Flash Flood Threat Continues This Morning Across the Foothills and Mountains

If you’ve looked outside this morning, you’ve probably noticed the steady rain and slow-moving downpours. Additionally, streams and creeks are swollen from overnight heavy rainfall. Currently, the flood advisories have expired across the majority of the foothills. The one exception is Surry and Wilkes County, where a Flash Flood Warning is ongoing. Unfortunately, the weather pattern responsible for yesterday’s flooding concerns hasn’t changed much, and the threat for additional flash flooding will continue through much of the morning.

A stubborn upper-level low spinning over the Tennessee Valley continues to funnel moisture into western North Carolina. At the same time, winds a few thousand feet above the ground are pushing that moisture directly into the eastern slopes of the Blue Ridge. When that happens, the mountains force the air upward, squeezing out even more rainfall. This process, known as upslope flow, is one of the main reasons our area can experience heavy rain for hours while locations farther east see much less.

The atmosphere remains loaded with tropical moisture, with nearly two inches of precipitable water available. Even though instability has decreased somewhat since overnight, there is still enough energy in the atmosphere to produce slow-moving showers and thunderstorms capable of very heavy rainfall.

Rainfall rates of 1 to 2 inches per hour remain possible underneath the heaviest cells. Because these storms are moving very slowly and may repeatedly develop over the same areas, isolated areas could still pick up an additional 3 to 4 inches of rain before activity diminishes later today.

The greatest concern continues to be across the mountains, foothills, and along the Blue Ridge escarpment, where upslope flow enhances rainfall. Creeks and streams can rise quickly, especially in areas that received heavy rain overnight. Roads that normally flood may become impassable with little warning.

While this isn’t expected to be a widespread flooding event, the localized nature of these storms means one community could see only light rain while another, a few miles away, experiences dangerous flash flooding.

If you’re traveling this morning, remain alert for water covering roadways. Remember, it only takes a small amount of moving water to sweep away a vehicle. If you encounter a flooded road, Turn Around, don’t drown.

We’ll continue monitoring radar trends throughout the morning and provide updates if flash flood warnings become necessary.