high risk

Yes, that is the current target.

If he did, he is wrong.

see Eskimo Joe's latest post. It is indeed fine in the southeast part of the county, but it's a massive mess in the other half. Lots of stuff on the school system FB page of cars and busses having to navigate around downed trees and overall icy conditions.

the county school system made an awful call to only have 2 hour delay today. It's fine here in the southeast part of the county, but it's a massive mess in the northwest half. But they got skewered in the press for closing yesterday and swung the pendulum too far back the other way today

If the GFS is right about the front returning north on Thursday, we have a legit shot to hit 70.

can't disagree. the hi-res models just aren't meant for short-range details of winter snow bands; they're meant for deep convection. the radar reflectivity assimilation doesn't work properly with low dbz stuff.

very meh right now but should be improving shortly.

HRRR suggests a midday break and then perhaps another very light round of snow this afternoon

If I'm reading the AFD correctly, LWX is going to issue a winter weather advisory for DC/Baltimore metro.

yes, but of the models that generate snow, most have it starting during the morning commute. That's the point.

this is going to make for another super challenging decision for schools, as if it does snow, it will fall during the morning rush. We're obviously talking about small amounts, but even a dusting would cause road issues with these temps.

can you please be more specific when identifying the 'WRF'? Since you're referring to TT, I assume you're talking about one of the three hires windows, labeled as WRF-ARW, WRF-ARW2, and WRF-NMM (which should be labeled NMMB, but that's another issue).

pretty much all guidance has the temperatures crash behind that arctic front

definitely some great signals on the hi-res guidance. The Hi-Res Windows (particularly the NMMB and ARW2) look awesome

they're basing that off of a single HRRR run, and while the simulated reflectivity field does look better, it's still showing 36-38 degrees during their "time of excitement".

followed by a rapid and dramatic temperature drop. would be crazy if the bigger commute issues end up occurring Wednesday afternoon instead of today.

That would literally break this board, but the plan to run the NAM in hourly rapid refresh mode was scrapped many months ago.

yes, but the HRRR warming occurs after the precip shuts off edit: and as expected, with that warm afternoon, the temperatures barely drop in time to give us a pity amount of wet snow at the end of the rain

really strange in that it looks like it's snowing pretty good according to the reflectivity, but there is no precip accumulated. Looking at the soundings, it's insanely dry in the low levels, so I guess it's virga, but it seems odd that it would snow decently for a few hours and never reach the ground. It's also surprising that the HRRR takes much of the area into the low 40s during the early afternoon.

this is the type of event in which resolution and explicit convection (as opposed to a convective scheme) will help a lot, so the NAM nest forecast may be legit. yes, but it's so narrow and fast-moving that I'm not thinking in terms of accumulations. It's more of a deal with potential quick reductions in visibility and then freezing of snow on the ground if enough falls to cover surfaces.

Love the line of snow squalls on the arctic front midday Wednesday on the 18z NAM nest. Forecast soundings show impressive low and mid-level lapse rates!

mid-March at the earliest. The final 30 day stability test has not yet been run.

agree totally with this. it's also complicated by the NAM and HRRR showing light precip for the *morning* rush hour too, especially north of DC. Depending on your model of choice, it could be snow, sleet, or freezing rain.

Even if this ends up as only an inch or so of snow, this is going to be a high-impact event for sure. With temps falling into the 20s quickly after the precip ends, that covering of snow will freeze quickly and lead to icy streets and sidewalks. I expect widespread school delays Wednesday morning, with cancellations also possible, especially if the 00z GFS is right with us not getting anywhere near freezing Wednesday. (Earlier runs and the 00z NAM have us getting to near 30 Wednesday just ahead of the push of the real arctic air.)

I'll go back to my earlier post and say that while it's still most likely that this will have no impact (either due to no precip or warm temps), ground temps are extremely cold, so light rain falling at 35 degrees tomorrow could cause some icy surfaces. We've see this happen before.