UPDATE 7:30 AM, 10/30: Sandy inland; windy weather continues in SW Virginia, with some rain and snow
UPDATE 7:30 AM: I will be working on a new blog post soon. The worst is over for Southwest Virginia, but winds may still gust locally to over 50 mph at times today, so the high wind warning remains in effect, and there may be a few snow or rain showers blowing in that wind (a few flurries out my window just south of Roanoke this morning). The center of the massive circulation of what was once Hurricane Sandy will drift west through Pennsylvania today, then northward on Wednesday, with winds still gusty but gradually decreasing. END UPDATE
UPDATE 12:30 AM, 10/30: Roanoke has continued to record several 50-plus gusts in the past 3 hours, with sustained winds 26-33 mph. Power outages remain scattered, but continue to grow in number in the Roanoke and New River Valleys and nearby areas — thousands are losing power with heavy wet snow in West Virginia and far Southwest Virginia. Expect similar and winds and gusts through Tuesday morning, before a gradual lessening of the wind as Sandy slows her inland motion and then drifts north. Some snow showers may continue in the higher elevations and west of Roanoke. END UPDATE
UPDATE 10:45 PM: Just before 10 p.m., a 60 mph gust was recorded at Roanoke Regional Airport, with sustained winds now topping 30 mph. The map linked here vividly illustrates the surface wind flow over the U.S., swirling around SandySuperstorm in the East. END UPDATE
UPDATE 9 PM: The National Weather Service in Blacksburg has extended the winter weather advisory to include elevations above 2,500 feet in Wythe, Pulaski, Montgomery, Carroll and Floyd counties, with 2-5 inches possible in those areas. … Nearly 2,000 power outages in the localites around Roanoke with several thousand in Tazewell County and southern West Virginia. Click here for Appalachian Power’s latest outage map. END UPDATE
Hybrid hurricane-extratropical storm Sandy — the strongest ever storm as measured by low barometric pressure in the recorded history of the East Coast north of Cape Hatteras — is nearing landfall in the Delaware Bay area. While the brunt of its impact will of course slam the Mid-Atlantic and Northeast coastal areas with wind, heavy rain and waves over an enormous area, impacts in the inland East and Appalachians will ratchet upward through the evening. In Southwest Virginia, first and foremost, this will mean strong and gusty winds. They have been gradually picking up through the day, working from higher elevations downward and also east to west, but will pick up more as the center of Sandy (I’m keeping this name for easy reference) moves inland and closer to our region. Understand that this is far from a typical hurricane landfall, where the winds of the storm might be confined to a couple hundred miles from its center. As a large hurricane-nor’easter hybrid storm, energized by a strong jet stream dipping from the Arctic Circle, Sandy’s strong winds extend many hundreds of miles from its center. In our area, the wind is augmented by the mountain topography causing strong winds to break into waves that can crash into valley areas as well. So that’s why we have a high wind threat this far away from Sandy — and already more than 1,000 power outages locally with just the increase we’ve seen. These winds will not be the quick blast of the derecho that occurred four months ago today, but periods of gusts throughout the night and into Tuesday, sustained at 20-40 mph with top gusts near 60 mph possible. We do normally get 2 to 4 high wind warnings each winter from Arctic frontal passages — I would rate this a notch or two higher than most of those for intensity and it will also be longer in duration than most, with some gusty winds possibly lingering into Wednesday. Scattered damage and additional power outages are just about assured. At this time, I don’t think they will be as widespread in our area as during the derecho.
(Photo at left from road to Mountain Lake in Giles County, taken by Matt Gentry of The Roanoke Times). There will also be periods of rain and snow intermittently through the night. Moisture rotating around Sandy is expected to dry up some headed south as it encounters downslope wind flow over the mountains. This will likely limit the amounts of either rain or snow that falls east of I-77 and the ridges along the Virginia-West Virginia line and south of I-64 in our region. Still, a few bursts of heavier snow could collect on grassy areas and exposed objects at elevations above 2,000 feet or so, and there is a chance snow will penetrate a little lower at times during the night, maybe even all the way down to Roanoke for a time. It does NOT appear at this time that moisture will be thick enough or cold air deep enough for a long enough duration of snowfall for widespread heavy accumulations in the New River or Roanoke Valleys, or along the Blue Ridge excluding perhaps the highest peaks (Peaks of Otter, Mount Rogers, Poor Mountain, etc.). It’s much different closer to the thick moisture flow, with blizzard warnings above 2,000 feet along the I-64 corridor and northward, and of course in West Virginia and the part of Virginia west of I-77, where many inches to a couple of feet will fall. In our area, elevation-dependent winter storm warnings and winter weather advisories continue for some counties along the West Virginia border (Bland, Giles, Craig, Alleghany, Bath), those west of I-77 (Tazewell, Smyth, Grayson and westward), and for Rockbridge and Amherst just south of the I-64 blizzard warnings.
This is a somewhat fluid and uncertain situation with an unprecedented storm, so this could certainly need some tweaking as the night goes along. I’m sure I’ll hear from you with your reports if snow begins falling or sticking where it hasn’t previously.