A strong cold front and prefrontal trough tracking from the Ohio and Tennessee River Valleys dove southeast into our region Saturday afternoon. 7 inches.
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 RNK wrote it up.
A strong cold front and prefrontal trough tracking from the Ohio and Tennessee River Valleys dove southeast into our region Saturday afternoon. These two features triggered numerous showers and storms that feed off of CAPE values greater than 1,500 j/kg and PWATs that approach 1.5 to 1.7 inches. The storm mode started as multicellular clusters then transitioned into organized line segments as deep layer shear strengthened. This promoted areas of wind damage along with instances of large hail and localized flash flooding during the afternoon and evening.
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 Blacksburg, VA wrote its last area forecast discussion before the first event at Jul 17, 4:50 AM EST, 6 hours 41 minutes earlier.
Area Forecast Discussion National Weather Service Blacksburg VA 550 AM EDT Sat Jul 17 2021 .SYNOPSIS... A cold front approaches the area today with more numerous showers and thunderstorms. A second front passes through the area Wednesday and Thursday. The passage of this front will introduce slightly cooler temperatures, and lower humidity. && .NEAR TERM /THROUGH TONIGHT/... As 355 AM EDT Saturday... Showers and thunderstorms expected today into tonight. An upper level trough over the East will deepen today into tonight. A strong shortwave will rotate around the upper trough and move across the Appalachians this afternoon into tonight. As the trough sharpens, our region is in an area of upper diffluence this afternoon. A cold front and a prefrontal trof will travel southeast today into tonight. Scattered showers and thunderstorms will develop today with the best chances during the afternoon into this evening. PWATS increase from an 1.25 inch to nearly two inches so some of the storms could contain heavy rains. Moderate to strong instability will develop with heating resulting in the potential for a few strong to severe thunderstorms. The main threats will be gusty winds and heavy rains. Deep layer shear does increase a little today with CAPEs climbing to around 1500 j/KG. The day one convective outlook place eastern areas in a marginal risk for severe weather. High temperatures will range from the mid 70s in the mountains to the lower 90s in the Piedmont. The cold front will drop southeast into the western slopes of the Appalachian mountains tonight. Before this happens, strong prefrontal convection will move east of the Blue Ridge this evening and may linger tonight especially over the piedmont. The intensity of this convection and rainfall will decrease around midnight, but light showers may persist overnight into Sunday morning as a shortwave trough moves east over the region. Areas of fog will develop tonight into Sunday morning. Low temperatures overnight will vary from around 60 degrees in the mountains to near 70 in the piedmont. Moderate confidence in the Near Term Forecast. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 400 AM EDT Saturday... A slow moving west-east oriented cold front will sag southward toward the VA/NC border by afternoon. Broad upper troughing will remain over the eastern U.S. Scattered showers and isolated thunderstorms will remain possible in the morning along/near the frontal boundary. Daytime heating will be confined mainly to the piedmont and Southside VA by afternoon, which where the strongest thunderstorms would be expected. Currently SPC only shows general thunder, but notes in the SWODY2 discussion that an isolated damaging wind gust cannot be ruled out on a mesoscale basis. The greater threat for severe and flooding rainfall continues to be Saturday afternoon, not Sunday. However, locally heavy rainfall will remain possible Sunday afternoon, especially across the NW NC mountains and into the NC piedmont and foothills and as far northeast as Danville and South Boston. Cloud cover and precipitation will hold temperatures down to below normal levels, especially in the west and north Sunday. Highs will be mostly in the 70s, with even 60s in the mountains. Lows will be mostly in the 60s. 80s are expected across the piedmont before the precipitation reaches/develops in those areas Sunday afternoon. Monday, the front will sag very slowly southward toward the I-40 corridor. How far south the front moves before stalling and how quickly that occurs remain big questions for the extended forecast. Confidence is only moderate with respect to the frontal boundary moving toward the I-40 corridor by Monday morning. The GFS continues to be on the fast end of