Western Pa / Pittsburgh area Winter Discussion ❄️☃️

[TimB]

41 minutes ago, MikeB_01 said:

Has to do with the data collection around the country. If you look at the observational soundings (balloon launches), most CWAs launch at 00z and 12z. This data is fed directly into the models runs at those times. Very few CWAs have launches at the 6z and 18z times. Only a few and in special circumstances will launch then.

 

So there is validity to the “0z and 12z are better” argument?

[dj3]

0z gfs run is probably the peak for mon/Tuesday. Overrunning and a perfectly squeezed primary into a coastal transfer. 

[RitualOfTheTrout]

14 minutes ago, TimB84 said:

So there is validity to the “0z and 12z are better” argument?

18z uses the 6 hour forecast from the 12z run as the initial data point, likewise 6z uses 00z 6 hour forecast for it's initialization where as 12z / 00z use fresh data from observations for the initialization. 

I thought though that the off hour runs get some new data, but I can't say for sure as it's been awhile since I looked into this and things may have changed.

[Ecanem]

Ugh.  In the bullseye of the gfs 5 days out. It’s a curse I tell you. 
 

 

[RitualOfTheTrout]

 

8 minutes ago, dj3 said:

0z gfs run is probably the peak for mon/Tuesday. Overrunning and a perfectly squeezed primary into a coastal transfer. 

Yeah that's a good look, given the speed hard to imagine it could get much better, hopefully we won't lose to much ground as we close in. I'm

[dj3]

1 minute ago, RitualOfTheTrout said:

Yeah that's a good look, given the speed hard to imagine it could get much better, hopefully we won't lose to much ground as we close in. 

It’s about to hit it us with the second wave also. This could be a run to save LOL.

ETA: probably still going to be messy on the second one but trending in the right direction 

 

[Rd9108]

5 minutes ago, Ecanem said:

Ugh.  In the bullseye of the gfs 5 days out. It’s a curse I tell you. 
 

 

Eh it starts Monday so more like 3-4 days. Regardless we know it's gonna change. 

[Burghblizz]

GFS is looking a bit like the Euro. Runs a first wave out on Monday. We get a decent shot of snow out of it.

That’s great, but here is the question. Does that work to erode the high a bit, and thus let the bigger storm ride north farther?

Maybe, maybe not. It’s a good run for Western PA overall, just something to watch as to it being a tad warmer. It’s a mess farther east. 

[Burghblizz]

[Rd9108]

Gfs has been pretty steady with this storm the past couple runs. Still like 16 more model suites to go. 

[north pgh]

Canadian a direct hit twice. Going to be a long weekend of tracking.

[MikeB_01]

I did a little digging into some of the soundings for the GFS run tonight. The graphic has mixed precip making it to the AGC/ Wash county line. Interestingly, though the graphic shows mix, the sounding would indicate snow --> not sure what he error is in the algorithm there. 

 

That being said, that warm nose is strong. This is going to be a tight one. Here is the sounding for 06z tue. 19° but damn does that temp get close to 32° at the 850 level. 

[SteelCity87]

46 minutes ago, north pgh said:

Canadian a direct hit twice. Going to be a long weekend of tracking

Early week and late week storm?

[Rd9108]

Looking at the Euro seems like it took a huge step back. 6z GFS looks about the same. 

[Ecanem]

45 minutes ago, Rd9108 said:

Looking at the Euro seems like it took a huge step back. 6z GFS looks about the same. 

In what way? Sure the overalL totals are a little lower but I never really thought we would get 12”

edit: for the gfs that is. I just loaded the euro and it’s wet on tuesday. 

[TimB]

1 hour ago, Ecanem said:

In what way? Sure the overalL totals are a little lower but I never really thought we would get 12”

edit: for the gfs that is. I just loaded the euro and it’s wet on tuesday. 

Euro is wet on Tuesday, GFS is wet on Thursday/Friday. What are the chances we get more rain than snow?

