MAG5035

Kuchera indicates the event is <10:1 in PA east of the Alleghenies ( central counties and LSV), a probable outcome given the changover scenario the Euro presents. A rapid temp drop in the column post front that allows a quick change to snow BUT the best precip ends before much colder air aloft arrives that would boost snow growth/ratios. Surface temps also fall from the 50s to near or just below freezing during the event (marginal but sufficient to accumulate with higher precip rates).

Euro is definitely much more pronounced with the vigorous shortwave and deeper with the surface low that runs the frontal boundary and enhances the the precipitation shield in C-PA post frontal passage. Modeling has been pretty persistent on some kind of an attempted changeover across at least some of PA the last several runs having this system with a sharp cold frontal passage. I think this scenario probably favors laurels and central counties more but the Euro solution does show how it could snow for most in here. The low develops along the boundary in VA and moves into central NJ (996mb at that point). GFS is trying to do the same thing but just isn’t as amplified as the Euro. Definitely intriguing, the range for this system isn’t really super far out (~D5).

Some occasional flurries/light snow here as well. PBZ radar indicates a wave of steadier snow that looks to get into the Laurels and perhaps some of the central counties as the afternoon wears on.

There’s definitely an opportunity to be had for the system progged near mid week next week. Coming on the heels of the stronger Sun/Mon system that resets the cold for a few days and a pretty decent -NAO block, there’s a good chance this northern branch feature is forced to track it’s low below PA.. which is a good start to getting any kind of meaningful flakes beyond western PA and the Laurels into the Sus Valley when it comes to clippers/clipper-like systems. Most modeling and ensembles have this feature, so strength and track of the feature are going to be the big thing. Today’s 12z GFS version is definitely more ideal, having a more defined and stronger surface low that tracks under PA which yields a better snow swath. A weaker feature going south of PA would still have some of the same issues with precip surviving east of the Alleghenies. A stronger one like the 12z GFS would establish some Atlantic fetch with the low hitting the coast, maintaining a swath into the Sus Valley and/or points south of there.

I’m not home currently but clearly the first measurable fell at the house this morning.

I probably slept through any pingers that may have fallen first thing this morning, but I may not have gotten any at all. Temp briefly was around freezing before midnight and hovered there til about 2am when a pretty good southerly breeze mixed down and kept temps in the mid 30s through precip arrival with no drop. Still a raw 35ºF with moderate rain. Wind shift and temp change highlighted (approx 140am) So now the race is on to see how big of a much needed rain event we get today. Most modeling has things in the 1.5-2” range in Central/Sus Valley for this event today/tonight.

Advisories were issued earlier this morning in the Laurels counties for mix/glaze of freezing rain (up to a tenth ice in the adjacent western MD counties). A larger portion of C-PA (likely the AOO-UNV-IPT corridor into NE PA) probably sees an initial period of wintry mix when the main precip arrives tomorrow morning given a pretty strong, though retreating high pressure over New England providing a CAD setup. High res guidance like the HRRR and that newer Rapid Refresh (RRFS) are more robust in cooling the 850mb layer on precip arrival and showing more frozen p-type (sleet and even snow). 3k NAM does show a bit of the same with regards to 850mb but shows freezing rain as a more dominant mix type. Reality is probably somewhere in between, with a better chance of a longer period of frozen the further north into PA one goes and biggest ZR impacts on the Laurel’s ridges and some of the adjacent ridges in the middle of the state. Could be interesting to see if advisories end up being warranted a bit further into the central counties. As noted by CTP, surface and road temps are likely to be quite marginal for impacts. A period of heavier mixed (esp sleet) could change that a bit.

Same down here. A bit more on the roofs, decks, car tops, etc than the grass which has a light dusting. First deck pic of the season haha

It’s been awhile since I’ve gotten a post on here… summer and fall are usually pretty busy for me. But I’ll be getting back to posting more regularly again. Certainly can’t miss possibly having some first flakes to observe overnight. Been watching the band of precip in western PA getting closer. It’s mostly clear currently and temp/dewpoint has fallen back to 32/29ºF.

Good bit of discrete cellular stuff firing from the ridge and valley eastward in the corridor of PA where the sun really came out this afternoon. Parameters (bulk shear/BRN) are very favorable for such things in all of C-PA today. Helicity values aren’t super noteworthy but they aren’t zero either, and that coupled with the best CAPEs being right up the whole Sus Valley currently means an area of 1-2 EHI values. Spin-ups are definitely possible just about anywhere. Tornado warnings now in northern Lycoming with a pair of decent looking couplets on BGM radar. The cell previously responsible for the tor warning in State College still looks pretty strong as it heads toward Sunbury. Everything severe is on the table today (esp severe wind) but I think the tornado/hail threat probably maximizes with the discrete stuff developing up front. This likely switches to a more clustered and/or linear type deal as we get into the late afternoon/ early evening and all those storms traversing WV/western MD and the Pa southern tier push into the Sus Valley. Of particular note there is the solidifying line from Bedford/Fulton south into MD/WV.

1.09” of much need rain here today, it’s a start.

After doing a rare June perusing of the models and discovering that there is an HRRR cross section smoke forecast, MDT looks to see a rapid deterioration within the next hour or so according to that (or perhaps right now-ish per JNS’s ob), which is supported by the general motion observed on the visible satellite imagery. Also want to note in the previous post the station obs plots in the satellite imagery. Another really anomalous part of this setup aside from the severity of the Canadian wildfires themselves is the major North American blocking pattern that is directly discharging Canadian air via due northerly flow.. which is why we’re in the crosshairs of all this smoke in the first place. Dew points are in the low to mid 30s across the commonwealth, occasionally even in the upper 20s at some PA sites this afternoon… something CTP noted last night in their disco as practically unheard of for June around here. PWAT map is another example of how dry the airmass is.

NE PA/NJ/NYC/LI is definitely where the worst of the smoke is currently, as evidenced by the visible satellite as well as the AQI maps.

The closest cell around here earlier this afternoon that mainly moved through Cambria County delivered some rain drops but not enough to register measurable on the rain gauge. Last measurable was May 20 (0.17”) and total last 30 days is 0.7”.

The near 4800’ peak just south of Canaan Valley State Park, WV (aka Mount Porte Crayon) doing it’s best Mammoth Mountain impression on the zones. This is the kind of setup (prolonged post storm cyclonic flow upslope event) that has been missing quite often for what seems like the last 5+ winters and is a prime driver in those snow departure maps that were shared around during the winter such as this one below showing one of the biggest departures anywhere in the eastern US (inch wise and also percentage of average) in these very areas. This setup occurring in the middle of winter would have likely yielded a long duration 1-2’ type upslope event just in the Laurel’s at their elevations. I know one of these maps were floating around that incorporated the last few winters back to 19/20 but it’s the same general theme for the Laurel’s/Alleghenies. These type of upslope events via this setup are a major part of what gets the higher elevations and ski resorts of that region their high snow averages (>150”).