January 24-26: Miracle or Mirage Thread 2

[TSG]

15 minutes ago, WxUSAF said:

Tomer Burg posted elsewhere that it apparently is a know euro problem with ZR vs sleet. I think very little ZR for the metro areas. Maybe FZDZ at the very end.

I think it's having issues with snow vs sleet/zr as well? Look at this 6z sounding over DC @ 18z Sun.. maps say zr. That looks like snow to me unless there's a sneaky warm layer in there

 

[Scarlet Pimpernel]

2 minutes ago, NorthArlington101 said:

LWX also pretty aggro. We'll see

 

2 minutes ago, WxUSAF said:

LWX just updated event total snow. 10” DC, 11” Baltimore, 11” CHO, 9” EZF, 14” FDK and HGR.

Wonder if they're including an estimated sleet accumulation on top of whatever snow in that total, that map goes through Sunday evening.

[hstorm]

1 minute ago, Scarlet Pimpernel said:

 

Wonder if they're including an estimated sleet accumulation on top of whatever snow in that total, that map goes through Sunday evening.

I have always assumed it counts sleet because sleet counts as snow (for reporting purposes)

[Eskimo Joe]

5 minutes ago, WxUSAF said:

LWX just updated event total snow. 10” DC, 11” Baltimore, 11” CHO, 9” EZF, 14” FDK and HGR.

 that's aggressive

[H2O]

7 minutes ago, WxUSAF said:

LWX just updated event total snow. 10” DC, 11” Baltimore, 11” CHO, 9” EZF, 14” FDK and HGR.

thats ballsy.  But I like it.  They have to be factoring in some of the slightly colder solutions

[Terpeast]

2 minutes ago, Eskimo Joe said:

 that's aggressive

They may be going with a blend of the Euro and GFS. Which isn't entirely unreasonable, just not something we would run with ourselves.

[GATECH]

I like it better when they play catch-up…

[Nomz]

If you told me a week ago we'd get 8 inches in DC, I'd be happy. So I'm happy.

[MN Transplant]

6 minutes ago, Scarlet Pimpernel said:

 

Wonder if they're including an estimated sleet accumulation on top of whatever snow in that total, that map goes through Sunday evening.

Almost certainly.  Sleet counts as accumulation.

[GATECH]

And I mean this storm is coming on the exact 26th anniversary of the greatest game of catch-up in history…Jan 25, 2000

[adelphi_sky]

9 minutes ago, TSSN+ said:

Must be riding the gfs haha 

That looks historically accurate. more N&W than DC and burbs. 

[TSSN+]

1 minute ago, Terpeast said:

They may be going with a blend of the Euro and GFS. Which isn't entirely unreasonable, just not something we would run with ourselves.

Who let Ji onto LWX’s snow map making computer lol. Ya right if he was on there the map would be maxed out. 

[AmericanWxFreak]

1 minute ago, MN Transplant said:

Almost certainly.  Sleet counts as accumulation.

The map is titled "Snow Accumulation" however. 

[TSSN+]

Just now, AmericanWxFreak said:

The map is titled "Snow Accumulation" however. 

Sleet is counted as “snow”

[EHoffman]

Just now, AmericanWxFreak said:

The map is titled "Snow Accumulation" however. 

Yeah but NWS counts sleet accumulation as snow accumulation.

[adelphi_sky]

Just now, EHoffman said:

Yeah but NWS counts sleet accumulation as snow accumulation.

I feel like they should have a 3D cross section of P-Type depth like 10" of snow with 2" of sleet on top. That would help visualize it better.

[Nomz]

4 minutes ago, Nomz said:

If you told me a week ago we'd get 8 inches in DC, I'd be happy. So I'm happy.

... it is sickening that PA/NYC/SNE are robbing us though

[WxUSAF]

7 minutes ago, Eskimo Joe said:

 that's aggressive

 

5 minutes ago, H2O said:

thats ballsy.  But I like it.  They have to be factoring in some of the slightly colder solutions

If you’re going off just this 12z suite, maybe a bit? If you’re including some 6z and 0z in your super ensemble, maybe not? Think that’s about spot on what 6z euro had except for maybe southernmost zones?

And yeah, 1” of sleet seems quite possible on top of snow.