[Ahoff]

9 hours ago, Ecanem said:

Ugh.  In the bullseye of the gfs 5 days out. It’s a curse I tell you. 
 

 

Well technically we're under 5 days from the start.

[Ahoff]

I don't like the Euro.  It makes me nervous that it is the one showing ice and rain mostly, still time though.  GFS looks great.

But would the High to the north allow the low to cut like that?  We'll see I guess.

[TimB]

12 minutes ago, Ahoff said:

I don't like the Euro.  It makes me nervous that it is the one showing ice and rain mostly, still time though.  GFS looks great.

But would the High to the north allow the low to cut like that?  We'll see I guess.

But that’s the scary part. These models are ~4 days from the onset of precip and depicting completely different scenarios. Not just a little bit different, but completely out of phase with each other.

[Ahoff]

Some major things I'm seeing in Euro and GFS, I looked at both from the 0z run, since that is the common time I could find.

At hr. 96 the Euro has the L on the MS/AL line at the Gulf Coast.  I would think with a low in that spot the storm wouldn't cut as much, but not what is depicted.  GFS is just north of Atlanta.

At hr 102 the Euro is actually very close to the GFS at hr. 96, it's just throwing more warmth to our area.  GFS at the 102 has moved into Central NC.

Hr. 108 is the major divergent point, Euro rams the low just west of Wheeling.  GFS is off the Jersey Shore.  Quite a few Hundred miles.

The highs on the models look actually similar in placement.  Euro is stronger, so not really sure why it would cut if the GFS doesn't.  Maybe because High is too far east?

Current GFS-Para run (0z) is hybrid of GFS and Euro. drives low to central WV, then transfers to Chesapeake Bay.  CMC stays south of us, and all snow, goes from S. WV to off the Jersey Shore and then Cape Cod at hr. 108.  Icon is all snow, well of Jersey Shore.  NavGem is well off the coast

Consistency, at 108 on th 0z for today Euro as stated is west of Wheeling with the L.  12z yesterday it had the L just south of Charlotte for the same timestamp, with the prior shiot looking similare to today.  0z yesterday had the L near GA/SC border.  12z on 2/10 had the low in Atlanta.  So, the Euro was fairly consistent until this run.  Hopefully that's a one off and if corrects to where it was, if it's a trend it was a massive correction.

Consistency for the GFS: 0z today, L in central NC.  12z yesterday the L was in Charlotte.  0z yesterday, L near Raleigh.  12z on 2/10, L was in south central Ohio.  GFS has stayed consistently south the last few runs, but was Euro-esque before.  They seemingly flipped.  Does this mean GFS had the right idea and is getting lost, or the Euro went crazy for a run or two?  We'll see kind of interesting.

 

 

[CoraopolisWx]

32 minutes ago, Ahoff said:

I don't like the Euro.  It makes me nervous that it is the one showing ice and rain mostly, still time though.  GFS looks great.

But would the High to the north allow the low to cut like that?  We'll see I guess.

No doubt it's gonna be close. How much surge the 850's make is the key.

From what I've read on here, sometimes these highs aren't all built the same, with regards to how deep or shallow the below freezing column is.

[TimB]

7 minutes ago, Ahoff said:

Some major things I'm seeing in Euro and GFS, I looked at both from the 0z run, since that is the common time I could find.

At hr. 96 the Euro has the L on the MS/AL line at the Gulf Coast.  I would think with a low in that spot the storm wouldn't cut as much, but not what is depicted.  GFS is just north of Atlanta.

At hr 102 the Euro is actually very close to the GFS at hr. 96, it's just throwing more warmth to our area.  GFS at the 102 has moved into Central NC.

Hr. 108 is the major divergent point, Euro rams the low just west of Wheeling.  GFS is off the Jersey Shore.  Quite a few Hundred miles.

The highs on the models look actually similar in placement.  Euro is stronger, so not really sure why it would cut if the GFS doesn't.  Maybe because High is too far east?

