UPDATE 7 PM, 4/22: Historic spring snowstorm set to hammer W.Va., Pa. — and SW Virginia may get a sliver of it, too
UPDATE 7:15 pM, 4/22: Snow is well under way in the high country of West Virginia, as can be seen by this live web cam at Snowshoe Mountain. A coastal low pressure system is rapidly deepening off the Outer Banks, as new upper-level energy arrives from the west. The National Weather Service in Blacksburg opted for winter weather advisories in Bath County, Va., and across the line in Greenbrier County, W.Va., with winter storm warnings from other forecast offices starting just to the north in Pocahontas County, W.Va., and extending northward to just east of Pittsburgh and beyond. Forecast guidance suggests elevation-dependent accumulations of 2-5 inches, with some locally higher amounts on the highest ridges, in the winter weather advisory areas. Some snow may also fall farther south, with some flakes probably falling in the New River Valley by the early morning hours and maybe a few even in parts of the Roanoke Valley. Light accumulations are possible in some spots, mainly grassy areas and higher elevations, but Southwest Virginia will mostly miss out on the heaviest part of this spring snowstorm. END UPDATE
UPDATE 10 AM, 4/22: A winter storm watch has been issued for Bath County in Virginia and Greenbrier County in West Virginia, at the southern end of a stretch of counties under a winter storm watch extending north into Pennsylvania. Accumulations of 6 or more inches are possible at 2,500 foot and higher elevations in those counties, with 1-3 inches at lower elevations. END UPDATE
An October snowstorm that knocked out power for millions from I-64 in Virginia to Maine. Our second-warmest winter on record. A 5-to-9-inch snowstorm in February one day after highs in the 60s. An early March clipper system that whitened most areas north and west of Roanoke, and covered fresh tornado debris with snow in Kentucky. The warmest March on record, not just locally, but nationally. And now, a really flaky twist — the growing likelihood for a historic central and northern Appalachian late April snowstorm, of which Southwest Virginia may experience a fringe.
A rapidly strengthening low-pressure sytem climbing the East Coast today will spread a chilly rain over most of Virginia. As of late this Saturday evening, 1/2 to 1 inch amounts of rain are projected east of the I-77 corridor. High temperatures in the 40s to low 50s will be early in the day, with temperatures slowly falling through the day. As that low deepens even more Sunday night and Monday, and gets pulled slightly inland to the northwest by the south-dipping jet stream trough, it will wrap in even more cold air behind it and fling additional moisture around it into that cold air. That will very likely lead to a historic late April snowstorm in much of eastern West Virginia and western Pennsylvania. As you can see by the Hydrometeorological Prediction Center’s map Saturday evening of 4-plus-inch snowfall potential, western Virginia is literally on the lip of that heavy snow potential, with a slight risk of 4-plus inches poking just barely across the state line into the western fringe of counties like Giles, Craig, Alleghany and Bath. It’s highly probable that the ridgetops of Salt Pond Mountain (Mountain Lake area), Potts Mountain (yes, where they had a wildfire last week) and other 3,000-foot-plus elevations along the Virginia-West Virginia will be white — maybe deeply white in spots — come Monday morning. The mountains west of the I-77 corridor down into northwest North Carolina also may get some significant snowfall, especially at higher elevations. There are some growing indications that snowflakes will also spray into the New River Valley as rain starts to wind down late Sunday and early Monday, and some snow showers in the Roanoke Valley or even the Piedmont counties cannot entirely be ruled out. (Weather service map linked here details current expectations of snow coverage overnight and Monday.) Downsloping winds tend to dry out, and it’s often especially hard in spring to cool that last thin layer near the ground enough for snow to develop. But this is a deeply dynamic storm system, and we’ll need to watch the situation closely as it develops Sunday evening just in case there is a greater chance than we think now that heavier snow might get pulled a little farther east or a little lower in elevation. A few inches of wet snow in any area, combined with unusually early leafed-out trees and the potential for gusty winds, will create the potential for tree damage and power outages — a grim prospect that parts of West Virginia and Pennyslvania are very likely facing. As is the case most of the time, the higher up you are, the farther west you are, the more chance you have of seeing significant snow with this event. Monday will be an unbelievably wintry day to be April 23 on the calendar in the high country of West Virginia — probably near whiteout conditions at times around Snowshoe and Canaan Valley.
Strong winds developing as the low tightens may due some damage to trees and knock out some power on Monday without any help from wet snow. Well-below-normal temperatures — 40s/50s for highs, 20s/30s for lows — will settle in until midweek, and only gradually modify after that. That hot March we had will be a distant memory for a few chilly days in late April.