Slow moving showers and thunderstorms developed along the southern periphery of a wedge boundary or slowly lifting warm front, resulting in heavy rainfall and flash flooding along with small hail in northern Lancaster County.
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.
Slow moving showers and thunderstorms developed along the southern periphery of a wedge boundary or slowly lifting warm front, resulting in heavy rainfall and flash flooding along with small hail in northern Lancaster County.
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 Apr 30, 6:51 PM EST, 1 hour 4 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 751 PM EDT SAT APR 30 2016 .SYNOPSIS... A STATIONARY FRONT NEAR THE NORTH AND SOUTH CAROLINA BORDER WILL LIFT NORTH AS A WARM FRONT TONIGHT. A MOIST SOUTHERLY FLOW WILL OCCUR OVER THE FORECAST AREA THROUGH SUNDAY. A SLOW MOVING COLD FRONT WILL MOVE NEAR THE REGION MONDAY. AN AREA OF LOW PRESSURE WILL LIKELY DEVELOP ALONG THE FRONT NEAR THE FORECAST AREA TUESDAY. && .NEAR TERM /UNTIL 8 AM SUNDAY MORNING/... UPPER RIDGE NEAR THE US EAST COAST...WITH UPPER TROUGHINESS TO OUR WEST. A SURFACE HIGH PRESSURE WEDGE IS IN PLACE ACROSS THE MID ATLANTIC AND OVER MUCH OF NC...WITH THE WEDGE BOUNDARY ACROSS SRN NC. THE WEDGE BOUNDARY/WARM FRONT IS PROGGED TO CONTINUE LIFTING SLOWLY NORTH. A NORTH TO SOUTH LOW LEVEL CONVERGENCE BOUNDARY CURRENTLY STRETCHES ACROSS GA...WEST OF OUR FORECAST AREA (FA)...WHERE SCT SHOWERS/TSTMS IN PROGRESS. OTHER CONVECTIVE ACTIVITY OVER UPSTATE SC...WITH SOME ADDITIONAL ACTIVITY NEAR THE NE MIDLANDS NEAR THE WARM FRONT. ALL ACTIVITY IS SHIFTING TO THE NE. IN THE NEAR TERM...WILL EXPECT CHANCE POPS NEAR THE CSRA AND NEAR THE NORTHERN MIDLANDS. THIS EVENING...EXPECTING A GENERAL DECLINE IN THE ACTIVITY WITH THE LOSS OF HEATING. LATER TONIGHT...A WEAK UPPER DISTURBANCE IS PROGGED TO ROLL THROUGH LATE TONIGHT. LATEST HIGH RESOLUTION MODELS SUGGEST CHANCE TO SLIGHT CHANCE POPS IN ORDER. && .SHORT TERM /8 AM SUNDAY MORNING THROUGH TUESDAY/... .SUNDAY...SUNDAY WILL BE CHARACTERIZED BY CONSIDERABLE CLOUDINESS ONCE AGAIN WITH PWS IN THE 1.5 INCH RANGE AND CONTINUED UPPER LEVEL MOISTURE TRANSPORT FROM THE WEST AND SOUTHWEST. THERE REMAINS SIGNIFICANT SPREAD IN THE GUIDANCE IN TERMS OF POPS/QPF/TIMING...SO I LEANED MORE ON THE PROXIMITY TO THE UPPER LEVEL JET MORE THAN ANYTHING ELSE WITH LITTLE IN THE WAY OF FOCUSING SURFACE CONVERGENCE ON THE SYNOPTIC SCALE. THEREFORE...POPS ARE HIGHEST IN THE NORTHWESTERN PORTION OF THE CWA...CLOSER TO THE AGEOSTROPHIC LIFT BEING INDUCED BY UPPER DIVERGENCE NEAR A JET STREAK THAT SHOULD PASS OVER TENNESSEE DURING THE DAY. DUE TO THE CLOUD COVER...TEMPS WILL BE A TOUCH COOLER THAN NORMAL IN THE AFTERNOON...RANGING FROM NEAR 80 NEAR THE NC BORDER TO THE MID 80S IN THE CSRA. .SUNDAY NIGHT...NOT MUCH CHANGE IN THE PATTERN. THE STRONGEST MID TO UPPER LEVEL FLOW WILL REMAIN NORTH OF THE AREA...BUT SMALL DISTURBANCES IN THE FLOW WILL ALLOW FOR THE CHANCE OF SOME SHOWERS...AND MAYBE A THUNDERSTORM IN