Strong moisture convergence, moderate instability and upper-level diffluence between low pressure inland and high pressure offshore led to a favorable environment for severe thunderstorms.
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.
Strong moisture convergence, moderate instability and upper-level diffluence between low pressure inland and high pressure offshore led to a favorable environment for severe thunderstorms.
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 Aug 2, 12:49 PM EST, 1 hour 51 minutes earlier.
Area Forecast Discussion National Weather Service Charleston SC 149 PM EDT Thu Aug 2 2018 .SYNOPSIS... Unsettled conditions will persist through Friday as the region remains situated between high pressure offshore and an inland trough of low pressure. Atlantic high pressure will build in for the weekend, before another inland trough develops during the early and middle parts of next week. && .NEAR TERM /THROUGH TONIGHT/... Similar changes with this update as to the last one. Radar coverage is a little higher closer to the coast so, we nudged up POPs here and blended them into the late afternoon. Expectations remain the same based on radar trends, CAMs, and the synoptic flow. Showers and thunderstorms will continue for the upcoming hours, trending inland every so slowly. Deep tropical moisture (PWATs ~2") will lead to locally heavy rainfall. Given the south to north movement of some of the storms, training is concern and could lead to areal flood advisories. The greatest risk is over the next few hours. As for the severe threat, SPC has our area under a general risk. It's not out of the question a strong, marginally few severe storm could develop this afternoon, mainly inland near the greatest deep layer shear. However, the overall risk is low given the amount of moisture in place. Plus, instability and DCAPEs are somewhat lacking. Highs may have already been reached as the convection and clouds cover are now holding temperatures in the upper 70s and lower 80s. Hence, more adjustment will be made with the hourly temperatures. Tonight: Although the intensity and coverage of showers/storms looks to decrease in the evening there will remain at least a low chance for showers and a few thunderstorms overnight as the overall pattern still doesn't change much. Probably the best rain chances will shift from GA early into SC late. Lows generally in the lower to mid 70s inland and upper 70s near the coast. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... Friday: We're set for another unsettled and soggy day, as we remain stuck between a strong and deep layered blocking anticyclone in the ocean, and an anomalous but slowly weakening mid and upper level trough from the Great lakes to the lower Mississippi valley. Moisture content remains elevated and near the 90th percentile for this time of year. There is considerable forcing from morning convergence near and along the coast, with the greater forcing to then shift inland during the afternoon as the sea breeze penetrates W. We have scattered to numerous PoP over the Charleston quad-county district in the morning, with scattered PoP elsewhere. Then for the afternoon we shift the greatest probabilities of 60-70% inland from US-17. Due to a Tutt Low lifting off the mid-Atlantic coast, it allows for the W-SW portion of the Atlantic ridge to begin to build in locally. This in turn causes the low and mid level flow to veer more SW, which may lower the risk for training cells and any significant flooding concerns. Still at least minor flooding potential exists due to the pre-existing wet grounds from above average rainfall the past couple of weeks. The overall thermodynamics do not appear favorable for much risk of any severe storms. Temps will again be held below average due to considerable cloud cover and the elevated rain chances. Saturday through Sunday: The pattern finally changes to one with decreased rain chances, but also a little hotter temps. This results from strong sub-tropical ridging that arrives form the Atlantic both surface and aloft. PWat is still between 1.5 and 2 inches Saturday, but drops to around 1.5 inches on Sunday as drier air penetrates in from the E-SE. The sea breeze will be the main focus for convection both days, with still 30-50% chances Saturday, before probabilities drop to 20-30% on Sunday. H5 heights near 5950 meters Saturday and 5960 meters Sunday, plus H8 temps around 18-19C both days will support max temps around 90 or 91F inland from the immediate and cooler coast. There might be enough instability to support a low end risk for isolated marginally severe storms where the meso- scale boundary interactions enhance updraft strength. