MAG5035

That’s gotta be the most confusing start time map I’ve ever seen. The SE quarter of PA got 4/5 start times criss crossing and whatever snow develops there tomorrow is gonna be starting way earlier than all of them lol. I really haven’t been a big fan of this storm threat in our region and just figures that it came back west enough a couple days ago to have to acknowledge the possibility. Although, I felt that the best chance of success was going to hinge on the developing wave of snow with the northern system and frontal boundary and if the storm phased early enough that the coastal wave could keep snow going for a time in the Sus Valley and eastern PA and provide a respectable event. The now presumed later explosive development of the coastal mostly takes that away and we’re left mainly with what the initial wave of snow can do, which will be during the day tomorrow. I’ll note that I’m not going to rule out York/Lancaster (and far eastern PA) catching some of the deform shield from the coastal. At any rate…. Initially the SW flow makes for the downsloping shadow east of the mountains seen on the higher res models but eventually precipitation does generate further east in PA as the coastal low starts taking shape and you start getting some easterly flow. So there will be flakes to be had probably for most of us late tonight thru tomorrow (west to east) but big question will be how much it will amount to. Models like the 3k NAM, RGEM, and the HRRR do show something, with the RGEM being the best showing a more widespread 1-2” with a bit more in York/Lancaster since it’s been pretty far inside with the coastal. So a general light snowfall is still on the table, but we’ll see how well this northern branch system does. There’s already precip in western PA from it and I’m about to get some echoes overhead (though I’m dry with a 28ºF temp and 9ºF dewpoint)

You must be in a hot spot up there haha, there’s three weather stations in and around Philipsburg on the Ambient site and two of them were just recently under -17ºF and the other is like -14ºF. There’s a South Philipsburg one on Mesowest that was -14ºF. It bottomed out at -5ºF here about half an hour ago, which is pretty impressive for being in town. Still about -2ºF. Impressive cold all up and down the 99 corridor as you can see on the above map and also the Mesowest map below.

Yea the 0z GFS really lined em up in it’s long range. I saw like two other events after that one. I’ve had thoughts about the pattern coming up but had been waiting to get much into it til we saw what this coastal was gonna do. I’ll probably elaborate more tomorrow but generally I think that while this pattern is going to shuffle around next week and give us what looks to be a 2-3 day warmup, I believe at least for now we’ll maintain a regime that’s going to give us chances through at least the first couple weeks of Feb.

Bouncing between +1-2ºF so far here in town. Already several meso stations below zero up and down the 99 corridor again much like last Friday Night. There’s a -6ºF near Claysburg (south of Altoona) and a -8ºF near Stormstown (just west of State College).

Quite cold tonight here, already down to 8ºF.

Well on the other hand, we were sizing up 10+ in all the Sus Valley around the D5 timeframe leading up to the 1/16-17 storm and the end game from that was the 980mb low literally going right over my head haha. Yea that’s probably not happening with this storm but the Euro take is definitely easily in the realm of possibility, or even closer to the coast than that. It depends on the degree of phasing and how quickly it happens. Additionally, this initial area of snowfall that develops with the northern energy is still showing and I personally think with a major amplification like this that this will eventually start showing better QPF wise the closer we get, provided we don’t see a major setback in guidance back towards what it was showing a couple days ago.

Nit picks aside on it shifting it’s swath east a bit (and south some with the initial snowfall development in our neck of the woods), GFS is still showing the same general theme of bombing the coastal storm out later and further east, only catching SNE with the more excessive snowfall. Euro has been exploding this into a big snowstorm starting much further down the coast. It’s a difference between a more run of the mill coastal with localized major snow (GFS) vs a sure fire NESIS cat 3+ considering how much of the megalopolis is within the 10+ in both the Euro and it’s ensemble mean.

