Convection initiated due to the lee side trough, the sea breeze and plentiful outflow boundary mergers. With DCAPE around 1500 j/kg it didn't take much for downburst winds to occur.
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.
Convection initiated due to the lee side trough, the sea breeze and plentiful outflow boundary mergers. With DCAPE around 1500 j/kg it didn't take much for downburst winds to occur.
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 Jul 3, 12:35 PM EST, 1 hour 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 135 PM EDT TUE JUL 3 2012 .SYNOPSIS... A STRONG UPPER RIDGE WILL REMAIN WEST OF THE AREA THIS WEEK WHILE A SURFACE TROUGH PERSISTS INLAND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NO CHANGES NEEDED DURING THE EARLY AFTERNOON UPDATE. STATISTICAL GUIDANCE FROM NAM AND GFS ARE VERY DRY OVER THE AREA SHOWING LITTLE IF ANY CHANCE FOR CONVECTION LATER TODAY...BUT SOME OF THE HI-RES MODELS STILL INDICATE THE POSSIBILITY OF ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS ALONG THE SEA BREEZE AS IT MOVES INLAND...SO I WILL NOT LOWER THE POPS ANY FURTHER THAN CURRENTLY IN THE FORECAST. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... TONIGHT...ANY LINGERING CONVECTION WILL QUICKLY END BY MID TO LATE EVENING AS THE SEA BREEZE CLEARS THE FAR WESTERN AREAS AND INSTABILITY WANES. DEBRIS CLOUDINESS WILL GRADUALLY THIN WITH TIME...BUT UPSTREAM CIRRUS WILL CONTINUE TO CROSS THE AREA OVERNIGHT. TEMPERATURES WILL BOTTOM OUT IN THE LOWER-MID 70S...EXCEPT UPPER 70S/NEAR 80 AT THE BEACHES AND IN DOWNTOWN CHARLESTON. WEDNESDAY THROUGH FRIDAY...THE GENERAL SYNOPTIC PATTERN WILL REMAIN RELATIVELY UNCHANGED THROUGH FRIDAY. AT THE SURFACE...A PERSISTENT INLAND TROUGH WILL STRENGTHEN AND SLIP CLOSER TO THE COASTLINE AS THE WEEK PROGRESSES. AT THE UPPER LEVELS...RIDGING WILL BECOME CENTERED TO THE WEST...WHILE A PROGRESSIVE TROUGH ALOFT WITH EMBEDDED SHORTWAVE ENERGY SLIPS DOWN THE EAST COAST. ISOLATED TO SCATTERED CONVECTION IS POSSIBLE EACH AFTERNOON...AS A WEAKER CAPPING INVERSION ALLOWS TYPICAL SEA BREEZE CONVERGENCE TO INITIATE DIURNAL THUNDERSTORM ACTIVITY. ADDITIONAL CONVERGENCE WITHIN THE SURFACE TROUGH STRETCHING ACROSS THE SOUTH CAROLINA MIDLANDS AND CENTRAL SAVANNAH RIVER REGION WILL SUPPORT UPSTREAM CONVECTION THAT COULD PROGRESS INTO THE FORECAST AREA EACH EVENING WITHIN DEEP WESTERLY FLOW ALOFT. SOME NUMERICAL MODEL SOLUTIONS EVEN SUGGEST THAT UPPER LEVEL FORCING WITHIN THE TROUGH ALOFT COULD ALLOW THE EVENING CONVECTION TO PERSIST INTO THE OVERNIGHT HOURS. HAVE THUS MAINTAINED A SLIGHT CHANCE FOR SHOWERS/THUNDERSTORMS TO CONTINUE INTO THE NIGHTTIME PERIODS BOTH WEDNESDAY AND THURSDAY. STEADILY FALLING HEIGHTS ALOFT THROUGH FRIDAY WILL MAINTAIN A GRADUAL COOLING TREND. HIGH TEMPERATURES WILL STILL RISE ABOVE SEASONAL NORMALS...REACHING THE MID TO UPPER 90S AWAY FROM THE COAST ON WEDNESDAY AND THE LOW TO MID 90S BY THURSDAY AND FRIDAY. DEW POINTS WILL STILL LINGER IN THE LOW TO MID 70S EACH AFTERNOON...YET THE DECREASING TEMPERATURES WILL KEEP HEAT INDICES BELOW ADVISORY CRITERIA. && .