Burghblizz

03Z RAP depiction is in the north camp

Probably out to lunch with the totals, but that banding is interesting. Maybe some localized jackpot areas.

South of town looking good.

Great call outs. It’s easy to look at the surface and where the precip is depicted, but it’s the upper levels that drives it.

I’ve lived that scenario(figuratively), and this isn’t quite that. Dec 2000 and March 2001 in Harrisburg, I lost 3’ of predicted snow at nowcast time. Some of our WTODs had that vibe too This one always had red flags. I spent a lot of time on it because the modeling was so interesting and would have been a fun threading of the needle.

The funny thing is we got a rare SE shift, just the precip seemed to vanish on the NW side. Crazy

You mean 2000? I was in Harrisburg at the time. Sunny skies.

Sittin pretty

Euro isn’t necessarily south like the NAM - it’s just a touch too warm in changing over the intial slug of moisture. It’s still close to being decent.

Calendar day is misleading. The 2 15”+ storms after 94 straddled calendar days. 2.5 and 2.6 of 2010 got 10+” each day I think. Also, most of us got real close to a foot 12.20 during the same day. I also got 13” in 12.03 (living in Penn Hills) during a single calendar day. Official total fell short, but eastern AGC got walloped in about 8 hours. We don’t always knock those out of the park, but they get a lot leaner as you head southwest down the Ohio river.

The average snow here is substantially more, but the big storm frequency is more than places to the south and west. It isn’t just the lake enhancement. Some of you guys are always looking to the ridges, the snow belt, and New England and saying woe is us. But we get substantially more synomptic snow than places to the south and places at this latitude to the west. So the criteria is appropriate even if the last 2 years have sucked.

GFS another a tick better.

Congrats Morgantown I guess…

With all the uncertainty, let’s go with a blend for now

I guess I’m right on their 3” line- but honestly this is easily the most nowcast event of the year. The NAM also looks like it’s going to slide a little too far SE, but the GFS will be along shortly with it’s too far NW solution.

I think that’s the UK with the legend off as well. I think that light blue is really 2-4 not 4-6 (and so on)

The NWS discussion from yesterday said something to the effect that the eventual forecast might be more of a “middle ground” as opposed to the “most likely”. I’m not sure if that spread has closed that much in the last 24 hours. I’d probably put up something like “2-5 inches, but possibly less to the south and in lower elevations where there could be more rain”. When we talk elevation in this area, forecasters love to just say ridges versus non ridges. In reality it’s more nuanced with borderline P types. I think you’ll see some differences in the metro area between 800’ and 1200’

GFS looks like it might suck slightly less

The NWS has a HWO for Butler, Armstrong, Lawrence counties, noting that an advisory or warning might be needed in the next 36 hours. They noted too much uncertainty for right now. Thats fair and is a better strategy than CTPs “WSW kind of” strategy.I bet they are waiting for the rest of 12Z to make a call for watches for the northern metro area. I think they wait on AGC regardless, and add it if things trend well by tonight. Just too many red flags still.

Looks like a more realistic depiction of the NAM. Totals moderated a bit, and scaled way back in the Mon valley.

The other interesting thing is that it also has a different orientation of the precip shield. Has precip into NW PA, where 12k is dry. In upstate NY, you have some areas that have 12+, but zero in the 12k. Not sure that is too common. I would expect the differences to be more in micro details. Not sure I understand why that would be the case, but the models can’t even agree with themselves.

The thermals really create the boom or bust scenario. Probably more of a tapered look to totals if we were just worried about precip. I do feel a little better about middle of the night/early morning in February versus if it were middle of the day in March.

12Z NAM 10:1 strip of 12+ just for fun. I think we would gladly take the old “cut in half rule” here:

NAM not giving up - in fact its better for SW PA

It’s certainly shifted south away from us enough times