January 6-7 Storm Discussion: we’re due?

[SnowenOutThere]

46 minutes ago, MN Transplant said:

Snow maps are going to struggle on the boundary.  Soundings and QPF are the way to go.  I’m modestly happy with this run sitting on the western DC Beltway.

Do you (or anyone else who knows) mind explaining how someone would be able to read the soundings to determine if it looks more white than wet, or the basics at least?  

[mappy]

7 minutes ago, SnowenOutThere said:

Do you (or anyone else who knows) mind explaining how someone would be able to read the soundings to determine if it looks more white than wet, or the basics at least?  

This might help!

https://blog.weather.us/guidelines-for-determining-winter-precip-types/

[WxUSAF]

My snowboard is at 378.4251969 feet per the LiDAR map. 

[Wxtrix]

11 minutes ago, SnowenOutThere said:

Do you (or anyone else who knows) mind explaining how someone would be able to read the soundings to determine if it looks more white than wet, or the basics at least?  

https://thecloudonline.net/blog/basic-skew-t-analysis-snow-or-no-snow/

 

there are dozens of sites out there, depending on how in-depth you want to go.

[psuhoffman]

1 hour ago, Kmlwx said:

For those of you that want to nailbite even more about elevation - this is the Maryland LiDAR viewer

https://geodata.md.gov/topoviewer/

Cool tool if nothing else - REALLY high-res data there. I think @mappy might have been the one to post it a long while ago. For map geeks, can get lost for hours in just scrolling around. 

That is awesome.  This is a pretty good took that has the whole country if you want to waste a lot of time.  

https://en-us.topographic-map.com/map-hqf3/Baltimore/?center=39.43478%2C-77.33712&zoom=9

[Fozz]

10 minutes ago, SnowenOutThere said:

Do you (or anyone else who knows) mind explaining how someone would be able to read the soundings to determine if it looks more white than wet, or the basics at least?  

The sounding just has to be entirely left of the 0C line to be snow.

[MN Transplant]

1 minute ago, WxUSAF said:

My snowboard is at 378.4251969 feet per the LiDAR map. 

Does that account for a close mow?

It is wild that this turned into a Saturday only event.

[WxUSAF]

1 minute ago, MN Transplant said:

Does that account for a close mow?

It is wild that this turned into a Saturday only event.

Yeah it really sped up. Even if some of the bigger totals that have been shown came to pass, not good timing for snow day hopefuls on Monday. 

[87storms]

Do you (or anyone else who knows) mind explaining how someone would be able to read the soundings to determine if it looks more white than wet, or the basics at least?  

Just keep in mind that each isotherm line has a positive slope because air generally cools with height. It’s a little counter intuitive at first. You also don’t want the parcel at the mid level heights to poke through the 0C line (ie, where melting occurs) for too long.

[psuhoffman]

 

50 minutes ago, H2O said:

If you are 300'+ and NW of 95 you will do ok.  This storm screams 12/5/2009 and for those who remember that one it was a brutal, just brutal gradient from east to west.  

For my location just S of DC barely sniffing 200', for the last 5-10 years any storm that has temp issues like this one has erred too cold and its stayed warmer than modeled.  UHI, microclimate, whatever.  Just won't bode well for storms like this.  

Will be lucky to get 1" unless there is a shift in storm track to the SE.  

There was a SHARP cutoff with a storm Dec 5 2003.  There was a WAA wave that came out first and thumped NW of 95, the costal developed a day later and mostly missed us and hit New England.  But the WAA lead wave had some local similarities to this.  I remember I got 7" in western Fairfax county and inside the beltway was pretty much all rain.  

[SomeguyfromTakomaPark]

53 minutes ago, H2O said:

If you are 300'+ and NW of 95 you will do ok.  This storm screams 12/5/2009 and for those who remember that one it was a brutal, just brutal gradient from east to west.  