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/... THE BROAD TROUGH ALOFT WILL BEGIN TO DIMINISH THROUGH THE WEEKEND...WITH A WEAK RIDGING PATTERN DEVELOPING IN ITS PLACE. MOISTURE AND CONVERGENCE WILL REMAIN ENHANCED WITHIN AN INLAND SURFACE TROUGH THAT WILL UNDERGO SEVERAL STAGES OF WEAKENING AND STRENGTHENING THROUGH THE PERIOD. LATEST NUMERICAL MODEL SOLUTIONS SUGGEST THE SURFACE PATTERN WILL BE WEAKEST FRIDAY AND SATURDAY...AS THE ATLANTIC RIDGE ATTEMPTS TO BUILD BACK OVER THE COASTLINE. THE SURFACE TROUGH THEN RESTRENGTHENS FROM THE NORTH SUNDAY AND MONDAY...AS SOME ADDITIONAL SHORTWAVE ENERGY SLIPS INTO THE REGION FROM THE GREAT LAKES. WILL MAINTAIN MENTION OF ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS EACH DAY ACCORDINGLY...ESPECIALLY DURING THE TIMES OF MAX HEATING/INSTABILITY OF THE AFTERNOON/EARLY EVENING HOURS. HIGH TEMPERATURES WILL GENERALLY RANGE FROM THE LOW TO MID 90S EACH AFTERNOON...STILL A FEW DEGREES WARMER THAN SEASONAL NORMALS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE 18Z TAFS. ISOLATED CONVECTION IS EXPECTED TO DEVELOP THIS AFTERNOON...BUT COVERAGE SHOULD REMAIN QUITE LIMITED. EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER THAN 30 PERCENT CONFIDENCE LEVEL. && .MARINE... SOUTHERLY WIND REGIME WILL PERSIST INTO TONIGHT. WINDS WILL REMAIN 15 KT OR LESS THROUGH THE PERIOD WITH SEAS 2-4 FT. WEDNESDAY THROUGH SATURDAY...THE MARINE AREA WILL BE GENERALLY BE LOCATED BETWEEN ATLANTIC HIGH PRESSURE TO THE EAST AND AN INLAND TROUGH TO THE WEST/NORTHWEST THROUGH THE PERIOD. SOUTH TO SOUTHWEST WINDS AT OR BELOW 15 KT WILL PREVAIL INTO EARLY NEXT WEEK...WITH SEAS 1 TO 3 FT ACROSS THE NEARSHORE WATERS AND 3 TO 4 FT ACROSS THE OUTER MARINE ZONES. THE INLAND SURFACE TROUGH WILL BE ON A STEADY STRENGTHENING TREND AS THE WEEK PROGRESSES...TIGHTENING THE PRESSURE GRADIENT WITH THE ATLANTIC SURFACE HIGH. SOUTH/SOUTHWEST FLOW COULD SURGE UP TO 15 TO 20 KT AT TIMES...ESPECIALLY BY LATER IN THE WEEK. HOWEVER WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA. && .TIDES/COASTAL FLOODING... THE UPCOMING FULL MOON COMBINED WITH THE PERIGEAN SPRING TIDES WILL RESULT A RISK FOR SHALLOW COASTAL FLOODING NEAR THE TIMES OF HIGH TIDE DURING THE EVENING HOURS THIS EVENING THROUGH MUCH OF THE WEEK. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...NONE. MARINE...NONE. && SYNOPSIS... NEAR TERM...ALSHEIMER SHORT TERM...ALSHEIMER LONG TERM...BSH AVIATION...JHP MARINE...ALSHEIMER/BSH TIDES/COASTAL FLOODING...
