TheClimateChanger

12Z HRRR wasn't too dissimilar. I used the actual modeled ratios for this map, which were less than both the 10:1 and Kuchera maps for the ridges. And less than the 10:1 ratio map, but slightly greater than the Kuchera map for the immediate metro. Pretty much in line with what I said above (which admittedly was more conservative than the NAM 3K since I had looked at the full suite of modeling before posting). Little if any downtown, but does show up to an inch in western Allegheny and up to 2" in northern Allegheny. With again the best chances of 2"+ being from Butler County northeast. Significantly less for the ridges, but still shows up to a foot in eastern Tucker (the Kuchera and 10:1 maps both showed up to 14" in eastern Tucker).

Key takeaway is this will be heavily elevation dependent. Might be difficult to get any accumulation downtown, while some of the more elevated neighborhoods might pick up a half inch. Taken literally, some of the global models do have a few inches in the city but I'd lean towards the mesoscale modeling in this situation. The official observation site will probably see some accumulating snow later, maybe 0.5-1.5 inches. Best chance of 2"+ looks to be in the northeastern parts of the area - northern Butler, Armstrong, Indiana, Venango, Forest, Clarion and Jefferson Counties. The higher totals to the north are partly a function of elevation, and partly a function of the fact that the precipitation lingers longer there into the evening and overnight. The ridges could see much more than the official forecast if the modeling is correct.

Interestingly the NAM 3K is showing nearly 30" in parts of Tucker County, while they are under a WWA for up to 4 inches. Not much for Pittsburgh city on the Kuchera ratio map, although that's a bit misleading as that is one of the lowest numbers in the metro area due to elevation and urban heat island. The numbers are placed right over the cities and not the airport locations where the obs are taken. Most places are shown in the 1-2" range, including around the airport. More to the northeast where the precipitation lasts longer after the changeover to snow. This is the Kuchera map which generally is less than the 10:1 map, although it might be a bit more in some of the ridge locations.

I’m up in northwestern Pennsylvania (near Clarion) this morning, and there was about a quarter to a half inch of snow accumulation on some surfaces this morning.

Canadian looks the best with 6"+ northeast of the city on 10:1 ratio. However, the actual accumulation might be less.

I was looking at old photos, and we had an inch or two of wet snow last year on April 21. Also had snow showers and a slight dusting on some elevated surfaces in 2020 on May 9th. Looks like a good chance of some late season accumulating snowfall next week.

All models seem to be on board for some possible accumulating snowfall next week. Euro, UKMet, and Canadian all have 3-5 inches on 10:1, but the Kuchera ratios are lower with an inch, maybe two in spots. GFS less, but maybe still a coating to a half inch.

Lock it in gentlemen.

Oh yeah, this would be a doozy.

Only 300+ hours away...

Euro holding out hope for one more snow storm, especially north.

Warm day today, but only one record in the region. The high temperature at Wheeling reached 79 degrees, besting the previous record set in 1910, 1936 & 1946 by one degree. A couple other sites were within a few degrees of the records, but Pittsburgh wasn't particularly close since it was a handful of degrees cooler than places to the south and west and the existing record was a lofty 82.

I do recall a couple earlier in the winter along the I-80 corridor. NWS PBZ doesn't seem too keen on them - maybe because of the EAS activation? The ones I recall seeing them issue were near the interstate, so maybe they prefer to limit them to particularly dangerous interstate corridors?

Geez. The NWS in State College really loves their snow squall warnings. It's like the entire CWA at one point for just some scattered heavier cells.

Nice squall moving through here now, coating all surfaces. Actually looks to be more intense to the southwest where there's some returns in excess of 40 dbz.

Snowing heavily here. About an inch on the ground, but easily inch per hour rates at the moment.

Intense squall near I-76 & I-376, south of New Castle.

Wow. Very heavy snow here. Looks to be a couple of inches. Must be snowing at several inches per hour.

Agreed. Read my post at the time. I would also disagree that the models supported 3-6" by 00z last evening. The consensus was more like 5-7 inches. The GFS, which I posted in this thread, showed 8.3 inches for Pittsburgh. But I thought it looked pretty clear that we would easily pass the low end of that range by like 2 am, and be pushing the high end by 4-5 am unless the snow started to fizzle out. I mean there was already 2" or so by 1 am, with what looked to be an absolute monster of a band from near Zanesville to Clarion. 40+ dbz were showing up in Beaver County. And snowfall rates under the lighter colors were already approaching an inch per hour, so it was obvious there would be some 2" per hour rates under that mega band.

What the heck? How has the advisory still not been upgraded to a warning?

I'm in Pittsburgh this weekend. I thought for sure I'd wake up this morning to find the WWA had been upgraded to a warning, when I looked out the window and there was still heavy snow falling. How much snow has fallen?

Looking at the 0z modeling, looks like consensus is 6 or 7 inches for most of SW PA. Think we will end up with low end warning totals. But who knows - if the GFS is right, Waynesburg might be pushing a foot.

00z GFS has 8.3 inches. Nowcasting and observation time. Looking at radar tonight, this looks pretty believable.

KYNG 120451Z 29007KT 3/4SM -SN BR OVC007 M02/M04 A2982 RMK AO2 SLP106 SNINCR 1/2 P0010 T10221039 401111039 RVRNO $ METAR from 11:51 pm at YNG shows 1" in the last hour, with 2" already on the ground there. Judging by radar over the past 45 minutes, I would expect them to report another inch with the upcoming METAR. I think they were only expected to get 2-4 inches. Looks to be heavier than expected. Wonder if the NWS will upgrade to a warning?

It's weird how most of the modeling has us getting just as much, if not more, than Central PA. Yet those areas are under a warning, and we are under an advisory.