Strong to severe storms developed along an old outflow boundary over portions of central Missouri. Some of the storms produced damaging winds.
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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 LSX wrote it up.
Strong to severe storms developed along an old outflow boundary over portions of central Missouri. Some of the storms produced damaging winds.
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 St. Louis, MO wrote its last area forecast discussion before the first event at Aug 6, 4:32 PM CST, 2 hours 43 minutes earlier.
Area Forecast Discussion...Updated Aviation National Weather Service Saint Louis MO 532 PM CDT Mon Aug 6 2018 .SHORT TERM... (Through Late Tuesday Afternoon) Issued at 327 PM CDT Mon Aug 6 2018 Primary concern for tonight and Tuesday will be on convective trends. Isolated to scattered diurnal activity should continue into early this evening, primarily across portions of southeast and east-central Missouri as well as southwest Illinois. Some CAMs are hinting at additional development along a remnant outflow boundary across northeast Missouri and west-central Illinois by early evening. If this convection were to develop, it would slide southeastward affecting east-central Missouri and south-central Illinois by late this evening. A few storms through early tonight may be strong to severe, with strong gusty winds the primary threat. There currently is very steep low-level lapse rates and high downdraft CAPE values as evidenced by latest SPC mesoanalysis. In addition, fairly benign cores earlier this afternoon have already produced weak microburst signatures with wind gusts in the 25-35 miles per hour range. Actual synoptic cold front will be nearing far northern sections of the forecast area late tonight and should provide the focus for additional thunderstorm development as low-level jet strengthens. However, low- level forcing for ascent does not appear too strong/focused so unsure of how widespread activity will be overnight tonight. Low-level jet is forecast to veer after midnight tonight, so expecting any convection that does form to slide at least slowly southward through dawn. Even more uncertainty with evolution of convection during the day on Tuesday, and much will depend on coverage/location of storms during the morning hours. Cold front will continue a very slow push to the south on Tuesday, so appears chances of storms will continue throughout the day. A few storms may be strong to severe across the area, especially within any areas that are able to destabilize sufficiently. With expectation that morning storms will be just north of I-70 corridor, best guess on where highest instability will reside during the afternoon hours would be parts of southeast Missouri and southwest Illinois. Temperatures on Tuesday should be heavily modulated by clouds/precipitation. Because of this increase in overall cloud cover and the possibility of more widespread shower/thunderstorm activity, temperatures should be quite a bit cooler than that experienced today. Forecast highs range from the mid to upper 80s across most of the forecast area, which is more in line with normals for the first week of August. Gosselin .LONG TERM... (Tuesday Night through Next Monday) Issued at 327 PM CDT Mon Aug 6 2018 Cold front is expected to fully clear the CWA early on Wednesday. Slightly drier and cooler air will slowly filter into the region behind this boundary. Highest chances for storms will reside across portions of southeast Missouri and southwest Illinois Tuesday night into early Wednesday. Much of the region should then be dry through Thursday night. A secondary cold front is expected to move through the bi-state region on Friday beneath northwest flow aloft. This feature will bring a chance of thunderstorms to parts of the area, mainly for Friday afternoon and evening. This front, like its predecessor, also looks to move very slowly equatorward through early this weekend. Therefore have additional chances for storms on Saturday mostly across southeast Missouri and southwest Illinois. