Cobalt

Might be weenie folklore but it's only fitting that this window is showing back up as our current system is exiting stage right. GEFS is still offshore but beefed up, a lot of monster lows within range.

2015 all over again.

Still at 13 degrees with heavy sleet in Harrisonburg. Nuts.

Looks like you're getting quite the prolific storm up there. Would love to hear your observations, enjoy it!

Eyeballing from my window but maybe 2-3 inches? Grass is completely covered, and it already looks like the sleet has tried its best to cover up some of the pathway footprints. 12+ hours of this stuff might match or exceed our snow total.

Those yellows to the southwest of y’all look like they want to break free from the CC sleet line. Hope you guys get crushed with that stuff. Solid snow back home in NoVa, meanwhile we’re constructing the next glacier here.

It’s a bizarro world, down to 9 degrees with moderate sleet here.

IIRC most of the mesos had me flipping 1-2 hours before DC did. Perhaps the sleet line is going to halt after this quick advance but TBD. This does open up a shot at a ridiculous sleet storm, as the HRRR suggests 1.2" QPF is to fall from this point onwards. If a majority of that is sleet.. woof.

Harrisonburg

Suspicions were right, hearing sleet mix in now.

SN+ at 10 degrees, probably a once-in-a-decade type obs combination around here. Huge huge flakes.

Absolutely gargantuan snowflakes right now. Was gonna take a nap until 5am but this is compelling me, especially with that sleet line to the Southeast. A flip to sleet would be hours early, and I'm hoping this increase in flake size isn't signaling that outcome. For now, SN/SN+.

Euro clips the SC/NC coast, 989mb storm offshore. It's not particularly close to us but it isn't 500+ miles OTS like the 12z. EPS is about 0.15" QPF for DC in that window. Not much but a step in the right direction.

The type of observation we're gonna look back on years from now. So curious as to what the coldest ever sleet observation is, that's gotta be close. 11F with -SN/SN here.

11F, -SN. Perfect conditions for the dorm fire alarm to have gone off and send everybody outside..

11F with -SN. Larger flakes starting to pop in with the pixie dust. Seems to be go time! Might be the last time I see bare ground until the second week of February, kind of incredible.

The rates right before the flip would be very nice. 0.1-0.2" QPF in an hour, probably some huge silver dollar style flakes before the changeover

16 degrees in Harrisonburg

GEFS is pretty enthused at this range

Before the upcoming cold snap.. DCA currently sits at 37.7F for the winter, 21st coldest winter since 1970 (arbitrary cutoff), and 0.7F below the 1981-2010 average. That figure is most certainly going to drop, but I'm not sure it can be overstated in how potentially prolific the upcoming cold snap will be. 12z GFS' raw output for temps at DCA has the 24th-31st averaging 17.6F, which would be the coldest on record for that time period. For a laugh we can take the Euro's output from 2 days ago (the most recently accessible chart on the weathermodels site) to find that it has DCA averaging 12.2F for that timeframe. The Euro has an obvious cold bias with snow cover and IIRC has backed off a bit from that ridiculous number, but all of this illustrates how potent the upcoming cold will be. The "tamer" solution still challenges the coldest last week of January on record.

Digital snow hall of fame potential if it kept going past 240. Kuchera shows 32" falling in 6 hours lol

Incredible similarities between the surface and h500 depictions on both the GFS and Canadian at 192 hours.

Seeing the SREF and NAM not super insanely amped (just regular amped) with the WAA is a bit encouraging. In similar borderline setups they've loved driving that initial precip well north of us at range, typically comically so. I guess that implies that the airmass and associated confluence are legit enough to shunt out those solutions from the usual suspects.

Many of the analog events had surprise winners from the front end thump. Folks brought up Feb 21, 2015 as such an instance. Feb 16, 2016 is another good one, that had brutal cold leading in.

Looking back at the Feb 21, 2015 storm someone mentioned in the other thread.. woof, quite the boom. Let's hope a similar thump is in store this time around, but area-wide. Accompanying article for anyone interested https://www.washingtonpost.com/news/capital-weather-gang/wp/2015/02/22/the-meteorology-behind-saturdays-multiple-choice-winter-storm/