The PSU (Cherry Pie) March 13-15 possible snowstorm

Winter storm watch has been issued for DC metro. 5+ inches of wet snow expected.We will get a storm. The thing is we're walking a tightrope in regards to precip and temperatures. Too far west of a storm and we mix. Too far east or if the low pressure centers fails to consolidate fast enough, precip totals could be lower. There are still plenty of details to hash out.

In case you're wondering where the bar stands for snow:
Exceptional: Top March DC snow event (12.0" to tie 1891)

Excellent: Top 5 March snow event (9.8"+)
Good: Top 10 March snow event (7.5"+)

Also we're at like 2" for the entire season.... Won't take much to double that.

If the NWS issues warnings later, then expect Tuesday off. Maybe a early release on Monday too. We'll see.

Timing:
 Rain/snow in the late Monday afternoon into early evening changing over to snow. Temps in the low 40s, upper 30s. Heaviest snow late Monday night into early Tuesday morning. Temps in the low 30s to upper 20s.  There is some potential for mixing with sleet and rain depending on the exact low track. Light snow diminishes during the day with some steadier snow possible Tuesday night as the upper level low passes

Snowfall:
There is a decent consensus among global models for at least 1" of liquid equivalent precip. If all snow, @10:1 ratios, that would give us 10". Since it's March and March is warm, the snow will likely be wet and pasty, great for snowmen, but also low ratio and naso great for the trees. If heavy wet snow does materialize, power outages could be an issue (look at Jan 26, 2011). As usual with the elevation/temperature gradient of Montgomery County, snow amounts will be significantly higher in the upper part of the county than the lower part, as much as 6" different (rather arbitrary but you get the point).

Another thing is the instensity of the precip. As the storm bombs off the coast, we get slammed by a slug of tropical moisture. Much of our snow falls overnight, in the way early morning hours. This is the highest confidence part of the storm. As much as 10" could fall then, and then as the storm winds up and pulls away, moisture throw along the backside could bring some more snow. This part is less certain because there will be two initial lows, one well NW and one a coastal. Depending on how long it takes for the coastal to absorb the NW low, the NW low could disrupt the circulation of the coastal and therefore prematurely end the snow.