For my location just S of DC barely sniffing 200', for the last 5-10 years any storm that has temp issues like this one has erred too cold and its stayed warmer than modeled.  UHI, microclimate, whatever.  Just won't bode well for storms like this.  

Will be lucky to get 1" unless there is a shift in storm track to the SE.  

320 feet in Takoma Park but I don't think it will help on this one unless as you noted we get a more southeast track.  Anything marginal in the last 5+ years has been rain for us if I am remembering correctly.

[HighStakes]

3 minutes ago, psuhoffman said:

 

There was a SHARP cutoff with a storm Dec 5 2003.  There was a WAA wave that came out first and thumped NW of 95, the costal developed a day later and mostly missed us and hit New England.  But the WAA lead wave had some local similarities to this.  I remember I got 7" in western Fairfax county and inside the beltway was pretty much all rain.  

That was a really nice storm for the suburbs especially for so early in the season. I got a storm total of 12 in Reisterstown. 7 with the initial wave and about 5 from the coastal. I'm pretty sure areas just west of the beltway from Randallstown over to Ellicott City did the best with the first round with some 8-10 inch amounts. 

[aldie 22]

7 minutes ago, psuhoffman said:

 

There was a SHARP cutoff with a storm Dec 5 2003.  There was a WAA wave that came out first and thumped NW of 95, the costal developed a day later and mostly missed us and hit New England.  But the WAA lead wave had some local similarities to this.  I remember I got 7" in western Fairfax county and inside the beltway was pretty much all rain.  

I was living in Woodbridge at the time and recall seeing on the news that Leesburg was getting hammered with snow while it was pouring rain at my house. On that day Leesburg 04 was born

[wtkidz]

All should be hoping for a bit more southern and eastern track.   To my uneducated eye , at the rate it is moving north and west  It  may only be the western side and pioints west  of the blue ridge having snow. Just sayin…

[psuhoffman]

The models are not "trending" or bouncing around so much as the operationals are simply randomly popping out solutions that fall within the still existing camps if you examine their ensembles.   One solution has now been completely eliminated and that was the phased amplified system with a primary into the Ohio valley.  That idea is pretty much dead.  But within the ensembles there are still 3 camps left.  We want the middle ground.  But it's well within probabilities for 2 or 3 operational models to pull a solution from the same camp (like last night) but its just random chance.  The 3 camps still left

A. A little too much amplitude and lingering primary and the main snow shield goes just NW of us.  This is a messy one with not a lot of snow for anyone because the primary is weak, the phased amplified solution is gone.  But this would take a lighter snow event up into PA. 

B.  The in between option, GFS and GGEM op solutions from 0z and 12z.  No primary at all, coastal is just amplified enough to produce a thump snow targeting just NW of the fall line 

C. A weak sheared out mess with no significant snow anywhere.  This solution might target DC south with the best qpf but it won't work with the marginal temps.  

The 6z EPS took a move towards Camp B but there was still a mix of all 3.  

GEFS is still a mix of all 3.  

GEPS is all option A and B.  

I don't think the models have trended yet, they seem to still just be pulling random options from within these established goalposts run to run.  

[Fozz]

4 minutes ago, HighStakes said:

That was a really nice storm for the suburbs especially for so early in the season. I got a storm total of 12 in Reisterstown. 7 with the initial wave and about 5 from the coastal. I'm pretty sure areas just west of the beltway from Randallstown over to Ellicott City did the best with the first round with some 8-10 inch amounts. 

I wish I measured during that storm. It was probably similar in my location, I remember it really coming down hard in the early morning hours with a lot more snow than most were expecting. Then it changed to rain for some time. Then the overnight coastal.

Probably the biggest December storm I’ve seen until 2009.

[osfan24]

57 minutes ago, hstorm said:

I will take this as gospel with our 340' elevation.  More seriously and on topic, agree that past experience suggests a significant NW/SE FFX county gradient in NoVA.

