Scattered showers and t'storms developed on August 18th producing some heavy downpours at times. These heavy downpours led to isolated flooding reports.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS OHX wrote it up.
Scattered showers and t'storms developed on August 18th producing some heavy downpours at times. These heavy downpours led to isolated flooding reports.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Nashville, TN wrote its last area forecast discussion before the first event at Aug 18, 5:37 AM CST, 5 hours earlier.
Area Forecast Discussion National Weather Service Nashville TN 637 AM CDT Wed Aug 18 2021 .UPDATE... FOR 12Z AVIATION DISCUSSION. && .DISCUSSION... After bringing some light rain to our Plateau counties yesterday, Tropical Depression Fred has scooted off to the northeast leaving us a quiet radar scope this morning. Some patchy fog is noted on a few surface obs this hour, especially over our eastern counties which saw rain yesterday, and cannot rule out some locally dense fog through sunrise. Otherwise, today looks to be a tad warmer than yesterday with highs reaching the mid 80s on the Plateau and upper 80s to around 90 elsewhere. However, high pops return by afternoon as a surge of deeper moisture characterized by precipitable water values over 2 inches moves in from the southwest. In fact, regional radar imagery already shows some scattered showers and storms around the Memphis area along the leading edge of this moisture surge. Numerous showers and thunderstorms are likely to develop this afternoon across West Tennessee and our western counties, then spread eastward across the rest of our forecast area through the evening hours before diminishing. Although forecast soundings don't show anything to write home about for today, deep layer shear increasing up to 30 knots along with the high PWAT values could allow for a few storms with damaging wet microbursts. Locally heavy rain and maybe some isolated flooding is also possible later today, but forecast storm motions up to 25 mph should limit any flood issues. Localized flooding appears to be more of a concern after midnight tonight into Thursday morning as model guidance all develop another complex of fairly heavy showers and storms which moves through the cwa. Once again, cannot rule out a few strong storms with this second complex late tonight into the day on Thursday, but threat is low. The widespread rain early Thursday should keep temperatures down quite a bit with highs only in the upper 70s to mid 80s. Two more wet days are expected Friday and Saturday as the airmass remains very moist (PWATs around 2.25 inches) with scattered to numerous showers and storms each day. Global models have been very consistent in showing yet another complex of storms affecting at least the western half of the area Saturday morning as a substantial shortwave trough moves across within the northwest flow aloft. By Sunday, 00Z GFS/ECMWF strengthen a large H5 ridge over the lower Mississippi Valley that shifts westward into the Southern Plains early next week, with our neck of the woods on the eastern side of this upper ridge. This development in the upper pattern should squash our precip chances back down to slight/low chance, as well as allow our temperatures to heat back up into the 90s west of the Plateau. By late week, however, the global models also suggest that the ridge will break down with our wet August weather making a return. && .AVIATION... 12Z TAF DISCUSSION. BNA/MQY/CKV/CSV...We start the day with VLIFR conditions at CSV, which should improve considerably by 13Z. Already an area of mainly light showers is drifting across West Tennessee and will cross the Tennessee River shortly, but the HRRR suggests that this batch of rain will dissipate rather quickly. Stronger cells will develop over West Tennessee this afternoon and will spread into Middle Tennessee, so we'll handle this with TEMPO TSRA/CB's for now. A shortwave approaching Middle Tennessee from the west looks to intensify as it enters the mid state overnight, so look for another round of showers and low ceilings after 06Z. Winds will stay generally light/calm thru the TAF period. && .OHX WATCHES/WARNINGS/ADVISORIES... NONE. && DISCUSSION......Shamburger AVIATION........08
Hazardous Weather Outlook National Weather Service Nashville TN 716 AM CDT Wed Aug 18 2021 TNZ005>011-023>034-056>066-075-077>080-093>095-191030- Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston- Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-Jackson- Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-Maury- Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-Coffee- Warren-Grundy-Van Buren-Wayne-Lawrence-Giles- 716 AM CDT Wed Aug 18 2021 This Hazardous Weather Outlook is for Middle Tennessee. .DAY ONE...Today and tonight. There is a marginal risk of severe storms today, particularly during the afternoon. The primary risk is strong to severe wind gusts. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. There is a high probability of showers and thunderstorms lasting through Saturday night. Significant rainfall accumulations are possible in areas that are affected by multiple rounds of storms, and some flooding may occur, especially in areas near the Alabama state line. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. Please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. 12
The Nashville radar (KOHX), 12 km away, was scanning. The volume nearest the first event began at 16:36 UTC.
3 flash flood, 1 lightning. Local standard time, as filed.
Two adults were reportedly struck by lightning at Hickman Elementary School on Stewarts Ferry Pike, but only suffered minor injuries.
Flooding on streets across Vandy Campus including 24th Avenue South and outside of the 25th South Avenue garage.
Several roads were flooded in the Capitol View, Music Row, and Midtown areas of Nashville including West End Avenue, Chet Atkins Place, 10th Avenue North, Nelson Merry Street, and Exit 1 on I-440 West. Streets were also flooded across the Vanderbilt University campus, including 24th Avenue South and 25th Avenue South outside the parking garage.
Several roads were flooded across the county including Doolittle Road, Sunny Slope Road at Hollis Creek, and Highway 145. A water rescue was conducted for a vehicle that hydroplaned into a flooded ditch on Lassiter Barker Road at John Bragg Highway.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2021Every state in 2021This day in weather historyWarnings in Tennessee, August 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 978821, 978822, 978823, 978824.