yoda

From updated LWX AFD as of 720 PM 12z and 18z guidance has unanimously shifted northward. Mean QPF from model output has risen to nearly an inch at the southern most reaches of our CWA (southern Nelson County), and just under a half inch near CHO. The northern edge of accumulating snow remains a challenge, but there is a non- zero/increasing chance for flurries or a light coating of snow to near I-66/US-50, in line with the northern edge of a baroclinic leaf developing upstream on satellite (marking the northern edge of stronger synoptic upward motion). As such, have upgraded to a Winter Storm Warning for Nelson County and the central Blue Ridge Mountains, with a Winter Weather Advisory for Albemarle and Augusta Counties. Winter Weather Advisories may need to be extended farther north in area into the Virginia Piedmont and portions of the Shenandoah Valley of Virginia, and Winter Storm Warnings may need to be extended north in area into portions of the central Shenandoah Valley and perhaps as far north as the Virginia Piedmont. Will re-assess headline decisions with the 00z guidance later tonight. If the northward trend continues (and it has for the last few model runs), then snow amounts will need to be increased and headlines will have to extend farther north. The most likely forecast was tweaked up slightly from the 12z forecast, which leaned about 2/3rds on a straight blend of 12z guidance and 1/3 previous forecast for continuity`s sake, offering respect to the strong confluence zone to the north. However, some outlier ensemble members continue to show even higher significant snowfall amounts (see Winter Weather Page at www.weather.gov/lwx/winter for latest range of possibility graphics). Since this is a dynamic system with a lot of moisture and a tight heavy snowfall gradient, staying tuned to later forecast updates is prudent. &&

URGENT - WINTER WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 602 PM EST Sat Dec 8 2018 VAZ025-037-090715- /O.UPG.KLWX.WS.A.0007.181209T1100Z-181210T0500Z/ /O.NEW.KLWX.WW.Y.0027.181209T1100Z-181210T0500Z/ Augusta-Albemarle- 602 PM EST Sat Dec 8 2018 ...WINTER WEATHER ADVISORY IN EFFECT FROM 6 AM SUNDAY TO MIDNIGHT EST SUNDAY NIGHT... * WHAT...Snow expected with accumulations around 2 to 5 inches. * WHERE...Augusta and Albemarle Counties. * WHEN...From 6 AM Sunday to midnight EST Sunday night. * ADDITIONAL DETAILS...Plan on slippery road conditions.

URGENT - WINTER WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 602 PM EST Sat Dec 8 2018 VAZ036-508-090715- /O.UPG.KLWX.WS.A.0007.181209T1100Z-181210T0500Z/ /O.NEW.KLWX.WS.W.0011.181209T1100Z-181210T0500Z/ Nelson-Central Virginia Blue Ridge- 602 PM EST Sat Dec 8 2018 ...WINTER STORM WARNING IN EFFECT FROM 6 AM SUNDAY TO MIDNIGHT EST SUNDAY NIGHT... * WHAT...Snow expected with accumulations around 3 to 6 inches. * WHERE...Nelson County, and Central Virginia Blue Ridge. * WHEN...From 6 AM Sunday to midnight EST Sunday night. The heaviest snow will be Sunday afternoon and early evening. * ADDITIONAL DETAILS...Plan on snow covered and slippery roads. Travel will be difficult.

I think most of us south of DCA but north of EZF know around an inch is what we should be looking for at best. If we get more, so be it. If it's a dusting or just flurries, oh well, its snowing

According to Ji yup

Actually, a bit of a south jog with the QPF field

18z RGEM still looks good... waiting on QPF total

See you at 00z

Maybe not for you, but for the southern part of the LWX CWA yes it does

Comparing 12z total QPF at 36 to 18z at 30

Looks like 6" or so at EZF this run? wow...

Just as an FYI for us... AKQ has gone WSWatch for the counties bordering the LWX southern zones (aka around EZF) URGENT - WINTER WEATHER MESSAGE National Weather Service Wakefield VA 250 PM EST Sat Dec 8 2018 VAZ048-061-062-068-069-509>516-090400- /O.NEW.KAKQ.WS.A.0004.181209T1200Z-181210T0900Z/ Fluvanna-Cumberland-Goochland-Amelia-Powhatan-Western Louisa- Eastern Louisa-Western Hanover-Eastern Hanover- Western Chesterfield- Eastern Chesterfield (Including Col. Heights)- Western Henrico (Including the City of Richmond)-Eastern Henrico- Including the cities of Bybee, Central Plains, Cunningham, Lake Monticello, Nahor, Palmyra, Troy, Angola, Guinea Mills, Hawk, Raines Tavern, Reeds, Stoddert, Goochland, Earls, Mannboro, Scotts Fork, Amelia Courthouse, Chula, Denaro, Jetersville, Fine Creek Mills, Flat Rock, Goodwins Store, Subletts, Worshams, Clayville, Genito, Louisa, Mineral, Ashland, Mechanicsville, Bon Air, Midlothian, Chesterfield, Chester, Colonial Heights, Richmond, and Sandston 250 PM EST Sat Dec 8 2018 ...WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH LATE SUNDAY NIGHT... * WHAT...Wet snow, moderate to heavy at times will develop Sunday morning and continue through the day. The snow may mix with rain at times, especially closer to I-95, as temperatures rise above freezing. Total snow accumulations of 3 to 6 inches. Some light icing is possible Sunday night as temperatures drop below freezing. * WHERE...Portions of central Virginia including the Richmond Metro. * WHEN...From Sunday morning through late Sunday night.

Chance of snow? Chance of accumulation?

It begins URGENT - WINTER WEATHER MESSAGE National Weather Service Baltimore MD/Washington DC 205 PM EST Sat Dec 8 2018 VAZ025-036-037-508-090315- /O.NEW.KLWX.WS.A.0007.181209T1100Z-181210T0500Z/ Augusta-Nelson-Albemarle-Central Virginia Blue Ridge- 205 PM EST Sat Dec 8 2018 ...WINTER STORM WATCH IN EFFECT FROM SUNDAY MORNING THROUGH SUNDAY EVENING... * WHAT...Snowfall accumulations of 5 inches or more possible. * WHERE...Augusta, Nelson and Albemarle Counties, and the central Virginia Blue Ridge. * WHEN...From Sunday morning through Sunday evening. * ADDITIONAL DETAILS...If this threat materializes, travel could be very difficult or nearly impossible. There will be a tight gradient between very little to no snow to the north and more significant amounts of several inches to the south, with any subtle shift in track resulting in possibly significant variations in snowfall over relatively short distances.

This shows Ian's tweet a lil better... from one of our NYC brethren on twitter

Banned

That's a good shift north I believe, yes?

That is correct good sir

Euro should be north a bit seeing 24 hours

Going to guess DCA is 0.1 to 0.15 for the 12z UKMET on the QPF... waiting for meteogram... unless someone else has the image already For comparison, 00z UKIE had nothing in DCA

Decent shift north with QPF field by 12z UKIE

Brutal cutoff... Leesburg flurries and EZF 10"

12z JMA is good to go lol

Interesting... 00z FV3 gets 0.05" QPF line to S Fairfax and 0.01" QPF line just north of DC EZF into S MD ~0.20-0.25" QPF