January 24-26: Miracle or Mirage OBS Thread!

[eyewall]

8 hours ago, Jebman said:

I am very happy you are okay. You'll get the windshield fixed, but the most important thing is you are okay.

Thank you and yep about to go to the dealer for when they open.

[MN Transplant]

12 hours ago, Roger Smith said:

DCA reported 1.99" liquid and 6.9" snow. If I'm generous and say .09" of that was freezing drizzle (probably an overestimate) then their snow report equals real snow plus sleet at some possible-to-calculate ratio after an assumption is made on the snowfall to liquid conversion. I will assume 10:1 in my calculation that follows.

So let's say 5" real snow, then we have

5.0 + 1.40*(ratio/10) = 6.9

That reduces to 1.40*(ratio/10) = 1.9

and makes ratio/10 = .21, in other words a 2.1 :  1.0  ratio. Sleet ratios are often quoted at 3:1. 

For 3:1 to be correct, then snow at 10:1 is 2.7" .. that is clearly a low estimate based on regional reports.

So either this was very watery sleet or very underestimated sleet. I would guess what really happened is that 3" of sleet pounded 6" of snow down to 4 inches and sat on top giving 7 inches.  

Roger - my sleet was 2:1

[MN Transplant]

13 hours ago, WEATHER53 said:

I can’t answer for right there at their  thermometer because the problem is likely right there.  The parkway  runs close  by with lots of trees so nit heavily industrialized in any manner 8.5” more like it .  How much do you think they got and how do think they  do with temps  and snow? 
it also appears the 6.9 they reported is snow only when looking at the color coding accumulation maps you provided?

 

I think they got about 7" like what was reported.  I got 8.5" and they had less precipitation than I did, which was particularly important in the snow period before the sleet.

12 hours ago, WEATHER53 said:

So the bottom panel snow only?  Nothing additional including  sleet? 
some stations have two different colored values, is that snow first and sleet and snow second 

The colors don't mean anything other than more or less snow/sleet.

[wxdude64]

12 hours ago, Roger Smith said:

DCA reported 1.99" liquid and 6.9" snow. If I'm generous and say .09" of that was freezing drizzle (probably an overestimate) then their snow report equals real snow plus sleet at some possible-to-calculate ratio after an assumption is made on the snowfall to liquid conversion. I will assume 10:1 in my calculation that follows.

So let's say 5" real snow, then we have

5.0 + 1.40*(ratio/10) = 6.9

That reduces to 1.40*(ratio/10) = 1.9

and makes ratio/10 = .21, in other words a 2.1 :  1.0  ratio. Sleet ratios are often quoted at 3:1. 

For 3:1 to be correct, then snow at 10:1 is 2.7" .. that is clearly a low estimate based on regional reports.

So either this was very watery sleet or very underestimated sleet. I would guess what really happened is that 3" of sleet pounded 6" of snow down to 4 inches and sat on top giving 7 inches.  

Yep, that is what happens 95% of the time. Sleet doesn't 'add' to OTG for a good while, it relentlessly beats whatever newly fallen snow to a pulp, reducing it by up to half depending on how fluffy (dry) or hard (wet) it was prior to the flip, and how hard/fast/heavy the sleet is falling. Once it reaches a compacted consistency, THEN sleet starts to add to the OTG totals. 

[mattie g]

2 hours ago, eyewall said:

Thank you and yep about to go to the dealer for when they open.

Not sure where you were when this happened, but someone on Reddit posted that they got the details of a car on 495 that hadn't been cleaned and ice flew off the roof and smashed another car's windshield.

[eyewall]

3 minutes ago, mattie g said:

Not sure where you were when this happened, but someone on Reddit posted that they got the details of a car on 495 that hadn't been cleaned and ice flew off the roof and smashed another car's windshield.

This was on I-95 so that was another incident for sure.

[H2O]

People that don't clear their ENTIRE car/truck/SUV are just lazy assholes.  Clean the fucking roof.  

[eyewall]

Just now, H2O said:

People that don't clear their ENTIRE car/truck/SUV are just lazy assholes.  Clean the fucking roof.  

I was told at the shop there is no law in VA to clear your car but yeah everyone should do it anyway.

[H2O]

Just now, eyewall said:

I was told at the shop there is no law in VA to clear your car but yeah everyone should do it anyway.

Windshields only.  But it's common decency to keep stuff like this from happening.  Sadly we all know how badly people care about others these days.

[Scarlet Pimpernel]

8 minutes ago, H2O said:

People that don't clear their ENTIRE car/truck/SUV are just lazy assholes.  Clean the fucking roof.  

Yeah I've run into that a couple of times, where the car in front of you still has a big layer of snow on the roof.  It leaves you in a localized mini-blizzard on the highway because the snow on their car blows backward onto you.  Real pain.

[nw baltimore wx]

17 minutes ago, eyewall said:

I was told at the shop there is no law in VA to clear your car but yeah everyone should do it anyway.

That’s ridiculous, but we shouldn’t need laws to do things like return your shopping cart and clean your car of dangerous debris.