UPDATE 4:25 PM, 8/13/2019: Stable air and drier westerly downslope winds have effectively ended the threat of strong to severe storms along the U.S. 460 corridor through the New River and Roanoke valleys, with the storms having formed in more unstable, hot, sticky air to the south and pushed southeastward. A few scattered showers or an isolated storm can't entirely be ruled out through the evening, but it appears this severe risk has moved away. END UPDATE
UPDATE 11:55 PM, 8/13/2019: Morning rain and storms have stabilized the atmosphere in many locations north of Roanoke, but the sun is out with heat and instability building to the south and east. So the threat of scattered strong to severe storms developing remains during the afternoon and evening, especially along and south of U.S. 460 -- the highway connecting Blacksburg, Christiansburg, Roanoke, Bedford and Lynchburg. Morning cloud cover and a quick morning storm in the Roanoke Valley may keep us below previously projected highs in the mid 90s, but it may yet get close to 90 with plenty of sticky humidity. Do not be surprised if a severe thunderstorm watch is issued later this afternoon for much of our region. END UPDATE
Heat and humidity will be on the rebound on this Monday, with some spots in the Roanoke Valley and points south and east getting to near 90, and a few afternoon thunderstorms popping up. But the temperature, dew points and thunderstorm chances will reach a crescendo on Tuesday. when some highs in the mid 90s and severe thunderstorms are possible.
A cold front is sliding southeastward. This will ultimately lead to another period of slightly cooler and less humid conditions for late week into the early part of the weekend, but its first impact will be increasing chances of thunderstorms ahead of it, and the potential for some of those thunderstorms to be severe, with locally damaging winds, hail and perhaps a tornado or two in the Mid-Atlantic and central/southern Appalachians region on Tuesday.
Generally, the greater chances of severe storms will be to our north, over Northern Virginia and portions of adjacent states, where atmospheric shear will be stronger. But some storms may also become severe down this way too. It is unclear at this point if storms will form a squall line, remain more scattered, form one or more clusters, or some combination of these.
Tuesday's storms will not be a widespread solution to any dry-weather issues -- per the typical, there will be some heavy downpours in spots, more spots getting lighter amounts, and other missing the rain entirely.
The front hangs up a bit south of us on Wednesday, with some lingering showers, but eventually gets enough a push south and east to free us up for some mostly sunny, dry, not-quite-as-warm days late in the week, with 80s highs and 60s lows common.
At this point, it remains the case that there is no obvious major heat wave, sharp cooldown or widespread, soaking rain on the horizon, over the next 7-10 days at least. Rather, it appears our temperatures will be close to normal (generally 80s for highs, 60s for lows), bouncing above that on occasion, then pulled back by passing fronts that bring periods of increased, but still scattered, showers and storms. Summer hasn't let go, but isn't searing us with its worst.