[Scarlet Pimpernel]

7 minutes ago, hstorm said:

I have always assumed it counts sleet because sleet counts as snow (for reporting purposes)

 

3 minutes ago, MN Transplant said:

Almost certainly.  Sleet counts as accumulation.

That's what I thought and was my understanding.  So you might figure (for DC) ~8" of pure snow plus another couple inches of snow/sleet after that, perhaps.  Or something on that order.  The point-click forecast is currently going 5-9" overnight Saturday and then snow/sleet Sunday (with no estimate yet on amount).

[snowmagnet]

I hate this part… waiting for the storm.  Back in the 2010’s, the Euro used to back  off higher total as we got closer to the event, but the earlier numbers were accurate. That happened several times in 2013-2015. We will see.. They rarely end up as forecasted. 

[WEATHER53]

1 hour ago, stormtracker said:

If we can make it past 18z with snow, I'd be ecstatic. 

And I see that diamond shape taking form off coast so that should pull cold air back east 

[jayyy]

Pretty reasonable NWS map honestly. Sure, maybe totals along 95 are a bit risky given the uncertainty around track, but most areas look pretty much in line with the consensus of guidance - including dc and Baltimore.

[Jebman]

2 minutes ago, WxUSAF said:

 

If you’re going off just this 12z suite, maybe a bit? If you’re including some 6z and 0z in your super ensemble, maybe not? Think that’s about spot on what 6z euro had except for maybe southernmost zones?

And yeah, 1” of sleet seems quite possible on top of snow.

Sleetpack on top of snow? That is not going anywhere any time soon.

[mappy]

19 minutes ago, TSSN+ said:

CTP snow map is ridiculous but hey I’ll enjoy it for now till it drops like 8” later lol 

 

I actually don’t think it’s that bad. May not sleet as much once you north of the line compared to my backyard 

[Nomz]

Sleet falls at around 3:1 right? Using Euro's QPF of 1.4 and conservatively guessing 1/2 of that to fall as snow, 1/2 as sleet; 0.7*10+.7*3 = 9.1 inches total accumulation. I'll take that as a baseline any day.

[MillvilleWx]

17 minutes ago, NorthArlington101 said:

LWX also pretty aggro. We'll see

That’s not a terrible map, but it doesn’t include the microclimate types and also is smoothed compared to what the eventual QPF distribution will eventually be in the end. I can see the northern and southern edges adjusting to showing a larger spread and tighter gradient by game time, but I don’t see this is a terrible forecast upfront. Bit aggressive, but we have time. 

[MillvilleWx]

Also yes, that map likely includes sleet as well since that’s how it goes in the record for the daily measurements. 

[WxUSAF]

1 minute ago, Nomz said:

Sleet falls at around 3:1 right? Using Euro's QPF of 1.4 and conservatively guessing 1/2 of that to fall as snow, 1/2 as sleet; 0.7*10+.7*3 = 9.1 inches total accumulation. I'll take that as a baseline any day.

Yes, 3:1 ratio is assumed for sleet

1 minute ago, MillvilleWx said:

That’s not a terrible map, but it doesn’t include the microclimate types and also is smoothed compared to what the eventual QPF distribution will eventually be in the end. I can see the northern and southern edges adjusting to showing a larger spread and tighter gradient by game time, but I don’t see this is a terrible forecast upfront. Bit aggressive, but we have time. 

Yeah, going to be banding and ratio variations that change things. 

[Pityflakes]

4 minutes ago, Scarlet Pimpernel said:

 

That's what I thought and was my understanding.  So you might figure (for DC) ~8" of pure snow plus another couple inches of snow/sleet after that, perhaps.  Or something on that order.  The point-click forecast is currently going 5-9" overnight Saturday and then snow/sleet Sunday (with no estimate yet on amount).

Accumulation yes, but would sleet actually add to snow depth (which is all anyone who isn't a weirdo like us will pay attention to).  Sleet usually doesn't just sit nicely "on top" of fresh powdery snow but rather it mixes in with it and even compacts it. 

[Maestrobjwa]

1 minute ago, MillvilleWx said:

Also yes, that map likely includes sleet as well since that’s how it goes in the record for the daily measurements. 

Why does sleet make into daily snowfall measurements, anyway? I mean it's literally not snow, lol