Sufficient atmospheric instability and moisture, allowed scattered showers and thunderstorms to develop and move across the region in the evening, some of which reached severe limits.
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 CAE wrote it up.
Sufficient atmospheric instability and moisture, allowed scattered showers and thunderstorms to develop and move across the region in the evening, some of which reached severe limits.
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 Columbia, SC wrote its last area forecast discussion before the first event at Jul 1, 6:18 PM EST, 8 minutes earlier.
Area Forecast Discussion National Weather Service Columbia SC 718 PM EDT Sat Jul 1 2017 .SYNOPSIS... High pressure will extend from the Atlantic westward through the northern Gulf of Mexico through Independence Day. North of the ridge some troughing will be in the forecast area. The pattern supports seasonal hot conditions with a chance of mainly afternoon and evening thunderstorms. && .NEAR TERM /UNTIL 7 AM SUNDAY MORNING/... Thunderstorms which developed in the Upstate and Piedmont have moved eastward into the northern Midlands and Catawba regions. Additional storms from NE GA will move eastward possibly entering the western Midlands this evening. Storms should weaken after sunset and then dissipate before midnight. Moderate potential instability and dry air aloft will pose a threat for damaging winds from thunderstorms in these areas. Elsewhere, isolated showers or thunderstorms can be expected. Cloud cover overnight from decayed convection will keep temperatures in the low to mid 70s. && .SHORT TERM /7 AM SUNDAY MORNING THROUGH TUESDAY/... Surface ridging will continue from the Atlantic westward through the northern Gulf of Mexico. North of the ridge, lee- side surface troughing will be in the forecast area. The region will be near the southern periphery of broad mid-level troughing with a series of shortwave troughs brushing the area. Convergence into the surface trough and strong heating plus upper lift at times supports thunderstorms. The models show some h5 shortwave ridging and h85 westerly flow Sunday. The NAM and GFS MOS have been consistent with low pops Sunday. The models have trended with more defined 5h shortwave troughing Monday and Tuesday. MOS pops have trended upward those days. The models indicate moderate instability each day with surface-based LI values around -7. A few of the thunderstorms may contain strong wind. Temperatures may be highest Sunday with less thunderstorm coverage. Followed the guidance consensus temperatures and forecasted highs mainly in the middle 90s Sunday, and lower 90s Monday and Tuesday. The MOS supports heat index values peaking near 100 each day. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... The GFS and ECMWF show surface ridging extending from the Atlantic westward into the northern Gulf of Mexico with lee-side troughing in the forecast area during much of the medium-range period. Broad upper trough is forecast to become more pronounced in the region during the period. The pattern supports scattered to numerous thunderstorms. Followed the guidance consensus and forecasted chance pops each day. The GFS and ECWMF MOS have near normal temperatures during the period. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... VFR conditions expected through most of the TAF period. Currently monitoring scattered convection mainly just north of the TAF sites along with other storm cells over NE GA. For now, given latest trends, will not mention any precipitation at any of the TAF sites but will monitor. Convection should diminish after sunset will loss of daytime heating. Overnight clouds will remain over the region with southwesterly winds around 5 mph. Have kept cigs VFR overnight due to winds and limited moisture in the near surface layer without rainfall. Winds will be southwesterly through 02/15z...then veer to westerly for the remainder of the period. EXTENDED AVIATION OUTLOOK...Restrictions possible in late night/early morning stratus/fog, along with scattered mainly afternoon/evening thunderstorms each day. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
Hazardous Weather Outlook National Weather Service Columbia SC 323 AM EDT Sat Jul 1 2017 GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-020730- Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield- McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington- Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon- Bamberg- 323 AM EDT Sat Jul 1 2017 This Hazardous Weather Outlook is for the Midlands of South Carolina and the Central Savannah River area of Georgia. .DAY ONE...Today and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Sunday through Friday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Columbia SC
607 PM EDT SAT JUL 1 2017
SCZ015-012245-
Lancaster-
607 PM EDT SAT JUL 1 2017
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN LANCASTER COUNTY...
At 607 PM EDT, a strong thunderstorm was located over Pineville, or
10 miles south of Uptown Charlotte, moving south at 15 mph.
Winds 30 to 40 mph are possible with this storm.
Locations impacted include...
Waxhaw.
LAT...LON 3493 8078 3482 8080 3482 8075 3478 8087
3483 8090 3484 8087 3490 8088 3493 8086
3496 8087 3501 8091 3503 8090 3507 8090
TIME...MOT...LOC 2207Z 338DEG 15KT 3508 8091
awpThe Columbia radar (KCAE), 104 km away, was scanning. The volume nearest the first event began at 23:26 UTC.
4 thunderstorm wind. Local standard time, as filed.
Lancaster County dispatch reported trees down blocking the roadway near the intersection of N Rocky River Rd and Camp Creek Rd.
Edgefield County Sheriffs Office reported trees and power lines down on Hwy 25.
A tree was downed on Interstate 26 westbound near mile marker 78.
Tree down at SC Hwy 34 and Ringer Rd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2017Every state in 2017This day in weather historyWarnings in South Carolina, July 2017
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 2026-10-01. Each event’s entry at NCEI: 698177, 698178, 698180, 698181.