Terpeast

Sorry if posted before. Afternoon AFD from LWX. Bolded is my own emphasis. .LONG TERM /SUNDAY THROUGH THURSDAY/... Sunday will start off dry as surface high pressure shifts offshore to our southeast. High temperatures will be in the 30s for most with those along the highest elevations and in the Alleghenies staying in the 20s. By Sunday afternoon, snowfall moves into the southwestern portions of the forecast area as a low pressure system tracks from the Mississippi River Valley towards the forecast area. Snowfall spreads throughout the forecast area Sunday afternoon and continues overnight. Cold temperatures will likely lead to precipitation type being primarily snow, though a warm nose aloft will likely lead to sleet/freezing rain mixing in overnight. Highest chances for sleet/freezing rain is across central Virginia and into the Allegheny Highlands. Ice accumulation forecast ranges from zero in the northwestern portions of the area to up to a quarter inch near Charlottesville. Currently have ice staying south of the I-66 corridor, though there remains uncertainty in the forecast given the event being several days out. For snowfall, highest forecast totals remain along and west of the Alleghenies where totals of 8 to 10 inches are forecast. Further east, snowfall accumulation is forecast across the entire area with totals ranging from 2 inches in the southernmost portions of the area to nearing 8 inches across central Maryland/eastern panhandle of WV and the western portions of Virginia. Metro areas will likely see 4 to 6 inches of snow with higher totals possible. The exact snow total forecast is subject to change due to the winter event being 4 days away and model variability with mixed precipitation. 12Z guidance continues to show a good bit of discrepancy with the ECMWF having highest totals farther south and the NAM having highest totals along the MD/PA border. We will continue to monitor the forecast as the event gets closer, but for now prepare for a moderate winter storm bringing mixed wintry precipitation to the area Sunday into Monday.

Suddenly fatties

Snowing better now. 37

Tough forecast for the Wakefield office. Very high bust potential... even moreso than here or Mt Holly

Wet mangled flakes

Sprinkles. Temp dropped from 42 to 39

Flurries in ashburn, 41

Gotcha, thanks. Good to know it wasn't intended for scrutiny

They seem to think that CAD holds strong and keeps mixed precip to the south of DCA

if the temp straddles the 0C line on the sounding, but doesn't nose to the right of it, it's snow. But if we see an obvious nose to the right of 0C for about 500+ feet, it's sleet or freezing rain depending on how thick the surface cold layer is.

That southern gradient of snow totals suggests the mix line bisecting DC at its northernmost extent, but staying south for the most part.

Sounds like a thump to dry slot / light precip and then back to powder. Although I'd prefer an all snow event through and through, that scenario is more than acceptable.

That part is going to be very fickle and likely won't be resolved until right up to game time.

This is close, but still snow.

Open wave at 78 instead of closed vort same time previous run

Good to see you here. I hope the south shift is correct and you get snow, too!

Stronger vort + stronger confluence will get that done for us

100% this. Getting a 150 mile swath of snowfall correct from 3-4 days out is the equivalent of netting a basketball from half court.

Total hunch, i think it stops today 12z or 18z then once the system gets going east of the rockies, they tick back north

Low of 24.8, my weather station usually in line with others around me, if not 0.5 warmer. But it radiates really well at night or even early morning with no wind.

Yeah, I’ve been watching that feature since last night. Lots of moving pieces in that gyre and one might interact with the s/w for better or worse. For now (and this could change) it pushes the wave down and the models are picking up on it. My biggest hope is that it prevents an icy mess along i-66/i-95

We have some breathing room. Again. For how long? Who knows.

Yep, and even if the M/D line or i-70 north don’t get the qpf max, their ratios should make up for it. Mitchnick is still good, probably.

Feel better soon!

It is a delicate balance that involves luck and timing. We have that northerly cyclonic flow from Canada, but it really is a thread the needle situation.