UPDATE 6 PM: Wind-downed trees block several roads in Bedford and Franklin counties. END UPDATE
UPDATE 2:40 PM: TORNADO WATCH ISSUED FRANKLIN, BEDFORD COUNTIES AND EASTWARD. Heavy rain/storms will be moving into New River/Roanoke valleys next 2-3 hours. END UPDATE
UPDATE 1:30 PM: Storm Prediction Center says there is 80 percent chance of a tornado watch being issued this afternoon east of the Blue Ridge. Roanoke on western edge of area being considered for tornado watch. END UPDATE
This wall of clouds and moisture shown on the late Thursday evening satellite will be marching our way on Friday. It represents a vigorous cold front lifting moisture from the Gulf of Mexico moisture upward, condensing it into a line of rain and thunderstorms. While it would fall short of the major severe weather outbreak that was at least somewhat feared, there have been several reports of high winds, large hail and tornadoes both Wednesday and Thursday as it has made its way through the central U.S. For Southwest Virginia, it will also likely NOT be a major severe weather outbreak, but some storms with strong winds are possible, and an isolated weak, brief tornado or two can’t entirely be ruled out. The risk appears to be a notch or two higher than it was 8 days ago, when it was confined mostly to a few wind damage reports in the counties along the North Carolina state line. Moisture is thicker this time and it will be moving through during the warmer daylight hours, rather than late at night. Also, there may be a bit more shear, with surface winds from the southeast or south-southeast gradually shifting to southwesterly winds high in the atmosphere. A limiting factor for severe storms, however, will be the likelihood that those winds bank moisture against the mountains early in the day, leading to clouds and showers that will stall daytime heating and thereby reduce atmospheric instability. Many forecast models suggest areas east of the Blue Ridge, particularly from Southside to Hampton Roads and southward into the Carolinas, will have the highest chance of seeing supercells (rotating thunderstorms) with the possiblity of producing large hail and perhaps a few tornadoes. Timing of the system appears to bring the best chance of heavy rain and storms into and through Southwest Virginia east of I-77 between noon and 6 p.m. Showers and storms are already moving into far southwest Virginia as of 9 a.m. (UPDATED) This may need some refining as the situation develops on Friday. Many parts of Southwest Virginia may see rainfall amounts approaching an inch, with some locally heavier amounts.
Once the front clears, a cool but dry weekend will break out. Temperatures on Saturday will be in the 40s and 50s most of the day, possibly cracking 60 in some spots with afternoon sun. Sunday and Monday mornings may be a bit frosty, especially in outlying areas, with some freezing temperatures possible. The next 7-10 days, perhaps 2 weeks, are likely to average below seasonal temperature norms (normals for late April are generally upper 60s/low 70s highs and mid-upper 40s lows for Roanoke; chop about 5 degrees off that for Blacksburg), with brief warmups interspersed by Canadian cold frontal passages.