Heavy Rainfall Expected Monday through Tuesday Combination of Stalled Frontal Systems and Outer Effects of Tropical Storm Isaias

Significant amounts of rainfall are expected to begin across the
forecast area after midnight tonight and increase through the day
Monday into Tuesday as a result of a stalled frontal system across
the area, firmly entrenched deep tropical moisture, and the outer
circulation of now Tropical Storm Isaias moving northward from
along the central and northern Florida East Coast today to just
east of Danville by Tuesday morning. Upslope east flow along the
Blue Ridge later tonight and Monday combined with an increasing
fetch of tropical moisture associated with the outer circulation
of Isaias as it moves northward and then further enhanced with
disturbances aloft and the proximity of the stalled frontal system
over the area could lead to excessive amounts of rainfall across
parts of the forecast area. One area that seems likely to see
excessive amounts of rain, in the 2-4 inch range, are the eastern
slopes of Blue Ridge Mountains, particularly from Watauga County
NC northeastward toward Patrick County VA, or roughly from Boone
NC to Meadows of Dan VA. The other area that could see excessive
amounts of rain will be Southside Virginia into the Virginia and
North Carolina Piedmont or roughly the Danville, Lynchburg,
Martinsville, and Reidsville areas as the core of Isaias passes
just east of Danville early Tuesday. In these areas, 2-4 inches of
rain are likely through Tuesday with locally higher amounts. Most
of the rain in this area will occur Monday afternoon through
Tuesday morning.

The ground across much of the region is saturated from recent
rainfall and thunderstorms. The amount of rainfall needed to
initiate flash flooding or flooding in these areas is lower than
normal for this time of year. Thus flooding and flash flooding
could begin quickly once persistent and moderate to heavy rainfall
commences later tonight and Monday.

Small creeks and streams could rise into flood quickly by Monday
afternoon in areas of heavy rainfall. The Watauga River and its
tributaries in western NC will be subject to flooding as early as
Monday morning. Larger main stem river flooding is less likely,
but at least minor flooding could be expected on the Dan River
basin and its tributaries later in the week.

Ashe-Alleghany NC-Surry-Watauga-Wilkes-Grayson-Carroll-Floyd-
Including the cities of West Jefferson, Sparta, Dobson, Boone,
Wilkesboro, Independence, Whitetop, Troutdale, Volney, Galax,
Floyd, and Stuart
455 AM EDT Sun Aug 2 2020


The National Weather Service in Blacksburg has issued a

* Flash Flood Watch for portions of North Carolina and southwest
Virginia, including the following areas, in North Carolina,
Alleghany NC, Ashe, Surry, Watauga, and Wilkes. In southwest
Virginia, Carroll, Floyd, Grayson, and Patrick.

* From Monday morning through Tuesday evening

* Excessive rainfall enhanced by the remnants of Tropical Storm

* Small creeks and streams could rise into flood quickly on
Monday. Flash flooding can be expected in areas of quick heavy
rainfall and areas of persistent moderate or heavier rainfall.
From 2 to 4 inches of rainfall is expected in the included
counties, with locally higher amounts possible along the
southern Blue Ridge from northwest North Carolina into far
southwest Virginia.


A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a VERY DANGEROUS SITUATION.

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.