the spectrum in moving the front south, while the ECMWF remains on the slow end. Have tapered pops from likely far south to slight chance far north. Areas along/north of the I-64 corridor could very well remain totally dry Monday, despite the NBMs high chance pops in those areas which seem unrealistic per any model. On the other hand NC counties, and especially the NW NC mountains will likely see another day of scattered to numerous showers/thunderstorms. Temperatures will remain below normal across the entire area, but should recover a bit closer to normal across the northern areas where there will be more sunshine and heating. There won't be enough drying of the air mass for dewpoints to drop below 60, so nights will still be mild to muggy. /Confidence Levels in Forecast Parameters/ - Moderate to High Confidence in Temperatures, - Moderate Confidence in Probabilities of Precipitation, - High Confidence in Wind Direction and Speed, - Moderate Confidence in Thunderstorm Potential. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 415 AM EDT Saturday... Little change expected in the synoptic pattern. Broad upper troughing will persist across the eastern U.S. with the early week frontal system stalling across the southeastern U.S., but remaining close enough to potentially tease the southern parts of the CWA with deeper moisture and possibly a few showers/thunderstorms during afternoon heating. By Wednesday, another frontal system will drop southward from the Great Lakes into the Mid-Atlantic and Ohio Valley. Moisture will be more limited with this system than with the early week frontal system, but given mid-July strong heating, reasonably abundant moisture, and upper troughing/short wave energy, expect scattered showers/thunderstorms to develop during this time frame and drift southward. NBM pops are too low for this scenario so have raised them at least into the 20-30 percent range and coordinated with neighboring offices for such. This front will also linger across NC into TN during the later half of the week and keep a threat of showers/isolated thunderstorms in those areas all week, less so further north. Another frontal system approaches in a similar manner by the weekend. As the upper troughing cuts off in the south central U.S. and the general flow across the Mid-Atlantic region becomes more zonal, warm air and deeper moisture will creep back northward during the later half of the week allowing temperatures to warm back well into the 80s with 70s mountains and muggy overnight lows in the 60s to lower/mid 70s locations such as ROA. Chances for showers/thunderstorms will also be on the increase across the entire region by the end of the week. /Confidence Levels in Forecast Parameters/ - Moderate to High Confidence in Temperatures, - Low to Moderate Confidence in Probabilities of Precipitation, - Moderate Confidence in Wind Direction and Speed, - Moderate Confidence in Thunderstorm Potential. && .AVIATION /10Z SATURDAY THROUGH WEDNESDAY/... As of 550 AM EDT Saturday... MVFR to IFR fog will develop in the western river valleys this morning but may be hinder by cloud cover. Showers and a few storms have already developed in the western mountains. Clouds from this convection are hindering fog this morning at KLWB. Any morning fog and low clouds should lift or dissipate by late morning. Numerous Sub-VFR showers and thunderstorms will develop especially this afternoon. The highest probability of precipitation will be across the mountains. Confidence is high enough to bring showers with VCTS at ROA/BCB in the afternoon, with less in the east so leaving VCTS at LYH/DAN. when it rains expect MVFR to IFR cigs/vsbys. Winds will be erratic and gusty near thunderstorms this afternoon into this evening. Areas of fog and low clouds will develop late tonight into Sunday morning especially where it rained. Above average confidence for ceiling, visibility and wind. Extended Aviation Discussion... Showers/storms will continue into Sunday with sub- VFR ceilings and visibilities. By Tuesday the boundary will be south of the region with cooler and drier weather and a return to widespread VFR conditions. Scattered MVFR storms are possible Wednesday and Thursday. Some drier air will arrive for Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && SYNOPSIS...AMS/KK NEAR TERM...KK SHORT TERM...RAB LONG TERM...RAB AVIATION...KK/WP