Current GFS-Para run (0z) is hybrid of GFS and Euro. drives low to central WV, then transfers to Chesapeake Bay.  CMC stays south of us, and all snow, goes from S. WV to off the Jersey Shore and then Cape Cod at hr. 108.  Icon is all snow, well of Jersey Shore.  NavGem is well off the coast

Consistency, at 108 on th 0z for today Euro as stated is west of Wheeling with the L.  12z yesterday it had the L just south of Charlotte for the same timestamp, with the prior shiot looking similare to today.  0z yesterday had the L near GA/SC border.  12z on 2/10 had the low in Atlanta.  So, the Euro was fairly consistent until this run.  Hopefully that's a one off and if corrects to where it was, if it's a trend it was a massive correction.

Consistency for the GFS: 0z today, L in central NC.  12z yesterday the L was in Charlotte.  0z yesterday, L near Raleigh.  12z on 2/10, L was in south central Ohio.  GFS has stayed consistently south the last few runs, but was Euro-esque before.  They seemingly flipped.  Does this mean GFS had the right idea and is getting lost, or the Euro went crazy for a run or two?  We'll see kind of interesting.

 

 

The Euro did do this with our 2/9 storm 5 or 6 days before, suggesting the system would track way west and pump our temps up close to 50. That didn’t verify.

[Ahoff]

1 minute ago, TimB84 said:

The Euro did do this with our 2/9 storm 5 or 6 days before, suggesting the system would track way west and pump our temps up close to 50. That didn’t verify.

Yeah, I wish I kept better track of how each model performed.  Some people it seems know what every model did every day leading up to every storm in a season and previous seasons, lol.  So, I'm not sure what model is superior this year.  Hopefully, this is a wacky run.

[TimB]

10 minutes ago, Ahoff said:

Yeah, I wish I kept better track of how each model performed.  Some people it seems know what every model did every day leading up to every storm in a season and previous seasons, lol.  So, I'm not sure what model is superior this year.  Hopefully, this is a wacky run.

I can’t say I know what model has been superior, they’ve all struggled to get a handle on how this pattern will play out for really the entire month of February so far. I just remember there being a 50 degree swing from one run to the next on the Euro, going from a historic cold snap to temperatures well above freezing. But that was the first run that it picked up the 2/9 system, not several days after it had been painting the exact same picture as the GFS for a number of runs.

The Euro did beat the GFS significantly in recognizing that the brutal cold would not reach our area and we would instead lie in that active storm track most of the month.

And the GFS did try to give us that monster storm this coming Sunday for a run or two that no other model really bit on.

[Ahoff]

4 minutes ago, TimB84 said:

I can’t say I know what model has been superior, they’ve all struggled to get a handle on how this pattern will play out for really the entire month of February so far. I just remember there being a 50 degree swing from one run to the next on the Euro, going from a historic cold snap to temperatures well above freezing. But that was the first run that it picked up the 2/9 system, not several days after it had been painting the exact same picture as the GFS for a number of runs.

The Euro did beat the GFS significantly in recognizing that the brutal cold would not reach our area and we would instead lie in that active storm track most of the month.

Only after it flirted with the idea too, it had a couple -17 and -18 degree runs as well, lol.

[TimB]

5 minutes ago, Ahoff said:

Only after it flirted with the idea too, it had a couple -17 and -18 degree runs as well, lol.

True. It was the most recent model to predict that magnitude of cold. On that note, both models put us close to 0 after the Mon/Tues storm and the Euro puts us close to 0 after the Thurs/Fri storm. Para brings subzero cold Wed. AM.

[RitualOfTheTrout]

51 minutes ago, Ahoff said:

I don't like the Euro.  It makes me nervous that it is the one showing ice and rain mostly, still time though.  GFS looks great.

But would the High to the north allow the low to cut like that?  We'll see I guess.

