... A cold front advances to the coast tonight. A wave of low pressure is expected to develop along the front tonight before moving off the Mid- Atlantic coast Wednesday. Another storm system will impact the region for the end of the week.
NEAR TERM /UNTIL 6 PM THIS EVENING/... As of 1136 PM EST Tuesday...
Appears back edge of snow will be moving across the mountains between midnight and 3am, and will not be snowing all the time, but in bands. Each band will be capable of putting down an quick half inch, but overall snow totals will be in the 1-2 inch range, with some locally higher amounts of 3-4 inches possible especially across the mountain empire in the higher ridges.
Further east, snow is going to be an inch or less on grassy surfaces. Will leave headlines as is.
Forecast was adjusted to lower pops sooner in the mountains.
Previous discussion from early Tuesday evening...
Adjusted temps down in the west as colder air starting infiltrate faster and snow making it as far east as the WV/VA border, but no accumulations yet. Radar coverage overall is patchy/spotty/bandy in nature, and the latest HRRR and RAP showing this a bit better than the 18z Nested NAM. Very little accumulation will occur early given wet/milder ground, but as temperatures sink through the 20s overnight we expect accumulations on grassy and roads to occur. The low levels per forecast soundings depict limited threat of freezing rain in the mountains of WV and far SW VA so dropped that out. Mainly a rain to snow scenario possibly some light sleet/freezing rain along the Blue Ridge.
Do not foresee any changes to snow amounts or headlines as latest models depict better accumulations in the higher elevations of far SW VA with less to the east, but this is contingent on how any stronger banding if any occurs with secondary wave of low pressure forming along the front.
Previous discussion from earlier this afternoon... Posted a winter weather advisory for this evening into Wednesday morning for a wintery mixture of snow, sleet and freezing rain.
Cold air will transition moisture (rain) along and behind the cold front this evening into Wednesday morning into a wintry mixture of snow, sleet and freezing. Snow accumulations of one to three inches are possible especially in the higher elevations. A light glaze of ice is possible especially along the southern Blue Ridge mountains. The best chance of the ice will be on elevated surfaces. Low temperatures tonight will be in the upper teens in the northwest mountains in Greenbrier county to the mid 30s in the piedmont.
Lingering precipitation behind frontal boundary Wednesday will rapidly taper off from west to east Wednesday morning with some wet flakes making it a bit east of the Blue Ridge as precipitation ends. A large area of high pressure will build east from the Tennessee valley Wednesday. High temperatures Wednesday will be the mid 20s in the northern mountains to the upper 40s in the piedmont.
SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... As of 255 AM EST Wednesday...
Our brief respite of quiet weather will continue through Thursday before our next wintry system begins to affect the region Thursday night.
Guidance remains fairly consistent in depicting system evolution. Cold high pressure will remain wedged down the east side of the mountains as a developing coastal low spreads precipitation into the region from the south late Thursday night. Indications of the temperature profile from Bufkit are that the favored ptype will be freezing rain with some sleet/snow mixed in for a brief time at the onset. With the coastal low pushing a good amount of precipitation over the wedge, expect most locations will see a decent glaze of ice by Friday morning, with a gradual transition to plain rain Friday afternoon though pockets of freezing rain will likely linger for a bit longer. May see ice accumulations of one to two tenths especially for portions of the Roanoke and New River valleys northward, with little if any ice for far eastern portions of Southside. While confidence is rising in the potential for freezing rain, confidence in actual ice accumulations remains low. Expect transition to a plain rain scenario for Friday night into Saturday.
As the coastal low moves up into coastal New England, colder air and moisture will wrap around the circulation and generate upslope precipitation west of the Blue Ridge later Saturday into Saturday night with a gradual transition back to snow showers at the higher elevations later Saturday night with the arrival of colder air. The low level wind field will amplify with the arrival of the colder air with windy conditions and some strong gusts expected.
Temperatures will be running below normal in the wedge through the end of the week with readings lingering in the 30s on Friday. Will see a brief warm up on Saturday before the arrival of colder air Saturday night. Expect to see some low/mid 50s Saturday east of the Blue Ridge with generally middle 40s to the west.
LONG TERM /SUNDAY THROUGH TUESDAY/... As of 230 PM EST Tuesday...
Long wave trough will be crossing the eastern United States through Sunday. Monday the Mid Atlantic region will be in broad southwest 500MB flow between ridging the western Atlantic and troughing over the central United States. This through arrives in the East on Tuesday.
At the surface, high pressure follows for Sunday. Monday a low develops on the front in the Southern Plains which reaches the Mid Atlantic and Southeast United States on Monday and Tuesday. Strong jet diffluence Monday and Tuesday will result in prolonged widespread precipitation.