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

[Paleocene]

1 minute 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. 

Gonna use all of my 98 meters!

[Roger Ramjet]

56 minutes ago, aldie 22 said:

Curious what part of Western Loudoun are you in....is it for real Western Loudoun or Ji's version of Western Loudoun? If it's for real Western then i think your area is in a pretty good spot for this one especially Round Hill on West

I'm between the hills (Harpers Ferry Road) about 3 miles south of Harpers Ferry. I have a long access road and about 150' higher than the road surface at 725'. It may be a sweet spot for this storm. I've had a couple inches on the ground before and drove through Hillsborough on the way to work with nothing on the ground.

[87storms]

Seems a *bit* overdone for such a fast mover, but man...being right on this R/S line is leaving me with few to no fingernails already.

It’s dicey up here, too. I’m kinda surprised at the model snow output, all things considered…but I’ll take it.

[Buddy1987]

anyone still have access or know where to get it for ice accumulations. A lot of models I’m seeing are showing an icy setup down this way.

[mappy]

4 minutes ago, 87storms said:

It’s dicey up here, too. I’m kinda surprised at the model snow output, all things considered…but I’ll take it.

Elevation will only help so much, eventually the warmer column will win. Front end thump is where it's at before we all dread the mix line on CC lol

[MillvilleWx]

27 minutes ago, clskinsfan said:

Its a 3-5/4-8 type thumper. We havent had one of those for a while. I am looking forward to it. 

This is very much what I’m leaning right now. I’m still curious to see the PBL on soundings when we get to Nam Nest and hi-res range. That’ll help out tremendously in the snowfall forecast. 
 

Edit: This is more for NW of the fall line with the best chance north of I-70 and west of US15. I’m leaning 1-2” in the district with a small incremental increase the further NW you go. 

[IUsedToHateCold]

The models have been consistent that this is a fall line storm. There will be a brutal cutoff and if I had to guess it’s going to be just west of 95- where it always is. Perhaps those of us down in the lowlands have a shot, but I’m prepared for disappointment and if you live where I live you should be too 

[adelphi_sky]

21 minutes 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. 

I'm right at the base of the fall line in Adelphi. It could go either way for me. lol Thanks for sharing this tool. 

[87storms]

6 minutes ago, mappy said:

Elevation will only help so much, eventually the warmer column will win. Front end thump is where it's at before we all dread the mix line on CC lol

lol, I wonder how much sleet is really gonna be at play with this one.  Seems like mostly a rain or snow situation, but I could be wrong.

 

[DCAlexandria]

23 minutes 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. 

anyone have this tool for VA?

[NorthArlington101]

I take back what I said about the GEFS. Mean initially looked better, but checking out the median reveals an outlier or two is tossing things up. Overall - GEFS throws out a weaker system. Looking at the ens is nearing (if not hit) it's expiration date anyway, but the >1" probs aren't exactly thrilling 

[mappy]

3 minutes ago, DCAlexandria said:

anyone have this tool for VA?

not as nice as MDs

https://en-us.topographic-map.com/map-m4z4/Virginia/

[hstorm]

2 minutes ago, DCAlexandria said:

anyone have this tool for VA?

Don't know about VA generally, but here is the Fairfax County LiDAR site: https://www.fairfaxcounty.gov/maps/topographic-data

 

[caviman2201]

FWIW, the 12z GEFS surface low track is still ~75mi or so SE of the GFS op. 

Op seems to go from Norfolk to Cape May while GEFS goes Nags Head to 150mi E of Chincoteague

[mappy]

6 minutes ago, 87storms said:

lol, I wonder how much sleet is really gonna be at play with this one.  Seems like mostly a rain or snow situation, but I could be wrong.

 

You're right, but even rain/snow line shows up on CC

Checking GFS soundings for MBY, and I'm 31-32 the entire time. Going to be a mix of rain, snow, rain/snow even for me.

[WinterWxLuvr]

Think I’ll not put any eggs in the GEM basket. Waiting for the euro but there’s still room for this to be big IMO. All I look at is the 500 map at about Fri morning. That’s gonna tell the tale. There’s room for improvement there and the gfs did so ever so slightly 

[H2O]

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.  

[digrox]

10 minutes ago, hstorm said:

Don't know about VA generally, but here is the Fairfax County LiDAR site: https://www.fairfaxcounty.gov/maps/topographic-data

 

Here's nationwide LiDAR (VA included, obvs) from the USGS: https://apps.nationalmap.gov/3depdem/

[Newman]

Ukmet definitely cut back for max totals west of 95, QPF a bit less. General 6-10" swath. DC would be marginal

[Paleocene]

12 minutes ago, caviman2201 said:

FWIW, the 12z GEFS surface low track is still ~75mi or so SE of the GFS op. 

Op seems to go from Norfolk to Cape May while GEFS goes Nags Head to 150mi E of Chincoteague

[NorthArlington101]

1 minute ago, Newman said:

Ukmet definitely cut back for max totals west of 95, QPF a bit less. General 6-10" swath. DC would be marginal

850s are sooooo close, but surface temps are shot. That said, UKIE thermals are lol. Cville is placed into an isolated freezer with the 6" of snow it gets this run

[hstorm]

Just now, 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.  

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.

[Kevin Reilly]

9 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.  

Media Delaware County Southeastern PA is 310' how will we do?  I am thinking 2-4" / 3-5" before we flip.

[WxUSAF]

6 minutes ago, Newman said:

Ukmet definitely cut back for max totals west of 95, QPF a bit less. General 6-10" swath. DC would be marginal

Looks qualitatively consistent with gfs and GGEM with a solid thump and then mixing dependent on location. 

[Fozz]

12 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.  

That was the storm that turned my elevation into a meme. Nearly 6” IMBY while the other side of town at 250’ had 2.5” of slop. And I was very annoying about it.

I think it’s up in their air where that line will be this time. It could just as easily have a 2/3/2014 or Oct 2011 gradient.

[Duca892]

Thinking a general 3-5in for the Lehigh Valley areas in SEPA looks about right

[StormyClearweather]

12 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.  

NW of 95, but literally at 299 feet. Fortunately, I live about halfway down the hill, so it's a short walk to 300. 

[rjvanals]

11 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.  

In that storm I went from my parents house in Potomac where we had a plowable snow to Comet Ping Pong in NW where it wasn't much more than a cartopper. 2-17-18 was another one w a sharp gradient from downtown to western suburbs as well. 

[Kevin Reilly]

I think we see models consolidate and come to consensus by 12z Thursday, January 4th.

 

Thinking 1-3" DC to Baltimore ..... 2-4" PHL as someone said over 350 feet 3-6" beyond the fall line north and west 6-8" 

 

Typical 95 north and west deal... south and east of 95 good luck 1" or less. As I see it right now.

[Terpeast]

4 minutes ago, StormyClearweather said:

NW of 95, but literally at 299 feet. Fortunately, I live about halfway down the hill, so it's a short walk to 300. 

I'm at 325 ft and the creek below me is probably 300' on the dot