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... Mid and upper ridging overhead early next week will drop S into the middle of next week, as various short waves help to establish a broad trough over much of the eastern half of the country. Similarly at the surface the Atlantic ridge is bumped S-SE as a lee-side trough develops. Moisture is limited by a deep offshore flow, but should be sufficient enough to combine with lift from the sea breeze and nearby trough, and typical summer instability to produce at least a chance of showers and t-storms through the period. A slight downslope component of winds and H8 temps as high as 19-20C will support max temps at least in the lower 90s each day. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... 18Z TAFs: Showers and thunderstorms will impact both TAF sites this afternoon. The areal coverage will be high enough that we have TEMPO MVFR in both TAFs. Though, adjustments will likely be made with the timing based on future radar trends. This evening the coverage will decrease, so we are indicating VCTS transitioning into VCSH. It's possible brief MVFR may occur overnight and towards the end of the TAF period. But confidence is too low to include this as a prevailing group at this time. Extended Aviation Outlook: At least periodic flight restrictions due to occasional heavy rains and gusty winds are expected in scattered to perhaps numerous SHRA/TSRA at the terminals Friday. The probabilities of SHRA/TSRA and any sub-VFR conditions will then diminish, but doesn't completely disappear from the forecast Friday night and Saturday into early next week. && .MARINE... Rest of Today and Tonight: The coastal waters will remain sandwiched between high pressure offshore and an inland trough. Expect southerly winds mainly 15 kt with some higher gusts, especially within showers/thunderstorms. Seas will average 2-4 ft. Friday through Tuesday: The Atlantic ridge centered between Bermuda and SE New England late this week will gradually build atop the waters this weekend, before it is shunted S-SE as a Piedmont trough develops early next week. Outside of convection winds and seas will be no greater than 10-15 kt and 2-4 ft, respectively. The most active times for convection will be Friday morning and again late Friday night into early Saturday morning. Waterspouts: Given lighter wind fields there appears to be some potential for isolated waterspouts each morning from Saturday through Monday. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && NEAR TERM... SHORT TERM... LONG TERM... AVIATION... MARINE...
Hazardous Weather Outlook National Weather Service Charleston SC 347 AM EDT Thu Aug 2 2018 GAZ087-088-099>101-114>119-137>141-SCZ040-042>045-047>052-030900- 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- 347 AM EDT Thu Aug 2 2018 This Hazardous Weather Outlook is for southeast Georgia and southeast South Carolina. .DAY ONE...Today and tonight. Flooding: Abundant tropical moisture could lead to heavy rainfall and localized flooding through tonight, especially in urban coastal areas such as Downtown Charleston around the times of high tide. Severe Thunderstorms: A few storms could become severe with damaging winds and/or large hail this afternoon, especially near the Midlands and Central Savannah River Area. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Flooding: Abundant tropical moisture could lead to heavy rainfall and localized flooding through Friday. .SPOTTER INFORMATION STATEMENT... Please relay any reports of hazardous weather including, but not limited to large hail, damaging winds and flooding to the National Weather Service in Charleston at 1-888-383-2024. AMZ330-350-352-354-374-030900- Charleston Harbor- 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- 347 AM EDT Thu Aug 2 2018 This Hazardous Weather Outlook is for Atlantic coastal waters. .DAY ONE...Today and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Please relay any reports of hazardous weather such as strong winds to the National Weather Service in Charleston at 1-888-383-2024.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON SC
1240 PM EDT THU AUG 02 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1206 PM TSTM WND GST 1 SE ROCKVILLE 32.59N 80.18W
08/02/2018 M46 MPH CHARLESTON SC MESONET
MESONET SITE REPORTED 40 KNOT WIND GUST AS
THUNDERSTORMS MOVED ONSHORE.
&&
EVENT NUMBER CHS1800656
ETMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON SC
1243 PM EDT THU AUG 02 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1224 PM MARINE TSTM WIND 1 SW FOLLY BEACH 32.65N 79.94W
08/02/2018 M39 MPH AMZ350 SC MESONET
WEATHERFLOW SENSOR REPORTED 34 KNOT WIND GUST.