Ha, I saw that post and decided I would check my elevation since I only moved here a few years ago. Elevation map claims I am at 457 feet, which I find hard to believe. Anyway, I think this is the first storm where I could really potentially see how much my location helps vs. being along 95. I'm right off of Route 40 a few miles before it dead ends into I-70.

[WxUSAF]

I’ve seen the option C in the ensemble mix (I think based on snow maps posted), but not sure any op run has pulled that out (yet). Ops seem to be switching between A and B or some blend between them. Let hope Euro can pull a B here…

[WinterWxLuvr]

5 minutes ago, wtkidz said:

All should be hoping for a bit more southern and eastern track.   To my uneducated eye , at the rate it is moving north and west  It  may only be the western side and pioints west  of the blue ridge having snow. Just sayin…

Some of us live there and don’t want anything to do with further south and east. Just sayin ..

[HighStakes]

2 minutes ago, Fozz said:

I wish I measured during that storm. It was probably similar in my location, I remember it really coming down hard in the early morning hours with a lot more snow than most were expecting. Then it changed to rain for some time. Then the overnight coastal.

Probably the biggest December storm I’ve seen until 2009.

I went to my friends birthday party in Cockeysville/Hunt Valley the night after the storm and the snow depth was about the same as in Reisterstown.

[WinterWxLuvr]

1 minute ago, WxUSAF said:

I’ve seen the option C in the ensemble mix (I think based on snow maps posted), but not sure any op run has pulled brag out (yet). Ops seem to be switching between A and B or some blend between them. Let hope Euro can pull a B here…

Another option is a bomb over the outer banks that can create a scenario of heavy snow that can overcome marginal temps. I’m hanging my hat on that one lol

[psuhoffman]

3 minutes ago, WxUSAF said:

I’ve seen the option C in the ensemble mix (I think based on snow maps posted), but not sure any op run has pulled that out (yet). Ops seem to be switching between A and B or some blend between them. Let hope Euro can pull a B here…

NAM had that solution.  Ya I know the NAM lol.  I think it's likely going to be something from A or B, or maybe a compromise between the two.  But C is lurking if there is any additional de amplification trend in the STJ wave.  

[clskinsfan]

2 minutes ago, WinterWxLuvr said:

Another option is a bomb over the outer banks that can create a scenario of heavy snow that can overcome marginal temps. I’m hanging my hat on that one lol

The CMC is our best option. Sub 1000 at the mouth of the bay is primo for us.

[WxUSAF]

4 minutes ago, clskinsfan said:

The CMC is our best option. Sub 1000 at the mouth of the bay is primo for us.

That’s basically what the Ukie was also

[psuhoffman]

Euro has slightly better confluence and High location than GFS at the same time at 63 hours...but the SW is weaker and further north.  Not sure which is more important at this point.  

[psuhoffman]

That trend continues at 72, high is MUCH better located on the Euro than the GFS, however that might be offset by more ridging in front of the wave.  

[NorthArlington101]

Just now, psuhoffman said:

That trend continues at 72, high is MUCH better located on the Euro than the GFS, however that might be offset by more ridging in front of the wave.  

looks very similar from a RA/SN line perspective by hr78. Gotta be west of the beltway

[NorthArlington101]

1 minute ago, NorthArlington101 said:

looks very similar from a RA/SN line perspective by hr78. Gotta be west of the beltway

actually it's worse - you are raining by 4:00pm

it's kind of a disaster

[Terpeast]

Just now, NorthArlington101 said:

actually it's worse - you are raining by 4:00pm

When does it have precip starting? 

I’m still on 6z on TT 

[DDweatherman]

1 minute ago, NorthArlington101 said:

actually it's worse - you are raining by 4:00pm

it's kind of a disaster

It’s only ever right when it’s by itself when it shows a bad solution. It doesn’t agree with the consensus of other models, but it isn’t what we wanted to see…