse of Phase 5. The question, I guess, is whether the MJO continues that momentum into other favorable phases (8 and 1) or dies into the COD. The latter option is probably better than what it is currently doing. Still, I wonder if that much amplification would be too much of a good thing? We've already seen one suppressed system this year.

I really want to laugh at whatever the GFS is doing, but my subconscious tells me it will find a way to verify.

The whole evolution here is quite odd. Progressive flow and marginal temps. Haven't seen the Euro, but the NA models together don't look all that similar. GFS is a relatively weak and warm wave 24 hours later than the FV3. The Canadian likewise holds the system back until NYE and is even warmer. The closest to the FV3 might be the ICON, which has been fairly consistent with the timing on Sunday instead of Monday, though it doesn't look like much to behold. I honestly can't figure out how many waves we're getting here. Looks like Friday/Sunday/Tuesday or Friday/Monday. Though the GFS has almost 48 hours straight of rain for the southern states.

Don't know that there's much promising in the near future. Seems we are stuck with a transient block that only appears in minuscule waves, and there's no real cold to be found yet. A couple waves and/or clippers over the next couple weeks, but the models can't sort them out just yet as to when and how many. I think people are holding out hope for later in January. The long-term variability has me uncertain, but traditional El Nino climate would indicate back-loaded winters are more typical, with February perhaps being the best month for snow chances in the East. Meanwhile, the MJO appears to be heading into an extremely amplified Phase 6, which correlates to warmth all over the CONUS. It literally goes off-the-charts according to the current GEFS mean. If it can maintain that momentum in Phase 7, 8, and perhaps 1, that might be a good thing (or too much of one). Cold and dry, warm and wet are - for now - the only reliable metrics.

Here comes the Christmas torch! Hopefully it evacuates by New Year's so we can get back to this lovely cold and dry pattern.

That northern stream confluence seems to keep getting stronger as modeled. Getting to the point where we have to cling to a phase solution, and those are always low-probability events. I'll keep watching, because there's always the chance with this type of interaction we could have a late-game hail mary of sorts. At least this looks to be a winter of chances. Can't ask for more than that.

I should probably stop watching this so often - though I love the chase and all - but the one good thing we had on our side just went way south (18Z FV3). There's a piece over the midwest which is acting as kicker along with a diving shortwave in the Ontario/NE area that acts as a suppressant. If that New England s/w can move faster (out of the way) or the piece in the midwest phases with the energy over the south and pulls it back, as I would understand it, those are the two ways we can get an event more north. The latter option could result in a rather large system, perhaps historical proportions, while the former is something still decent but less notable. Of course, it remains to be seen how far north and west we can get with the primary system.

Yeah, unfortunately, the FV3 (and to a lesser extent the GFS) is the only thing we have on our side right now. It has been fairly consistent while also shifting north noticeably over the last few runs. At least enough to get Allegheny County into the mix (certainly not directly, but snow instead of dry). Meanwhile, the Euro and Ukie are squash city with the high sitting over State College.

I know it's still relatively early, but the models have largely been consistent with a southern solution for a few days now. Looks like the battle line is getting drawn across the Mason-Dixon in terms of northern progression of the snow. I find it incredibly strange to get such strong confluence this early in December, but at least for right now, that's what we're looking at. Going back in time, Richmond's biggest December snowfall is 17.2", and that occurred in 1908. They've had four other events over ten inches (1917, 1935, 1958, and 1966). The storms in 1908, 1935, and 1966 were late December. The 10.4" in 1917 fell between the 12th and 14th. A storm approaching and exceeding 2' of snow between December 8th-10th would essentially be unprecedented. However, given the passage of time, perhaps they are due. Now, a north trend or wobble is somewhat predictable, even expected, with the models, especially later in the game. As we move forward this week, the question will be whether we can get enough northward movement prior to the onset to sneak into the crosshairs. Places like D.C. might be in better position to benefit. I am worried we're too far north to be in the game. The GEFS (ensembles) haven't shifted noticeably north over the last few days. They've kept the heaviest axis of snow in Eastern WVA/Western VA. The Euro ensembles appear to be in similar agreement. Looking at individual members, none of them get Pittsburgh appreciably in the game. There are a couple close calls, but the best ones are all fringe jobs, at most. There is still time for change. I am concerned, though, because outside of that early FV3 run, there haven't been any northern solutions (maybe the CMC is an exception; I'm ignoring it until it has support). They went further south for a time, but again, no intimation that the confluence will weaken enough to target PA. There are quite a few interactions at play. Keep a look out, but for now, I wouldn't really expect anything (big surprise, right?).

A blizzard for Atlanta in early December. Could you imagine that?

Right in the sweet spot, then! (Kidding, of course) Beautiful banana high, juicy southern steam. Signal remains. Euro and GFS not quite on board yet, suppressed solutions, but if there's such a thing as weather porn, that FV3 run is it. I'm sure we'll see plenty of spread upcoming. Indeed, even a couple days later, the PV flow looks improved, pinching off instead of getting trapped over AK. It may not dump cold over us, and I'm sure there will some sort of warmth and relaxation of the pattern, but for now it appears we may not get locked into anything over a longer term. Lots of moving pieces to keep the weather shuffling. I was worried we'd be starting at 70 on Christmas, which I guess is never out of the question. At least through the 10th or so we should have a ride of some kind.

I made the mistake of looking at some long-term forecasts. Does not look great right now. I'm hoping - as it tends to do with the cold snaps - that the ensembles' warmth is overdone. GFS and Euro both. That dreaded warm December I fear appears like it may be a reality, fueled by a raging +EPO. Maybe it's a transient shift instead of a long-term pattern setting up, but we've seen single, strong indices dictate winter before. If you want to get really crazy, there's a storm signal around Christmas that might be interesting. Yes, that is what I choose to believe.

Here's a shot from the snow the other day: Everything had a nice coat on it. Really set the mood for the season. Made me wish we got snow more often in November and around Christmas.