A large area of thunderstorms developed upstream of the region in the mid afternoon hours. These thunderstorms progressed across much of southeast South Carolina through the evening and damaging wind gusts.
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 CHS wrote it up.
A large area of thunderstorms developed upstream of the region in the mid afternoon hours. These thunderstorms progressed across much of southeast South Carolina through the evening and damaging wind gusts.
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 Charleston, SC wrote its last area forecast discussion before the first event at May 3, 3:26 PM EST, 1 hour 20 minutes earlier.
Area Forecast Discussion National Weather Service Charleston SC 426 PM EDT Mon May 3 2021 .SYNOPSIS... High pressure will extend across the region through tonight. A series of upper level disturbances could bring unsettled weather through mid week before a cold front crosses the region late Wednesday into Thursday. Dry high pressure is then expected to prevail through next weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... The larger-scale, synoptic features include surface high pressure over the Atlantic and a broad upper trough over much of the Western and Central US. Within the larger scale trough, is an embedded shortwave located over the Eastern Tennessee Valley, which is expected to lift northeast through the night. The main concern for the early portion of the night will be to watch for any upstream convection drifting into the forecast area during the late evening hours. Analyzing several severe parameters, the environment is primed for convection; bulk shear is expected to decrease to a rather modest 30 kt by early evening which decreases the potential for moderate cell organization. Instability (CAPE) is currently around 2500 J/kg across the northwest portions of the forecast area, decreasing to 750-1000 J/kg well after sunset. Isolated strong to severe thunderstorms are possible with the primary hazards being damaging wind gusts and hail. The most likely time frame for potential severe is between 6PM and 11PM, targeting our inland counties: Berkeley, Dorchester, Colleton, Allendale, Screven, Jenkins, and Candler. These areas are more under the influence of the embedded shortwave energy aloft, as well as some weak low level convergence with the inland advancement of the seabreeze. SPC has our west and northwestern counties in a slight risk for severe weather through tonight, with areas to the south in a marginal risk and extreme southeastern Georgia in general thunder. The severe potential drastically diminishes toward the south and east, as the greatest forcing mechanisms are located over the Midlands. The majority of models show storms weakening downstream, with some solutions showing showers/thunderstorms diminishing shortly after entering our forecast area from the west. After midnight, we are expecting virtually no precipitation as nocturnal destabilization kicks in and the upper disturbance lifts well to our north. A warm pattern will continue overnight with much of the region dipping to the upper 60s/low 70s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday and Tuesday Night: An upper level shortwave will pass to our west, however it may produce enough forcing for scattered showers and thunderstorms to develop over the inland counties Tuesday afternoon. CAPE values 500 - 1000 J/kg indicate that thunderstorms are also possible. Tuesday's temperatures will be above average, with highs in the mid 80s to around 90 in some locations. Overnight low temperatures will be rather mild, with lows around 70. Wednesday and Wednesday Night: Another upper level shortwave embedded in the zonal flow aloft will produce the chance for some showers and thunderstorms to develop Wednesday afternoon. Models are showing that the precipitation associated with the cold front is not able to make it to the coast. Similar to many other instances this spring, a convective structure is forecasted to form over the Florida panhandle, cutting off moisture transport and essentially starving our area of any moisture which would support shower/storm development. Any showers/thunderstorms that are able to develop will most likely be limited to the far southern inland GA counties. POPs Wednesday afternoon have been adjusted down. Temperatures Wednesday will be above average again, with highs topping out in the mid to upper 80s. Overnight temperatures will reach into the low to mid 60s. Thursday: A 500mb trough is forecasted to swing through the southeastern states Thursday afternoon, bringing yet another chance for showers and thunderstorms. However, precipitation chances Thursday are uncertain at this point. Models are not in agreement, with some bringing in precipitation in the morning/early afternoon, while others are dry. