UPDATE 10 AM, 1/31: The New River at Radford is nearing an expected crest of 21 feet — major flood stage, swamping vehicles at Radford University — and the Roanoke River is nearing an expected crest just above 12 feet at Walnut Avenue, 2 feet above flood stage, a low-end “moderate” flood. These rivers will be receding upstream from these points, and rising downstream, through the day, as widespread 2-6 inches of rain (and some higher amounts) continues to drain off of steep terrain and saturated soil. Hundreds of roads are closed by flooding statewide. It appears to be our region’s worst widespread flooding event at least since late June 2006 and possibly since the triple-tropical-trouble (Frances-Ivan-Jeanne) of September 2004. END UPDATE
UPDATE 12:05 AM, 1/31: The bulk of the rain is pulling east of Roanoke as I type this, with some showers remaining for the rest of the evening — and some windy, colder weather. Snowflakes may even fly in some locations, especially west of Roanoke and in higher elevations. The large amounts of water dumped on already wet ground will continue to runoff, with flooding on streams and some rivers continuing today, including the New and Roanoke rivers. A quick-moving disturbance from the northwest will bring a chance of light snow or snow showers into the area late Thursday night and early Friday, and a similar system may cause a second round late Saturday night and Sunday. We’ll plan to take a closer look at that on Thursday afternoon. END UPDATE
The severe storm threat has passed with the departure of the squall line (with considerable damage in Pulaski County), but the heavy rain/flooding threat is ongoing, with numerous flash flood warnings affecting the Roanoke and New River valleys and much of Western and Southwest Virginia. Moderate to heavy rain is likely to continue for another 3-5 hours over most of the region, with many areas already over an inch, and some already topping 4 inches, especially near the North Carolina border. This rain is falling onto soil that has become saturated from substantial rain and snow since Jan. 14, so much of it is running off into drainages and streams. Beware if traveling tonight for ponding on the roads or, even, creeks and rivers rising out of their banks across roadways.
Colder air will be moving in on Thursday behind an Arctic cold front and a series of Alberta clipper systems will bring chances of light snow through the weekend, with the better chances west of Roanoke.