&&
EVENT NUMBER CHS1800657
ETMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON SC
1246 PM EDT THU AUG 02 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1236 PM MARINE TSTM WIND 4 ESE CHARLESTON 32.75N 79.87W
08/02/2018 M41 MPH AMZ330 SC MESONET
WEATHERFLOW SENSOR REPORTED 36 KNOT WIND GUST.
&&
EVENT NUMBER CHS1800658
ETMSpecial Weather Statement
National Weather Service Charleston SC
255 PM EDT THU AUG 2 2018
GAZ114-137-021945-
Tattnall-Long-
255 PM EDT THU AUG 2 2018
...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF LONG AND TATTNALL
COUNTIES...
At 255 PM EDT, National Weather Service doppler radar indicated a
strong thunderstorm over Glennville, or 15 miles southeast of
Reidsville, moving north at 35 mph.
HAZARD...strong winds 45 to 55 mph and excessive cloud to ground
lightning.
IMPACT...Expect minor damage to tree limbs and blowing around of
light, unsecured objects. All outdoor activities should
cease. Move indoors immediately.
Some locations in the path of this storm include...
Reidsville, Glennville, Collins, Manassas, Gordonia Altamaha State
Park, Mendes and Donald.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm and may lead to
flooding of low lying and poor drainage areas. Do not drive your
vehicle through flooded roadways.
Report damage directly to the Charleston National Weather Service at
1-888-383-2024 when it is safe to do so. You can also email your
report to nws.charlestonsc@noaa.gov.
&&
LAT...LON 3216 8218 3225 8221 3214 8199 3208 8198
3205 8189 3204 8178 3201 8182 3197 8176
3192 8175 3174 8191 3176 8195 3179 8195
3179 8199 3182 8202 3186 8211 3190 8211
3189 8213 3191 8213 3192 8222
TIME...MOT...LOC 1855Z 161DEG 33KT 3192 8195
NEDSpecial Weather Statement
National Weather Service Charleston SC
332 PM EDT THU AUG 2 2018
GAZ099-114-022015-
Candler-Tattnall-
332 PM EDT THU AUG 2 2018
...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF CANDLER AND TATTNALL
COUNTIES...
At 331 PM EDT, National Weather Service doppler radar indicated a
strong thunderstorm near Aline, or near Metter, moving north at 20
mph.
HAZARD...strong winds 45 to 55 mph, up to penny sized hail and
excessive cloud to ground lightning.
IMPACT...Expect minor damage to tree limbs and blowing around of
light, unsecured objects. Minor hail damage to plants,
trees and crops is possible. Damage to windshields is
unlikely. All outdoor activities should cease. Move
indoors immediately.
Some locations in the path of this storm include...
Metter, Cobbtown, Manassas and Aline.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify. Be certain to monitor local radio and TV
stations as well as local cable TV outlets for additional information
and possible warnings from the National Weather Service.
Report damage directly to the Charleston National Weather Service at
1-888-383-2024 when it is safe to do so. You can also email your
report to nws.charlestonsc@noaa.gov.
&&
LAT...LON 3244 8219 3247 8218 3252 8215 3256 8209
3256 8207 3251 8198 3228 8197 3228 8203
3216 8200 3224 8221 3239 8223
TIME...MOT...LOC 1931Z 197DEG 19KT 3234 8210
NEDThe Charleston,SC radar (KCLX), 96 km away, was scanning. The volume nearest the first event began at 19:41 UTC.
2 thunderstorm wind. Local standard time, as filed.
The Candler County 911 Call Center reported a tree down on a power line along Dutch Ford Road near Brown Road.
The media reported several trees down around Statesboro.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2018Every state in 2018This day in weather historyWarnings in Georgia, August 2018
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: 777550, 777551.