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

[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

[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