Area Forecast Discussion
Issued by NWS Blacksburg, VA
Issued by NWS Blacksburg, VA
412 FXUS61 KRNK 171032 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 632 AM EDT Mon Aug 17 2026 .WHAT HAS CHANGED... Flood Watch is continued for portions of SE West Virginia and west central Virginia. Aviation forecast updated. && .KEY MESSAGES... 1) Frontal boundary will bring shower and thunderstorm chances that may cause strong to severe winds and localized flash flooding to the area. 2) Dry weather returns Tuesday, with the next rain chances forecast Thursday through Saturday. && .DISCUSSION... KEY MESSAGE 1... Frontal boundary will bring shower and thunderstorm chances that may cause strong to severe winds and localized flash flooding to the area. A cold front looks to push through the area late tonight, which will lead to showers and thunderstorms for areas along and south of the 460 corridor. The environment out ahead of these storms looks favorable for strong to severe winds as SBCAPE values look to increase to around 2000-2500 J/Kg, DCAPE values will increase to around 700-900 J/Kg, and deep layer shear in the 0-6 Km layer looks to increase across the area to around 25-30 knots. This deep layer shear will be enough to help develop multicellular clusters and an isolated supercell thunderstorm or two this afternoon along the frontal boundary. overall, low level shear looks to be rather weak, which will keep the threat for any tornadoes to a minimum, with no SPC threat forecast. Given the parameters above, the largest threat will be severe winds with the stronger storms that develop. Along with a severe threat, PWATs in the 1.7-2.1 inch range will continue to lead to a localized flash flood threat where the heaviest thunderstorms develop. Training storms may bring repeated rounds of heavy rainfall, which can quickly fill local streams leading to flooding of roadways and urban areas. Rainfall rates in the 3-6 inch per hour range may also quickly aid in flash flooding occurring today with these thunderstorms. KEY MESSAGE 2... Dry weather returns Tuesday, with the next rain chances forecast Thursday through Saturday. Behind the passage of a cold front on Monday, drier air is expected to advect into the region. This will lead to significantly reduced shower and thunderstorm chances, with near zero chances forecast Tuesday and Wednesday for the area. An upper level trough and additional cold front pushes into the area late Thursday, which looks to bring shower and thunderstorm chances back into the region. Temperatures also look to return to seasonal values as this upper level trough effectively returns the upper level ridge back west into the western Conus by the end of next week. The aforementioned frontal boundary does look to get hung up across the region through Saturday, leading to scattered rain and thunderstorm chances daily starting Thursday once again. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... With the late night rainfall for much of the area, the region has so far remained fog and low CIG free this morning, with only some MVFR CIGs and VSBYs developing at LWB and LYH. These restrictions should lift quite quickly after 12 UTC this morning. Chances for SHRA/TSRA will return today for most terminals along and south of 460, with ROA and LYH possibly not seeing high enough chances to include in a TAF line at this time. These showers and thunderstorms may lead to brief periods of restrictions plus erratic winds if they move over or within the vicinity of a terminal. Winds today will predominantly remain out of the west/northwest at around 5-10 knots with gusts up to 15-20 knots at times. Overnight fog and stratus looks to return again Monday night into Tuesday morning. OUTLOOK MONDAY NIGHT THROUGH THURSDAY NIGHT... Rain and thunderstorm chances end for Tuesday/Wednesday, with likely overnight fog and low stratus continuing to be an issue. Chances of SHRA/TSRA return Thursday and Friday with another cold frontal passage. Mainly VFR outside of any storms and late night BR/stratus. && .HYDROLOGY... FLOOD WATCH IN EFFECT THROUGH LATE MONDAY NIGHT FOR PARTS OF WV AND VA...... An active upper level pattern will combine with surface boundaries and adequate instability to produce several rounds of showers and storms through Monday night. A Flood Watch has been issued for parts of SE WV and along the WV/VA border where FFG values are less than 1.50 inches for 1 hour. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Flood Watch through late tonight for VAZ019-020. NC...None. WV...Flood Watch through late tonight for WVZ042>044-507-508. && $$ DISCUSSION...EB AVIATION...EB HYDROLOGY...SH