I'm sure I'm going to oversimply or partially misstate something here, but an area of high pressure in and of itself will not necessarily "block" a storm from cutting into it. Now if it's strong enough and has a solid depth of cold air with it that will offer some resistance and will help to funnel cold air down into the storm possibly extending the amount of time an area stays frozen. The other thing to look at is how blocked the flow is, if you have a ball of low pressure stuck under a block at the 50/50 Longitude / Latitude (What some refer to as a 50/50 Low) that also helps slow the flow down so a high will have more staying power.

The other than that really matters though is to look at 500, to block a storm from cutting you want confluence and you want the trough to not go negative to far to the West. So in the 500mb map below, the green circle you can see a piece of energy swinging by pushing the height lines in a more West to East (Compressing the flow between that and the ridge in the SE), that would imply once a storm gets to that point it's going to feel pressure to either move in a more  Easterly direction or jump to the coast. The area circled in blue is the trough orientation, in this example its positive (height lines lean towards the right) This is indicative of a more progressive system still at that point and it would be less likely to cut and pump heights and subsequently flood us with warm air. As those lines become more straight up and down with a deepening storm, that's referred to neutral, and if they band to the left negative tilted trough. Also, pay attention to the colors, dark red would indicate there is a lot of energy in the trough, then do comparisons to previous runs to see if as we get closer in time there is more or less energy to discern a trend.

In a simplified way, just imagine those lines as like a roadway or path of least resistance, and that is the track a storm will want to take. Looking at this level of the atmosphere its really interesting and obvious how other down / upstream features will effect the track of a storm. 

[Burghblizz]

6 minutes ago, RitualOfTheTrout said:

I'm sure I'm going to oversimply or partially misstate something here, but an area of high pressure in and of itself will not necessarily "block" a storm from cutting into it. Now if it's strong enough and has a solid depth of cold air with it that will offer some resistance and will help to funnel cold air down into the storm possibly extending the amount of time an area stays frozen. The other thing to look at is how blocked the flow is, if you have a ball of low pressure stuck under a block at the 50/50 Longitude / Latitude (What some refer to as a 50/50 Low) that also helps slow the flow down so a high will have more staying power.

The other than that really matters though is to look at 500, to block a storm from cutting you want confluence and you want the trough to not go negative to far to the West. So in the 500mb map below, the green circle you can see a piece of energy swinging by pushing the height lines in a more West to East (Compressing the flow between that and the ridge in the SE), that would imply once a storm gets to that point it's going to feel pressure to either move in a more  Easterly direction or jump to the coast. The area circled in blue is the trough orientation, in this example its positive (height lines lean towards the right) This is indicative of a more progressive system still at that point and it would be less likely to cut and pump heights and subsequently flood us with warm air. As those lines become more straight up and down with a deepening storm, that's referred to neutral, and if they band to the left negative tilted trough. Also, pay attention to the colors, dark red would indicate there is a lot of energy in the trough, then do comparisons to previous runs to see if as we get closer in time there is more or less energy to discern a trend.

In a simplified way, just imagine those lines as like a roadway or path of least resistance, and that is the track a storm will want to take. Looking at this level of the atmosphere its really interesting and obvious how other down / upstream features will effect the track of a storm. 

Yeah, many times we are rooting for it to go negative as it helps to capture and keep a coastal storm tight to the coast or on the Piedmont.
 

Rooting more progressive here at least until it gets past this point  as depicted on the NAM. Taken literally, I think we would like hour 87.

 

[Ahoff]

Beautiful look on the NAM of course...hr. 84.

Rooting for the Weather Channel to win out they have Monday with 6-11" of snow.  Mostly overnight, and an additional inch on Tuesday.

[TimB]

Just now, Ahoff said:

Beautiful look on the NAM of course...hr. 84.

Rooting for the Weather Channel to win out they have Monday with 6-11" of snow.  Mostly overnight, and an additional inch on Tuesday.

Interestingly, TWC is liking the later week storm for 6-12” over a 36+ hour period.