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE CHARLESTON SC 323 AM EDT TUE JUL 3 2012 AMZ350-352-354-374-GAZ087-088-099>101-114>119-137>141-SCZ040-042>045- 047>052-040730- 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 EXTENDING FROM 20 TO 60 NM-JENKINS-SCREVEN-CANDLER-BULLOCH-EFFINGHAM-TATTNALL-EVANS- INLAND BRYAN-COASTAL BRYAN-INLAND CHATHAM-COASTAL CHATHAM-LONG- INLAND LIBERTY-COASTAL LIBERTY-INLAND MCINTOSH-COASTAL MCINTOSH- ALLENDALE-HAMPTON-INLAND COLLETON-DORCHESTER-INLAND BERKELEY- INLAND JASPER-BEAUFORT-COASTAL COLLETON-CHARLESTON-COASTAL JASPER- TIDAL BERKELEY- 323 AM EDT TUE JUL 3 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS...SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. AMZ330-040730- CHARLESTON HARBOR- 323 AM EDT TUE JUL 3 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. 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 CHARLESTON SC
213 PM EDT TUE JUL 3 2012
GAZ088-031845-
SCREVEN-
213 PM EDT TUE JUL 3 2012
...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF SCREVEN COUNTY
THROUGH 245 PM EDT...
AT 211 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM...6 MILES NORTHEAST OF GREEN HILL...MOVING SOUTH
AT 10 MPH.
SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
ALTMAN...CAPTOLO...HUNTERS...NEWINGTON...OLIVER AND SYLVANIA...
PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 40 TO 50 MPH...
DIME SIZE HAIL...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AS STORMS APPROACH.
BE READY TO TAKE IMMEDIATE ACTION IN CASE A SEVERE THUNDERSTORM
WARNING IS ISSUED FOR YOUR LOCATION.
&&
LAT...LON 3286 8164 3284 8144 3277 8142 3277 8143
3271 8141 3270 8143 3269 8141 3264 8140
3263 8142 3260 8139 3252 8152 3250 8155
3260 8171
TIME...MOT...LOC 1814Z 012DEG 10KT 3277 8153SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
251 PM EDT TUE JUL 3 2012
SCZ040-042-031915-
ALLENDALE-HAMPTON-
251 PM EDT TUE JUL 3 2012
...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF ALLENDALE AND HAMPTON
COUNTIES THROUGH 315 PM EDT...
AT 250 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS...ALONG A LINE EXTENDING FROM ROUSE TO
GIFFORD...MOVING SOUTH AT 5 MPH.
SOME LOCATIONS THAT WILL BE AFFECTED INCLUDE...
ALLENDALE...APPLETON...BARTON...BRUNSON...ESTILL...FAIRFAX...
GIFFORD...LENA...LURAY...MARTIN...SEIGLING...SYCAMORE AND ULMER...
PREPARE NOW FOR THE FOLLOWING HAZARDS...
GUSTY WINDS OF 40 TO 50 MPH...
PENNY SIZE HAIL...
PRECAUTIONARY/PREPAREDNESS ACTIONS...
BE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AS STORMS APPROACH.
BE READY TO TAKE IMMEDIATE ACTION IN CASE A SEVERE THUNDERSTORM
WARNING IS ISSUED FOR YOUR LOCATION.
&&
LAT...LON 3311 8136 3311 8129 3309 8115 3274 8119
3276 8141 3276 8142 3281 8143 3284 8142
3285 8144 3315 8151
TIME...MOT...LOC 1852Z 000DEG 3KT 3288 8133 3284 8127The Charleston,SC radar (KCLX), 49 km away, was scanning. The volume nearest the first event began at 18:55 UTC.
7 thunderstorm wind, 1 hail. Local standard time, as filed.
The public reported a downed tree 7 miles outside of Sylvania.
The Georgia Forestry Commission reported a few large limbs down. Limbs were greater than 6 inches in diameter.
The public reported one tree and one power line down.
The Bulloch County 911 Center reported several trees down near Nevils.
The Evans County 911 Center relayed a report of 1 tree down along Tippins Road.
The Tattnall County 911 Center relayed a report of a pecan tree down along Anderson Church Road.
The Tattnall County 911 Center relayed a report of dime size hail and 2 trees down near Collins.
Quarter sized hail reported via Bryan 911 call center.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2012Every state in 2012This day in weather historyWarnings in Georgia, July 2012
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: 400841, 400842, 400843, 400844, 400845, 400846, 400847, 400840.