MAG5035

Lol all this Miller A/B talk is fun but I’m sitting here wondering why that EC run popped a low on the coast so quickly way in front of the primary wave.

Big western ridge too. Boise, ID is the often referenced point for having the western ridge axis through for C-PA snowstorms and it sure looks like a case of one there. This is the amplification we needed for today’s storm.

12z Euro Ensemble >3” probs. Pretty decent, and dead center on PA swath wise.

Euro didn’t really even have all that much QPF either. The 10:1 DC area vs LSV was more like a 4-6” vs 2-4” event. That’s another thing to keep an eye on is the QPF aspect. Last night’s Euro was one of the biggest QPF runs despite having decent but not heavy events on some of the other runs. I could see this going either way, being a run of the mill quick hitting wave of snow or a more significant widespread event that merits a NESIS ranking. I just don’t buy the GFS non-event, but yea I sure would feel alot better if it got on board soon lol. Still in the mid-range too, which always has these shenanigans. It’s not that far out though really being at D4. We’ll probably be able to have some hot NAM takes this evening.

Yea that looks like the 10:1 map which shows a bit heavier QPF down there. I”m using Kuchera for this without really worrying about inflated totals here because if this event occurs in non-GFS fashion it is going to be a cold storm in PA and the column looks great for good ratios for us. Harrisburg has 4.3” on Kuchera with 0.29 QPF (just under 15:1). Just looking roughly at the maps at different levels, 850 temps are -6 to -8ºC (falling) and 700mb temps across PA are a degree or two either side of -15ºC (inside the ideal -10 to -20ºC range for the snow growth layer). So with that I would say a ratio like that in C-PA is completely reasonable. Not to mention climo for C-PA in January for snow ratios is roughly 12-13:1 and this looks like an actual January type snow event. My personal take is the GFS is having trouble popping the wave with the cold airmass in place and presenting it’s tried and true SE bias of the last x number of years/decades. The set up and shortwave is there at 500mb like everything else and I really don’t see a huge difference other than maybe the GFS is somewhat less robust with the shortwave.. maybe. There’s a much better defined ridge out west for this than for today’s event, so with more amp in the pattern I really think something’s going to pop like what the Euro/Canadian and ensembles (even the GEFS to a degree) have been already been fairly solid on the last couple days. The immediately preceding shortwave over the Lakes that sets this up with the cold and etc probably takes the cutter option away and big question is placement of the best snowfall. Even if it did put the best precip in the 95 corridor again, this one should be more expansive with the shield.

Okay, I got maps loading now. C,mon guys.. you make it sound like PA got blanked out. What part of that suggests “Mid-Atlantic special”?

I can’t get anything on Weatherbell to load up model wise. Did the weenies crash it? Lol

Boy that’s a brutal cutoff looking at the cameras going up 270 from the beltway. Nothing on the ground in Frederick.

Best run yet of the Euro with the 1/7 storm, really upped the totals. Like I mentioned last night this event is going to be cold on the snowy side. Little mixing at all in PA, looked mostly relegated to far SE PA (Philly). Tennessee Valley-Delmarva transfer. I don’t understand why folks keep asking “where this storm has gone”. Good thing we’re not the Mid-Atlantic forum, someone would say go look for yourself lol. **Edit to add on 0z Euro ensemble stuff as well. Also, I’m not saying the GFS op is wrong or anything, but again….it’s literally the only thing that doesn’t snow on us with this the last several runs. Even the 0z GEFS has half decent 1”+ probs for PA.

It is kinda brutal to watch this evolve. The surface low goes from GA through the interior Carolinas to near VA Beach which is often workable for a good portion of the subforum. It’s a great shortwave but a tight system and there’s not enough amp in the pattern to bring it up the coast some or northern branch interaction digging into it to draw a much broader precip shield.

0z NAM starting… gonna be the most important model run of our lives coming haha. I need to nail down how thick the cirrus deck is gonna be here tomorrow.

18z Euro ensemble >3” probs for the 1/7 storm. >1+ was more than 50% for pretty much our whole subforum. Still shows a bit of a focus toward the northwestern half of the state.

Yea dry air is definitely an inhibitor in this boundary type setup with the cold pressing. Otherwise if the low does in fact track to VA Beach like the GFS especially has suggested, that still is typically an okay track for the southern half of the area (Delmarva is ideal for C-PA). I feel some accumulating snow would find a way just across the M/D if it did that. A lot of the short/near term guidance take the low pressure off at the OBX, which probably would result in accumulating staying below the M/D line.

Haha that partial post above the post with the snow map… I see two trends in that screen capture lol.

Speaking of short/near term models. Here’s the 12z HREF for posterity. I know CTP utilizes it and pretty sure it was mentioned in the AFD this morning (not being much help at the time). It seems pretty clear across the model spectrum at this point that 8-12” or so is a pretty good possibility in the axis of heaviest snow. Gonna be important to keep an eye on surface low track. This model put this swath out with a surface low track hitting the coast at the OBX near Hatteras. GFS was a VA Beach track and Euro was pretty close to that too…big difference for the southern tier of our subforum.