THE EVENING. OVERNIGHT TEMPS WILL BE ABOVE NORMAL...IN THE MID TO UPPER 60S...AS CONSIDERABLE CLOUDINESS AND PERSISTENT LOW LEVEL SOUTHERLY FLOW WILL RETARD THE USUAL DIURNAL TEMPERATURE DROP OVERNIGHT. .MONDAY...MID LEVEL HEIGHTS FALL JUST A LITTLE BIT ON MONDAY...BUT THE MAIN JET ENERGY WILL SPEND YET ANOTHER DAY NORTH OF THE CWA OVER THE OHIO VALLEY. SURFACE FRONT WILL REMAIN TO THE NORTH AS WELL...AND WITH UPPER LEVEL MOISTURE DECREASING A BIT WE MAY GET SOME MORE SUNSHINE AND SEE TEMPS CREEP BACK UP TO THE MID 80S EVERYWHERE. THE WARMER SURFACE TEMPS AND THE SLIGHT DIP IN HEIGHTS ALOFT WILL LOAD TO A LITTLE BETTER AFTERNOON INSTABILITY...HOWEVER...SO THE CHANCE OF THUNDERSTORMS WILL REMAIN IN THE FORECAST. THIS TIME AROUND...THE CHANCES MAY BE A LITTLE BETTER OVER THE SOUTHERN HALF OF THE FA WHERE THE INSTABILITY BECOMES THE GREATEST. .MONDAY NIGHT...HEIGHTS WILL LOWER FURTHER MONDAY NIGHT AS THE FIRST SIGNS OF A DEVELOPING DEEP TROF/UPPER LOW BEGIN TO APPEAR. THIS WILL SUPPORT THE MAINTENANCE OF CONVECTION THAT DEVELOPS DURING THE AFTERNOON WELL INTO THE EVENING HOURS...WITH AGAIN A CHANCE OF THUNDERSTORMS EVERYWHERE. THE ACTIVITY SHOULD GRADUALLY WIND DOWN OVERNIGHT WITH THE LOSS OF INSTABILITY...BUT IT COULD LINGER FOR A WHILE IN THE NORTHERN HALF OF THE CWA WITH MORE UPPER JET SUPPORT. .TUESDAY...THIS SHOULD BE THE MOST LIKELY DAY FOR RAIN ACROSS THE CWA. THE ONLY REAL QUESTION IS TIMING AND PLACEMENT. THE GFS IS FASTER WITH THE UPPER FLOW AND HAS MOST OF THE RAIN IN THE SOUTHEASTERN HALF OF THE CWA...WHILE THE ECMWF IS SLOWER AS IT HAS A DEEPER DISTURBANCE DEVELOPING...PUTTING THE ENTIRE CWA IN THE CROSSHAIRS OF THE BETS RAIN CHANCES. FOR NOW...DUE TO THE UNCERTAINTY...I TOOK A MODEL BLEND APPROACH...BUT IT WOULD NOT SURPRISE ME TO SEE AN INCREASE TO LIKELY POPS MOST AREAS ON TUESDAY IF CURRENT TRENDS CONTINUE. ONCE AGAIN...CLOUD COVER WILL KEEP MAX TEMPS DOWN A LITTLE BELOW NORMAL. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... THERE IS A DECENT AMOUNT OF UNCERTAINTY DURING THE MIDDLE OF THE WEEK DUE TO SIGNIFICANT DIFFERENCES. FOR EXAMPLE...COMPARING THE 12Z RUNS OF THE ECMWF AND GFS...THE EC HAS A MUCH SHARPER TROF OVER NORTHERN GEORGIA...STARTING TO GO NEGATIVE TILT...WHILE THE GFS HAS A MUCH MORE ROUNDED SHAPE...IMPLYING MUCH LESS SYNOPTIC SUPPORT FOR CONVECTION. THEREFORE...THE GFS IS MUCH DRIER THAN THE EC FOR WEDNESDAY. THE AGREEMENT GETS A LITTLE BETTER AT MID LEVELS FOR THURSDAY AS THEY BOTH SHOW AN ANOMALOUS UPPER LOW DEVELOPING IN THE NORTHEASTERN QUARTER OF THE COUNTRY...BUT THE SURFACE DETAILS ARE DIVERSE WITH THE GFS SHOWING A MUCH WEAKER SURFACE LOW. THEY BOTH HINT AT A FEW SHOWERS POSSIBLE IN THE AFTERNOON UNDER THE CYCLONIC FLOW ALOFT...SO I HAVE SLIGHT CHANCE TO LOW END CHANCE POPS IN FOR MOST OF THE CWA ON THURSDAY. FRIDAY BOTH MODELS SHOW SOME VERY UNSEASONABLY COOL TEMPS ON THE BACK SIDE OF THE UPPER LOW....MODIFYING ONLY A LITTLE BY SATURDAY. