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The initial band looks to target center of AGC and south,

36 so far most cloudy a little bit of sun

Might as well throw some accums out since this event is pretty close to starting in western PA. This is going to be a pretty big event in the western mountains. The western ridgelines of the Laurels may near double digits just from the event itself with the upslope flow and cold column (high ratios). Still going to be that corridor of reduced accums in the Ridge and Valley, although this has looked somewhat better as this has gotten into the realm of the near term guidance. I think most everyone will see at least an inch. That narrow corridor between the Allegheny front and I-99 may manage low end advisory amounts. Along with the somewhat better carry-over where the downsloping occurs, near term has also looked better in the Sus Valley for the precip shield reorganizing as the system gets to the coast and the column/surface cools further. Ratios won’t be as high as the Laurels, but it’ll still be pretty decent (perhaps as good as 14-15:1). The best precip coincides roughly with the -8ºC 850mb isotherm as it tracks across PA. It wouldn’t take much more QPF to make for a low end warning event in the Sus Valley. Western PA Pittsburgh metro and surrounding: 4-6” Washington: 5-7” Butler/Indiana: 3-5” Seven Springs: 6-10” (+ additional with LES and upslope after) Central PA Johnstown/Somerset: 4-7” (+ additional with LES and upslope after) Clearfield: 2-4” Altoona: 2-3” Bedford/State College: 1-2” Huntingdon/Lewistown/Williamsport: An inch or so Sus Valley Selinsgrove: 1-2” Gettysburg: 2-3” Harrisburg area/Tamaqua: 2-4” York/Lancaster: 2-4” (possibility of some 5”+ amounts)

What’s the status of the Christmas 70 degree torch?

Why does CWG always update before euro data?

Looks like this winter will be significantly different from the last few. As we all know 3-4”+ in a nina december stacks the odds heavily to a 30”+ winter for our area.

Here's the criteria for a Winter Storm Warning in the LWX CFA: A Winter Storm Warning is issued when a significant combination of hazardous winter weather is occurring or imminent. Significant and hazardous winter weather is defined as a combination of: 1) 5 inches or more of snow/sleet within a 12-hour period or 7 inches or more of snow/sleet within a 24-hour period AND/OR 2) Enough ice accumulation to cause damage to trees or powerlines. AND/OR 3) a life threatening or damaging combination of snow and/or ice accumulation with wind. The snow/sleet criteria for a Winter Storm Warning for the five westernmost counties (Allegany, Mineral, Grant, Pendleton, and Highland) is higher (6 inches or more within a 12-hour period; 8 inches or more within a 24-hour period).

It's been that way.

Yeah Euro looks like 3 to 4 for a lot of the area. This looks like a 2 to 4 inch snowfall with some areas getting as much as 5. Nice to get this type of event in the first half of December. Hopefully a good sign for the winter.

CWG bumped up a little

Yeah, I was saying something similar earlier (without a sounding though) — if I was going to be home in Alexandria for this, I still wouldn’t be sweating temps. There’s cold air above very close by and DP as precip starts is probably ~31.

The hrrr absolutely hates Loudoun on every run.

So the slight drop off isn't so much temperatures as it is where the precip sets up?

39F here, radio met here saying no more than a couple of inches OTG here by AM.

sure, why not.

Latest HRRR at H18 (snow still falling) - actually seems in line with Euro.

Euro Kuchie stolen from the MA. Another small bump up in totals. what’s warning criteria down here in York and Lanco? 4-6?

South of 195 is even worse. BOX has the new Pit as rain until after midnight.

Here's the 3k NAM sounding right as precip is about to start in DC. Above freezing part of the column is *extremely* shallow. Like 975mb or lower? And even that part of the column has a wet bulb of 32-33. At worst, that's probably like a few minutes of sprinkles and as soon as there are any rates at all, it's snow.

It gets drier as other guidance is juicing up. Toss.

Good sign. We might go to town for a few hours if we can get some good moisture transport north and banding. Thank goodness this isn't another system with lame cold air and we have fresh arctic air plunging in when the winds turn north.

Euro wetter for nyc and LI

In the interest of showing objectivity, I expect the 12Z Euro, which is about to be released, to not be as cold as the 0Z that I posted 3 temp anom maps from. But the overall trends toward not as warm, more CAD, and instability of models within just a week seems real to me and tells me not to bet the farm at least yet on a mainly mild 12/18-31 mid-Atlantic south like has been suggested by ens. means. We’ll see

It had been skunking us for days but is now essentially identical to the Euro