Yea this Euro run is a snow bomb. I know everyone likes to be nit picky and be like cut the snowfall amounts in half and ground temps and blah blah blah but none of that matters the first week of January (or April) with rates like that. DC has like 8 hours of 1”+ an hour and that’s applying 10:1. The column becomes cold during this with -6 to -8ºC all the way down to 925mb. This probably becomes greater than 10:1, hence why I’m presenting the Kuchera while I try not to shed a tear. That would get the 6” line into York and Lancaster.

That late week system has looked good on everything that goes out that far and their ensembles not named the GFS op the last few runs, though the GEFS has looked like it’s started to support GFS op some with 6 and 12z today lessening it’s snow/QPF mean. Don’t really think fast flow is the issue, I mean this thing coming up tomorrow is in the same fast flow regime. It looks like GFS may be deeper with the mid-week feature over the Great Lakes that reinforces our cold and possibly sets the table for that event (something I mentioned was probably going to be a key for that late week threat). Also might be somewhat faster with the shortwave that would cause the 1/7 event. So could be why that particular model has been squashing it.

Hardly, unless you only looked at the GFS op tonight. New Euro’s coming in a bit high and tight for the LSV’s liking this run and best snowbands in western/central PA. This is very much still in play. I used 10:1 for that. The Kuchera makes that 6”+ swath a 10”+ one.. which is possible because the snowy side of that system is likely to have a cold column and good surface temps.

Track about the same on the 0z vs 18z Euro. Precip extent does sneak across the M/D line on the 0z getting an inch or so into southern York/Lancaster. Best snowfall axis about the same but big difference in top end with a more GFS-like 10”+ swath now (not as expansive as the GFS though).

The GFS has been pretty inconsistent with it the last model cycle or so. Going a little further back to yesterday’s 12z run, it was a full blown lakes cutter. The GEFS has shown it more consistently. The 0z still has a 2”+ mean over most of PA despite the complete miss on the op. 0z Canadian’s coming in with a nice 4-8” type snowfall statewide. The earlier 18z Euro ensemble that goes out to 144 and saw most of the event also was in good shape for a widespread snowfall. Still a medium range deal so I think it’s still looking good all things considered.

Progressive pattern was my big thing with this feature and it still is but I was not expecting the shortwave responsible for this to get stronger like it has. I expected a much less defined one in the wake of the current wave. There’s probably a cap at how far up this can get but I’ll eat the humble pie if the LSV does end up with a decent event. I already accepted sitting this one out in the cold in hopes of the 1/7 event after literally having it rain off an on the entire 6 days since it snowed Monday. But I’m still a snow weenie at heart too so this 1/3 one’s probably gonna reel me in just enough to hoping to see it get something up this way haha.

18z Euro v. 12z Euro, a jog north on extent with accumulating (1 inch or so into DC now) but fairly similar with amounts/heavy axis placement.

I mean swath-wise with the axis of heaviest snowfall is certainly a hat-tip toward the GFS when considering what the Euro/Canadian has. The 12z Canadian indicated a lot of heavy sleet where the heavy deform bands presumably would be in central/eastern VA. GFS still NW with it’s axis vs those two and very heavy with snowfall and the 18z GEFS largely backs it up it appears. The Euro/Canadian take is still a pretty big snowstorm for that area but 18z GFS evolution is a big ticket snowstorm for the Mid-Atlantic region. 12 and 18z NAM today has been straight up uninterested in any of this which I’d imagine is probably wrong to at least some degree considering the rest of the guidance suite and associated ensembles and the fairly robust shortwave in question even with limited amplification opportunities. So at any rate, obviously the middle of the road is the best way to approach this as there’s a lot of questions to resolve. If this indeed ends up a deeper wave and puts good precip into the Mid-Atlantic region, big question probably is going to be if there’s gonna be a changeover to overcome and how long it takes where biggest snow totals are being presented, which comes down to timing and how well the cold actually progresses. LSV shouldn’t have that problem by that time, but northern extent is now the big question for some in this subforum. I still say I don’t expect a lot if it does make it into the southern tier LSV, but we shall see. I’ve often looked at them but it is important to still pay attention to QPF maps, especially in fringe situations like the LSV is going to be possibly be positioned in for this 1/3 event.

Boy we’re really about to find out about the GFS’s short term prowess these days with a snowstorm on the line, especially the folks in Central VA. In the meantime the NAM should sue the GFS for copyright infringement of the term “NAM’ed”.

I wasn’t overly optimistic on the 1/3 system a few days ago and I still am not, though I’ll admit the door is open for our fringe folks on the southern tier to maybe get a period some light snow. It’s a nice vort on the 500mb but patterns quite progressive for this and there’s no interaction at all with the northern stream. I think this wave needed to come up faster on the heels of what we’re getting today for this to have had a chance at working well for our region, which would have required some thread the needle timing with the cold air coming in tomorrow. I have much higher optimism on this 1/7 event. Key feature for this appears the low that traverses the Lakes mid-week and refreshes the cold… setting the boundary this wave will run. Additionally, this feature may help lessen or take away the potential for this to cut. Seems like the GFS and Canadian ops today really press the cold after the mid week low and stuff the wave that potentially becomes our snowstorm (Canadian especially.. GFS wasn’t really that far off). 12z Euro sets it up perfect. 12z Euro and GFS ensembles as a mean seem to be angling more towards what the Euro op is showing. Ensemble comparison: Prob of 24 hr snowfall >1” Euro EPS v. GEFS