Feb 6-7 storm?

[Snownado]

What happened to the 1-2" in Indy ? Did it disappear ?

[michsnowfreak]

15 hours ago, cyclone77 said:

Winding down here, with 0.8" as the total.  LSR seems pretty low, as the snow is very sugary as Josh would say.  Kind of a disappointment, but still a nice little refresher and always nice to see it snow during the daytime.  

Yep, we got a 0.4" of sugar here on 0.03" liquid. Gave a glitter to the snowpack. Josh's snowfall chart:

wet snow or slushy snow (mild out)

dense snow (mild out, similar to wet snow but no melting of any kind on pavement)

sandy or sugary snow (cold but low ratio snow due to small flakes)

powder (my favorite if I had to pick. usually 12-14:1 ratio)

fluff (15-20:1 ratio snow)

air fluff (20+ : 1 ratio snow)

 

[cyclone77]

2 minutes ago, michsnowfreak said:

Yep, we got a 0.4" of sugar here on 0.03" liquid. Gave a glitter to the snowpack. Josh's snowfall chart:

wet snow or slushy snow (mild out)

dense snow (mild out, similar to wet snow but no melting of any kind on pavement)

sandy or sugary snow (cold but low ratio snow due to small flakes)

powder (my favorite if I had to pick. usually 12-14:1 ratio)

fluff (15-20:1 ratio snow)

air fluff (20+ : 1 ratio snow)

 

and feathers, the semi-rare 30:1.  Basically no resistance while walking through several inches of it.

[Chicago Storm]

5 hours ago, purduewx80 said:

O’Hare came in w a 10:1 ratio too (0.7” on 0.07” liquid). 
 

The observer near Midway had 0.8” on 0.05” liquid (16:1). 

Not surprisingly 0.8" of snow off 0.07" liquid at RFD.

[Chicago Storm]

57 minutes ago, StormChaser4Life said:

Got like 1.5-2in here. Definitely think the ratios weren't as good here. Snow was like pixie dust a while. Once we got into a good band towards the last few hours of snow, flake size improved but was a little too late. 

15:1 ratio officially at PIA.

1.8" of snow off 0.12" of liquid.

[michsnowfreak]

Just now, cyclone77 said:

and feathers, the semi-rare 30:1.  Basically no resistance while walking through several inches of it.

yes! good one to add.

 

The piles that we have from the 4.2" deluge of dense snow the other night are probably equivalent to what you would see with a foot plus of Lake effect snow. There are so many different kinds of snows it seems that as fun as it is to look at snow maps, whether looking at 10:1ratio or kuchera, really a lot of judgement needs to go into an accurate forecast. it's not as simple as temps+qpf.  Usually evens out over the course of a Winter but it almost seems not fair that you can pour snow in November and you get like 1" on 0.25" of liquid, then you can get a fluffy Lake effect band will you get 1" and 0.03" of liquid.

[Radtechwxman]

1 hour ago, Chicago Storm said:

15:1 ratio officially at PIA.

1.8" of snow off 0.12" of liquid.

Definitely lower than I expected. Less qpf and lower ratios. Better ratios were in that weenie band just to my nw. Got the tail end of it. We actually saturated pretty rapidly. System must of came in drier than originally thought. 

[WestMichigan]

3 hours ago, michsnowfreak said:

Yep, we got a 0.4" of sugar here on 0.03" liquid. Gave a glitter to the snowpack. Josh's snowfall chart:

wet snow or slushy snow (mild out)

dense snow (mild out, similar to wet snow but no melting of any kind on pavement)

sandy or sugary snow (cold but low ratio snow due to small flakes)

powder (my favorite if I had to pick. usually 12-14:1 ratio)

fluff (15-20:1 ratio snow)

air fluff (20+ : 1 ratio snow)

 

About 3.5” over here yesterday through last night. Nice to see winter showing up. 

[frostfern]

10 hours ago, michsnowfreak said:

yes! good one to add.

 

The piles that we have from the 4.2" deluge of dense snow the other night are probably equivalent to what you would see with a foot plus of Lake effect snow. There are so many different kinds of snows it seems that as fun as it is to look at snow maps, whether looking at 10:1ratio or kuchera, really a lot of judgement needs to go into an accurate forecast. it's not as simple as temps+qpf.  Usually evens out over the course of a Winter but it almost seems not fair that you can pour snow in November and you get like 1" on 0.25" of liquid, then you can get a fluffy Lake effect band will you get 1" and 0.03" of liquid.

Yea.  It's way more complicated than temperature.  The highest ratios seem to be from shallow clouds with a cloud-base dewpoint around 10-15 degrees.  When dewpoints at the cloud base are in the single digits or lower the snow gets more dense again as you have mostly diamond dust plates.  It's lighter than a wet snow, but denser than fluff.  Lots of drifting decreases the ratio as well because the aggregate flakes get broken up into individual crystals and land flat.  Snow that has blown off the roof can be especially dense even when it's cold.  Wind-sculpted cornices can be rock-hard and exceptionally dense, probably because the loose flakes all blow away leaving very dense semi-fused crystals behind.

Also, snow that forms in really deep strong updrafts is denser due to rimed flakes.  Light-intensity lake-effect is more fluffy than the stuff that falls from really intense bands.  It seems a bit of a nonlinear curve.  Very weak vertical motion will produce mostly plates due to supersaturation not being great enough for dendrites.  Moderate vertical motion will produce big dendrite flakes that form aggregates and really boost the fluff factor.  Extreme vertical motion leads to rimed flakes and eventually graupel, which is dense.