You can never let your guard down with low pressure systems in March.
A coastal storm drenched central Virginia on Thursday while delivering a surprise thump of snow to the Blue Ridge Mountains.
Several inches of wet snow piled up in Shenandoah National Park by the afternoon, forcing all of Skyline Drive to close and stranding motorists on U.S. 33 between Stanardsville and Elkton. The highest reported snowfall was at Wintergreen, which had 8 inches by 3:45 p.m.
Interstate 64 was passable at Afton Mountain, where cameras showed snow sticking to everything but the travel lanes.
Flakes made it down to valley level between Staunton and Harrisonburg, but it amounted to a light coating on grass. Roads mostly stayed wet, according to the Virginia Department of Transportation.
At lower elevations, rainwater flooded roads at dozens of points from the Charlottesville region into Northern Virginia.
The reason for the sneaky winter storm was twofold.
The low pressure system was more potent and veered farther to the west than it seemed it would earlier in the week, thanks to a favorable configuration of winds in the jet stream.
It intensified as it tracked northward from Cape Fear, N.C., to eastern Virginia on Thursday, and it will continue to strengthen as it spins into the Northeastern states on Friday.
Then, the high-elevation snowfall came about due to a process called dynamic cooling.
The heavy rate of the precipitation cooled the air it was falling into, to the point that it was cold enough for snow in the mountains.
Ridgetops are most susceptible to getting snow that way because they’re already cooler, but it’s been known to cause snow to sneak into central Virginia.
Another soggy day
Central Virginia didn’t see any snow, only a return to unwelcome rainfall.
By Thursday afternoon, several roads in the western part of Chesterfield County were covered with standing water, according to VDOT.
About 4 p.m., Chesterfield Fire & EMS said Otterdale Road would be closed at Duval Road until further notice due to high water.
There were scattered reports of road disruption from most counties in central Virginia.
By 6 p.m., rainfall totals ranged from 1 inch on the east side of the metro area to 2 inches on the west side.
Richmond International Airport picked up nearly 1.5 inches from Wednesday evening into Thursday afternoon.
A gauge north of Midlothian led the area totals with 2.16 inches.
An interesting consequence of the low’s trajectory through the region was a sharp temperature contrast. Areas east of Interstate 95 managed to reach the lower 60s, with rain-cooled 40s and 30s to the west.
The temperature at Richmond International Airport fell from 57 degrees at 1:50 p.m. to 48 at 2 p.m., an abrupt tumble as winds switched from easterly to northwesterly.
Expect Friday’s weather to be clearing and warmer but noticeably breezy, with some gusts from the west up to 35 mph in central Virginia. Scattered, brief rain squalls can’t be ruled out during the afternoon as a cold front passes through. Highs should make it into the upper 50s or lower 60s.
Fair weather will prevail over the weekend, with morning lows near freezing but pleasant highs near 60 on Saturday and possibly up to 70 on Sunday.
More rain moves into the picture from Monday into Tuesday, but for now it doesn’t look to be as heavy as the most recent storm.
Shenandoah National Park started out by seeing the predicted rain on Thursday morning, but unexpected snowflakes appeared by midmorning, according to public information officer Claire Comer.
“It was falling fast and furious and accumulating really quickly,” said Comer, who had to leave a van behind and inch down the mountains in someone else’s high-clearance vehicle.
At least 2 inches of snow were on the ground at the time, but there wasn’t an official measurement from the area.
About 12:30 p.m., the National Weather Service in Sterling issued a winter storm warning for the crest of the Blue Ridge from Montebello to Chester Gap, highlighting the potential for up to 6 inches by the evening.
Webcams at Big Meadows showed snow piled up neatly on tree branches and evenly coating the ground.
Winter’s wind and ice have been harsh on the state’s higher elevations, and the disruption isn’t over yet.
Falling branches and trees have been a big problem for roads, trails and campgrounds along the Blue Ridge Mountains.
Crews are in the process of removing tree debris from a 40-mile portion of Skyline Drive that had been closed since an ice storm in November.
“We’re working like crazy to get the campgrounds cleared to get them open at the end of this month,” Comer said.
Drier weather will return as the latest storm exits to the northeast on Friday, but gusty winds wrapping in from the northwest could cause more trees to topple in the wet ground.
Shenandoah National Park itself remains open, but the status of Skyline Drive is questionable going into this weekend due to the potential for falling trees.
Visitors should call ahead to (540) 999-3500, option 1 to hear the latest travel conditions, or check the park’s website and social media.
James River levels
Runoff from this system will push the James River close to minor flood stage, according to the National Weather Service in Wakefield.
The stage at the Westham gauge was nearly 7 feet on Thursday afternoon. It was predicted to crest at 11.7 feet early Saturday morning. Minor flooding occurs at 12 feet.
Minor flooding is also expected for the Rivanna River at Palmyra and the Meherrin River near Lawrenceville on Friday.