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... EVENING CONVECTION SHOULD REMAIN NORTH AND WEST OF THE TAF SITES. SOME MODEL GUIDANCE SUGGESTING SOME OVERNIGHT SHOWERS ASSOCIATED WITH A PASSING UPPER DISTURBANCE BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE FORECAST. BUT THERE IS A POSSIBILITY OF SOME OVERNIGHT SHOWERS DURING THE 04Z-12Z TIME FRAME. REASONABLE CONFIDENCE THAT LOW STRATUS WILL DEVELOP AGAIN TONIGHT WITH A 30-35 KNOT LOW LEVEL JET. WILL CONTINUE MVFR/IFR CIGS DEVELOPING 03Z-06Z AND LINGERING THROUGH 14Z-15Z. SCATTERED CONVECTION EXPECTED TO DEVELOP DURING THE AFTERNOON IN MOIST AND UNSTABLE AIR MASS WITH POSSIBLY A WEAK UPPER LEVEL DISTURBANCE CROSSING THE REGION. SOUTHEAST WINDS 5 TO 10 KNOTS OVERNIGHT WILL BECOME SOUTHWEST AROUND 10 KNOTS SUNDAY MORNING. EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS ARE POSSIBLE FOR A FEW HOURS AT THE TERMINALS MONDAY THROUGH WEDNESDAY MORNINGS AS THE LOW LEVEL MOISTURE REMAINS ACROSS THE AREA. OTHERWISE...SCATTERED CONVECTION MAY CAUSE SOME BRIEF MVFR/IFR CONDITIONS EACH AFTERNOON/EVENING THROUGH WEDNESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE COLUMBIA SC 317 PM EDT SAT APR 30 2016 GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-011930- LINCOLN-MCDUFFIE-COLUMBIA-RICHMOND-BURKE-LANCASTER-CHESTERFIELD- MCCORMICK-NEWBERRY-FAIRFIELD-KERSHAW-EDGEFIELD-SALUDA-LEXINGTON- RICHLAND-LEE-AIKEN-SUMTER-BARNWELL-ORANGEBURG-CALHOUN-CLARENDON- BAMBERG- 317 PM EDT SAT APR 30 2016 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MIDLANDS OF SOUTH CAROLINA AND THE CENTRAL SAVANNAH RIVER AREA OF GEORGIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE COLUMBIA SC
715 PM EDT SAT APR 30 2016
SCZ015-010000-
LANCASTER-
715 PM EDT SAT APR 30 2016
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN LANCASTER COUNTY...
AT 715 PM EDT...A STRONG THUNDERSTORM WAS NEAR LESSLIE...OR 8 MILES
SOUTHEAST OF ROCK HILL...MOVING NORTH AT 35 MPH.
WIND GUSTS OF 35 TO 45 MPH ARE POSSIBLE WITH THIS STORM.
LOCATIONS IMPACTED INCLUDE...
WAXHAW.
TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.
LAT...LON 3493 8078 3482 8080 3482 8075 3479 8078
3482 8090 3484 8087 3490 8088 3493 8086
3496 8087 3501 8091 3503 8090 3505 8091
3507 8090
TIME...MOT...LOC 2315Z 195DEG 32KT 3488 8090
LMThe Columbia radar (KCAE), 114 km away, was scanning. The volume nearest the first event began at 00:53 UTC.
2 flash flood, 1 hail. Local standard time, as filed.
Lancaster County Dispatch reported flooding at Collins Rd and Hwy 521. The road was impassable.
SKYWARN Spotter reported nickel sized hail on Whimbrel Circle.
Man O War Drive was flooded and appeared impassable based on video posted on social media by broadcast media. Department of Highways also reported Straightaway Lane at Black Horse Run Road flooded with about 6 inches of water on the roadway.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2016Every state in 2016This day in weather historyWarnings in South Carolina, April 2016
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 2026-09-30. Each event’s entry at NCEI: 622447, 622450, 622449.