Burghblizz

03Z RAP depiction is in the north camp

6 hours ago, Rd9108 said:

I'll take some hrpes 

 

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

13 minutes ago, Mailman said:

Seems like clippers tend to overachieve around these parts.

South of town looking good. 

6 hours ago, jwilson said:

Yep, really a function in the change of the confluence up north. 

This is from 0Z Saturday when it looked like the storm could have driven north of us.  Here you can see the northern stream is pretty flat and not particularly intense (area across Northern Michigan and Wisconsin), while our s/w of relevance is relatively spread and unaffected.

 

And then this is 12Z today.  Suddenly you have a bit of a notch developing in the wavelengths (stronger confluence), and it's also pressing down more with less of a West to East, flat orientation.  It's exerting more influence, overall.

Our area of relevance is more compressed, too, because of those NS changes.  Most of the energy is confined to a SE quadrant.  Precip shield cannot extend further to the NW away from that vorticity.

 

Manipulating a system like this creates your intense and compact deformation bands, but it limits the AOI of the storm.  Enough to generate those crazy gradients.

I think part of the problem lately is that NS moving so fast anymore and with it constantly dropping s/w after s/w, we're having more trouble timing things properly.  It feels like our only hope is to get the NS to phase in and give us something bigger while hoping we have some kind of block in place to prevent a storm from progressing north unimpeded.  It seems we can't just run a developed southern stream event without interference.  This is something more akin to Nina behavior, too.

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. 

2 minutes ago, TimB said:

Imagine a scenario where you and your wife haven’t, well, you know, for two years. You elaborately prepare a fancy date night, buy her a beautiful bouquet of flowers, take her out to a nice restaurant, order and drink a bottle of the finest wine on the menu, then come home and hit the sack. All of a sudden, just as you’re getting ready to do the deed, your drunken neighbor barges through the front door thinking he’s at his house but he’s at yours. That’s what happened with this storm.

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. 
 

1 hour ago, jwilson said:

On the bright side, at least it was relatively easy to avoid investment into this storm.  Long range it looked like a cutter, then it got borderline for 48 hours but never really looked right, to suppressed mode in another 12 hours.

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

5 minutes ago, Itstrainingtime said:

Many times. One of the biggest fails in the 2000s was 12/26/2010. That was the storm that NYC got like 30" and we had flurries.

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

4 minutes ago, Superstorm said:

Of course because I am at my Connecticut house it wants to trend south.


.

Sittin pretty

18 minutes ago, Rd9108 said:

Lol this is gonna miss south 

 

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. 

18 minutes ago, TheClimateChanger said:

This is true. When I noted we haven’t had a 12” calendar day since 1994, I was playing around on xMacis with other locations, and Dayton has only ever had one day with 12” or more (and only barely) in 1978. I think warning criteria might be 4” there, but they are even worse for big storm climatology. Same deal with Columbus where I think warning criteria is the same as Pittsburgh. 

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. 

19 minutes ago, TimB said:

Outside of lake enhancement in NW flow, we have upper south/lower midwest snow climo but northeast advisory/warning criteria.

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. 

1 hour ago, Rd9108 said:

UK continues to be south of other guidance 

 

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. 

7 minutes ago, north pgh said:

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

26 minutes ago, Rd9108 said:

3k is a lot warmer though. I guess it may actually come down to nowcasting.

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. 

9 minutes ago, Rd9108 said:

3k is a lot warmer though. I guess it may actually come down to nowcasting.

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

6 minutes ago, Rd9108 said:

I'm gonna laugh if the gfs decides to come back south.

It’s certainly shifted south away from us enough times