Hazardous Weather Outlook National Weather Service Blacksburg VA 449 AM EDT Sat Jul 17 2021 NCZ001>003-018>020-VAZ007-009>017-WVZ042-181100- Ashe-Alleghany NC-Surry-Watauga-Wilkes-Yadkin-Tazewell-Smyth-Bland- Giles-Wythe-Pulaski-Montgomery-Grayson-Carroll-Floyd-Mercer- 449 AM EDT Sat Jul 17 2021 This Hazardous Weather Outlook is for north central North Carolina, northwest North Carolina, southwest Virginia and southeast West Virginia. .DAY ONE...Today and tonight. Scattered to numerous showers and thunderstorms are expected today and tonight. A strong to severe thunderstorm with damaging winds gusts cannot be ruled out. In addition, locally heavy rainfall leading to localized flooding or flash flooding will be possible, especially along and west of the Blue Ridge. .DAYS TWO THROUGH SEVEN...Sunday through Friday. There is a low probability for widespread hazardous weather. .SPOTTER INFORMATION STATEMENT... Limited spotter activation is possible today and tonight, mainly this afternoon and evening, for isolated severe storms and a few incidents of flooding or flash flooding. NCZ004>006-VAZ018>020-022>024-032>035-043>047-058-059-WVZ043-044-507- 508-181100- Stokes-Rockingham-Caswell-Craig-Alleghany VA-Bath-Roanoke-Botetourt- Rockbridge-Patrick-Franklin-Bedford-Amherst-Henry-Pittsylvania- Campbell-Appomattox-Buckingham-Halifax-Charlotte-Summers-Monroe- Eastern Greenbrier-Western Greenbrier- 449 AM EDT Sat Jul 17 2021 This Hazardous Weather Outlook is for north central North Carolina, central Virginia, south central Virginia, southwest Virginia, west central Virginia and southeast West Virginia. .DAY ONE...Today and tonight. Scattered to numerous showers and thunderstorms are expected today and tonight. A few storms could become strong to severe, mainly this afternoon and evening. In addition, locally heavy rainfall leading to localized flooding or flash flooding will be possible. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Scattered showers and thunderstorms will be possible again Monday, mainly near and south of the Virginia/North Carolina border. The main concern with these storms will be localized pockets of heavy rainfall and associated flooding. There is a low probability for widespread hazardous weather. .SPOTTER INFORMATION STATEMENT... Limited spotter activation is possible today, tonight, and again Sunday, mainly during the afternoon and evening, for a few severe storms and a possible incidents of flooding or flash flooding. RAB
Special Weather Statement
National Weather Service BLACKSBURG VA
1201 PM EDT Sat Jul 17 2021
VAZ033-034-043-044-171630-
Henry-Franklin-Bedford-Pittsylvania-
1201 PM EDT Sat Jul 17 2021
...A STRONG THUNDERSTORM WILL AFFECT NORTHERN PITTSYLVANIA...
SOUTHWESTERN BEDFORD...NORTHERN HENRY AND FRANKLIN COUNTIES...
At 1200 PM EDT, a strong thunderstorm was located over Ferrum, moving
northeast at 20 mph.
Winds in excess of 30 mph are possible with this storm.
Locations impacted include...
Bedford...
Rocky Mount...
Gretna...
Huddleston...
Ferrum...
Moneta...
and Penhook.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
If you are on or near Smith Mountain Lake get out of the water and
move indoors or inside a vehicle. Remember, lightning can strike out
to 10 miles from the parent thunderstorm. If you can hear thunder,
you are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.
LAT...LON 3688 7919 3677 8003 3683 8008 3684 8007
3684 8010 3694 8019 3696 8017 3695 8014
3700 8013 3736 7953 3715 7938 3706 7944
3706 7940 3709 7940 3711 7937 3712 7938
3712 7936
TIME...MOT...LOC 1600Z 246DEG 16KT 3690 7997
ASThe Roanoke radar (KFCX), 32 km away, was scanning. The volume nearest the first event began at 16:28 UTC.
7 thunderstorm wind, 1 lightning, 1 hail. Local standard time, as filed.
One tree was reported blown down due to thunderstorm winds five miles south-southwest of Rocky Mount, Virginia. Power lines were also reported down due to downed tree branches from the same storm along Ruritan Road.
A house was struck by lightning in the community of Laurel Fork, VA.
One tree blown down due to thunderstorm winds along Village Highway. One tree was also blown down by the same storm three miles southwest of Concord, Virginia.
Two trees were blown down due to thunderstorm winds.
A small metal shed was blown across Mt. Laurel Road due to thunderstorm winds. Siding damage to a home was also reported.
Two trees blown down by thunderstorm winds at the intersection of While Rock Road and West Midland Trail.
Multiple trees blown down due to thunderstorm winds at the intersection of South River Road and Nature Camp Road.
One tree was blown down due to thunderstorm winds along Fisher Farm Road. Law enforcement also reports a large tree branch blown down in the same area bringing down power lines.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2021Every state in 2021This day in weather historyWarnings in Virginia, July 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: 973076, 973077, 973082, 973083, 973180, 973181, 973182, 973183, 973184.