The eastern third of PA is very much in the game for direct impacts from the coastal low, and for the state as a whole it may not be the all or nothing proposition it was looking like a few days ago if the coastal ultimately develops too far east for most in here. Models are pretty solid now on showing general snowfall developing across most the state Friday as the phasing northern energy drops down and attending arctic boundary presses. I Mentioned this in two posts on Sunday, even on the first post during the day when the coastal aspect of this wasn’t anywhere near close to C-PA and I was still skeptical on a bigger storm happening at all. If the coastal trends closer like the Euro this setup could help in terms of a more expansive precip shield (even though the axis of heaviest would probably tend to be just east of most of the subforum) What’s ultimately changed is the timeframe of this phasing occurring (faster). This was really well explained in the Mount Holly AFD that was shared in here first thing this morning. The faster ejection and phase presumably keeps the western ridge axis in a much more favorable positioning for us and not too far east. This is what changed the game with this and now that all the models are on board for the bigger storm happening this could absolutely trend better. We’ve been running a progressive pattern so it wouldn’t be too much to see this speed up a bit more. It also could trend back the wrong way too, let me be clear. The shortwave timing is very important. At any rate, for any thought of the Euro being over amped the 18z NAM in “guru” range said hold my beer lol. There was a large difference between 12z Euro at 90 and the 18z NAM at 84hr.

You’d probably get more speed going down Sandy Ridge Mountain from P-burg to the Snappy’s in Bald Eagle lol.

Just got home, all roads are pretty rough. Measured 1.5” with moderate snow and 28ºF. Back edge is coming soon but it’s probably going to get to 2” by then.

Currently up at Blue Knob summit, the snowboarding was pretty decent this afternoon. Plus got some time in the new snow falling.

Well I’m surprised @Blizzard of 93isn’t around tonight with updates haha but there has been a distinct shift in guidance (ops and ensembles) tonight towards this coastal system being a good bit closer to the coast and quite strong as it has been occasionally showing inconsistently on op guidance (mostly the GFS). Tonights 0z Canadian actually gets the coastal system back into some of the Sus Valley which is roughly supported by it’s ensemble mean taking a developing low off the coast just inside the benchmark. The GFS and Euro have benchmark systems, which also show that approximately on their ensemble means. The Euro (in a massive difference from 12z Sunday) specifically detonated New England with exploding low pressure at sub 960 near the benchmark to an eventual 946mb in the Gulf of Maine. Despite a few big C-PA hits on a few GEFS and Euro EPS members, the coastal storm is still ultimately too far east for us but this was the kind of model cycle I’ve been waiting to see in terms of collective support among all guidance of some kind of bigger coastal storm and associated phasing. And this is starting to show right around the D5-6 timeframe too, so we’ll see how this evolves. Like I mentioned earlier, what’s also to be considered is even if the coastal misses east is lighter snows from the northern branch wave that phases in to pop the coastal low. That’s also showing to a degree on guidance now as well.

We’re probably going to get some kind of repeat of this starting late tomorrow afternoon into tomorrow evening with clipper #2 as well. New 0z HRRR, and this seemed to do half decent with today’s event.

About 2.5” or so with light snow falling. Temp still between 27-28ºF. You can see how fluffy the snow is.

28ºF moderate snow. 1.7” now on the snowboard. 2” seems pretty attainable, I wonder if this can squeeze out 3” here. I think CTP should have issued advisories for at least the Laurel’s and maybe even a few of the central counties to match up with PBZ’s expansion of advisories they did overnight last night. If it’s a fluff bomb here at 1300’ it’s definitely one up at 2-3k feet in the Laurels. There have also been some issues on I-99 this afternoon, esp in Centre County.

27°F/25.5°F, light SW wind. Light to Moderate rate currently after having a nice burst for a awhile. Over an inch.