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... After an upper level trough swings out over the eastern CONUS Thursday and into Friday, zonal flow aloft is expected through Monday. The next rain chances are Monday, however models are beginning to back off on the precipitation chances and POPs have been reduced from the last forecast. Temperatures are expected to return to closer to average, with highs generally in the upper 70s to around 80 and overnight lows in the mid to upper 50s. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... VFR with breezy afternoon gusts near 20 knots are expected. A shower or thunderstorm could develop in the evening hours or move in from upstream areas, but confidence is too low to include at this time. Extended Aviation Outlook: Prevailing VFR. There is a chance for brief flight restrictions with any showers/thunderstorms Tuesday/Wednesday afternoon. Friday afternoon could see gusty northwesterly winds. && .MARINE... Tonight: South to southwest flow will prevail across the local waters through the overnight period. The winds over the Charleston Harbor are expected to gust 22-25 kt, but should be short- lived, thus a Small Craft Advisory will not be issued as of now. Seas are expected to average 2-4 feet across the waters. Several upper level disturbances will produce periodic elevated winds and seas. Both Tuesday and Wednesday afternoons there is a chance for some gusty southwesterly winds over the waters, however no values reach Small Craft Advisory criteria. Seas generally 2 to 3 feet, with 4 feet possible in the far offshore waters Tuesday and Wednesday. Winds Thursday are expected to be northerly around 10 knots with seas 2 to 3 feet. Friday the next upper level disturbance makes its way across the region, bringing elevated winds. Wind gusts Friday 15 to 20 knots with seas 2 to 3 feet. Friday night and beyond winds around 10 knots and seas around 2 feet are expected. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && NEAR TERM...BRM SHORT TERM...CPM LONG TERM...CPM AVIATION...BRM/CPM MARINE...BRM/CPM
Hazardous Weather Outlook National Weather Service Charleston SC 138 PM EDT Mon May 3 2021 AMZ350-352-354-374-GAZ101-114>119-137>141-SCZ047>049-051-041745- Waters from South Santee River to Edisto Beach SC out 20 NM- Waters from Edisto Beach SC to Savannah GA out 20 NM- Waters from Savannah GA to Altamaha Sound GA out 20 NM, including Grays Reef National Marine Sanctuary- Waters from Savannah GA to Altamaha Sound GA from 20 to 60 NM- Effingham-Tattnall-Evans-Inland Bryan-Coastal Bryan-Inland Chatham- Coastal Chatham-Long-Inland Liberty-Coastal Liberty-Inland McIntosh- Coastal McIntosh-Inland Jasper-Beaufort-Coastal Colleton- Coastal Jasper- 138 PM EDT Mon May 3 2021 This Hazardous Weather Outlook is for Atlantic coastal waters, southeast Georgia and southeast South Carolina. .DAY ONE...This afternoon and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter assistance is not anticipated at this time. AMZ330-GAZ087-088-099-100-SCZ040-042>045-050-052-041745- Charleston Harbor-Jenkins-Screven-Candler-Bulloch-Allendale-Hampton- Inland Colleton-Dorchester-Inland Berkeley-Charleston-Tidal Berkeley- 138 PM EDT Mon May 3 2021 This Hazardous Weather Outlook is for Atlantic coastal waters, southeast Georgia and southeast South Carolina. .DAY ONE...This afternoon and tonight. Severe Thunderstorms: Isolated strong to severe thunderstorms are possible this evening into tonight with the primary hazards being damaging wind gusts and hail. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter assistance is not anticipated at this time.
The Charleston,SC radar (KCLX), 70 km away, was scanning. The volume nearest the first event began at 21:43 UTC.
5 thunderstorm wind. Local standard time, as filed.
Allendale County dispatch reported a tree down on Highway 125 near Millett Road.
Allendale County dispatch reported numerous trees down along Highway 125 and Highway 321.
A tree was reported down on Augusta Highway near Drain Road.
Dorchester County dispatch reported a tree down near Westburry Road and Wire Road.
Berkeley County dispatch reported a tree down on Highway 402 near Rectory Hill Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2021Every state in 2021This day in weather historyWarnings in South Carolina, May 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: 959012, 959013, 959014, 959015, 959016.