Disc

Still a lot of cloud cover and drizzle across much of Virginia leading to a lot of uncertainty. If we can start to break out of the clouds, I think this has a decently high ceiling considering the parameter space in place.

CAMs are rather impressive with discrete cells forming in NC around 21z and then moving into Virginia and congealing more into a broken line as they progress into Central and Northern VA by 00z - 03z. Some impressive helicity tracks are noted moving into Southern Virginia, but wane a bit as they move north of I64, where I'd say this becomes more of just a wind threat. 

The new RRFS has been the most robust with this advertising multiple discrete cells, but the HRRR and NSSL/WRF models have a similar idea. I believe the WoFS will be run starting at 17z which has proven to be quiet skillful in the near term.

Light snow for about an hour or so.

Large debris fallout in correlation coefficient. A significant tornado likely occurred. Hearing reports of people trapped in Nash County.

Lots of golf ball and even a tennis ball size hail from the storms in C VA today.

All sleet in Blacksburg, VA.

edit: and now just rain.

1 hour ago, Buddy1987 said:

That’s a Floyd VA to Blacksburg and NRV mauling. 
 

Also you know something’s up when @Discis lurking.. 

Here and watching. Our best chance at snow all winter. ULLs can do some crazy stuff, so this will be a wild ride the next few days.

6 minutes ago, Chris78 said:

What's the 18z based off of if none of the 18z models have ran yet?

Think of the NBM as a cycle or two behind the deterministic guidance. The 18z NBM has the 12z GFS/GEFS, but still has the 00z ECMWF/EPS and some 06z guidance. Full ECWMF 12z guidance is not within the NBM until its 21z run.

Damage in Bedford Co

I like where this was going..

23 minutes ago, Buddy1987 said:

The ULL really concerns me. If we can get it underneath us somehow (which it's close) that will help for sure. But the problem is it pushes all the WAA up over us and would most likely flood the mid levels with too much warmth. So far the models are not wanting anything to do with mixing out here. 700 looked good for the snow growth dendrite area and 850s were fine. Hell you can correct me if im wrong but im not sure I saw it get above -3/-4 celsius and then as the ULL swings through it plummets down to -8/-10/-11

Side note was just looking at GFS. Weird to see thermals colder than Canadian. Usually its the opposite. Canadian one of the most amped. 

Globals are keeping it just under the 0c isotherm, but I still don't think they're picking up on the warm layer. I'd be glad to eat my words later, but this one just screams mixing all the way into western VA.

We do get a good ULL pass so that may help at the end. 2014's storm was further east though. This one is way inland and we had mixing issues up to the Blue Ridge in 2014 with a storm that was further east. Perhaps trends will improve tomorrow, there's still a little time left.

I am just not feeling this for southern/SW VA. With such an inland track and secondary low still wanting to go up the Apps, we will mix sooner than later. I've seen it numerous times. This is why I was hesitant earlier to say 12" up here is a lock and the trends this evening have me even less confident. 

18z ECMWF was similar to the 12z run. The low transfer to the coast took slightly longer though.

30 minutes ago, Buddy1987 said:

@Disc what kind of timeframe are you seeing for snow to start. Late Sunday morning? 

I'd say between 7am-10am.

4 minutes ago, Buddy1987 said:

Man apparently my ripe age of 34 is starting to affect my memory. I do remember 2018 but if I remember we got like 9” out here in Salem. Well hopefully you live close by because from my house out that way the stretch on 81 would be insane to try and make the journey going up into the mountains 

I don't live too far from the office, but will be an interesting ride. If I can make it out of the neighborhood to 460 I think I should be ok.

If I had to commute from Roanoke I don't think I'd make it up Christiansburg Mountain.

27 minutes ago, Buddy1987 said:

I find it funny on the surface map verbatim me and you are a tiny little bubble still surrounded in all snow sounding. Probably has been a solid 10 years since we’ve had this opportunity (believe it was winter of 2011 when we had that big big snowstorm). Are you working in Blacksburg this weekend or do you get to enjoy it? I’m looking to get the party officially started with a WSW with tomorrow mornings products 

Last good one (12"+) was Dec 2018 so it's been a little while. Before that one I'd have to go back to Feb 2014. 

I am going into work late Sunday night and will be working all night. I am rooting for an earlier starting storm for 2 reasons.. 1) This would mean less of a mixing concern here and (2 It would be over with by the time I have to go to work. 

The trends this morning have favored this so let's hope it continues.

2 minutes ago, Jonathan said:

You think we have a chance to hold on to sleet rather than freezing rain down towards Franklin and Patrick counties?

Sleet is most likely. The depth of the CAD is very large. This is not the typical shallow CAD scenario.

6 minutes ago, Buddy1987 said:

@BornAgain13 man that snow band verbatim would be absolutely insane over southern VA

We're sitting good up here. I'm not ready to say 12" is a lock, but the trends this morning have been good.

1 hour ago, Buddy1987 said:

@Disc what are your thoughts this far out regarding WAA overriding the cold dome over us? Any in house model data showing more of a pronounced warm nose or do we snow heavy and hard out here?

Pretty certain we'll be mixing at some point. Hard not to when there's a sfc low riding up I-95.

LP transfers to the GA coast early Sunday afternoon. 1001mb. Mixing in NC. Mtns do well.

Heavy snow breaking out across NC at 15z Sun.

Just now, Ji said:

My guess Is ukmet is has low either over erie pa or Jacksonville fl

Ukmet is 18" at DC on Kuchera clown map. 

1 minute ago, Buddy1987 said:

Anyone have any idea how accurate RGEM is toward the end of its runs? Looks to be a little east of the GFS position comparing. Someone with a red tag or with much more knowledge than me can maybe explain known tendencies of GFS, i.e. driving LP's into cold domes or scouring out low level cold air. 

I really don't use it outside of 48 hours. It's fun to look beyond, but take it with a grain of salt.

I will say this: I have never made a forecast using the ICON model. Entertainment at best.

Just now, Blue_Ridge_Escarpment said:

2 feet at GSO

Yep, this is a money run for areas between US460 and I40.