Yea had an initial bout of steady snow that’s put down a light coating on snow surfaces and some of the best stuff is moving in from western PA now with a decent steady snow resuming, so we’ll see how much make’s it off the Laurels. I still think it’s doable to see a coating up to an inch in parts of the Sus Valley since better stuff will be trying to come in late afternoon. Actually looks like some patchy snow is trying to develop (via LWX radar) from H-burg south between 81 and 83, so will have to see what reaches the ground. Again it’s going to depend on the downsloping component. The stuff in western PA actually looks pretty decent. Short/near term guidance has been bringing the best stripe of snow across closer to 80. So I would favor the best chance of the T-1 to be H-burg north… but I think anyone in here has a chance at seeing something. Still not high on the coastal chance next weekend. At the moment this may back in enough to be a New England or even Mid-Atlantic east of I-95 event but I think our only chance of snow from that may come from the actual northern stream disturbance that eventually fires the coastal.. which would probably be a lighter event like we’re seeing today. The MU director’s take that @Itstrainingtimeshared I think sums up that situation pretty well.

Looks like the winners of the 0z version of the GFS snowstorm sweepstakes is the southern New England gang. Extreme eastern LI and Connecticut, all of RI and eastern Mass get rocked.

Here was the comparison between the 18z and the 12z. This things only beginning to materialize by the 144hr timeframe which is as far out as the 18z Euro EPS and control goes. 18z 12z I’m intrigued by the timeframe to be sure but I’m not jumping gung ho on this threat until I see some more consistency on the operational guidance and ensemble guidance to start reeling the mean back towards the coast line. Ensembles have been seeing it to a degree but everything (GEFS, Euro EPS, CMC ens) is generally way to far out to sea to have us in the game for anything. Still pretty far out in range though, like I mentioned I think yesterday the storm last week really didn’t start showing consistently until it was around D5-6 and the pattern also makes it hard to see threats even in the medium range with the progression and lots of moving parts.

Here’s the 24hr snowfall version of that snowmap. Next.. lol.

It certainly could simply because it will be a high ratio snow, likely of the 18-20:1 variety overall and perhaps even higher ratios in the mountains where there will be some extra upslope lift on the westerly flow. Whole column from 850mb up is in the ideal temp range for snow growth. I think the Laurels counties probably could get an advisory type deal (PBZ already has them out). The big thing will be seeing how the precip makes it away from the Laurel’s and how much of a downsloping shadow gets cast towards the Sus Valley. Good chance most see a minimum coating to an inch though. This whole process looks like it may repeat itself to some degree Monday evening regardless of what the southern stream wave Tuesday does because the second clipper low running the northern branch now looks like it’s going to run ahead of it. Then later Tuesday would be the timeframe for the southern stream system to do something. GFS/Euro have become extremely disinterested in doing anything with it and instead squashing it into the Gulf of Mexico. Our newly anointed guru of the 60-84hr range the NAM brings it up enough to generate some light snow in PA on the arctic frontal boundary, which I think is what we should look for from that system as a best case scenario since we have the northern branch clipper low coming out ahead and thus not much opportunity to amplify and try to turn up. Either way though, that’s three distinct chances at snowfall for C-PA the next 3 days even if they’re lighter events. And I have pretty high confidence in the first 2 doing something.

-3ºF was the low here this morning. Browsing the meso obs it looked like a lot of lows in the -7 to -10 range outside of town up and down the I-99 corridor. Weather station in south Philipsburg up by Atomix had a -13ºF. Looked like the big winner was the one in the northern tier near Smethport that’s always super cold, bottomed out at -21ºF. Euro def did well seeing the radiational cooling.

I”m within the city of Altoona but on the corner of town only a couple miles from the Allegheny Front. I would imagine there’s already a couple spots outside of town that are below zero. On Mesowest there’s a station at the lower end of my county at -1ºF and I also saw a station on the outskirts of State College reporting a -4ºF.

Cloud cover could be a part of it maybe, looked like the LSV was under the high cloud deck most of the early evening from the system that is currently a Carolina snow/ice event.

Down under 4ºF already here.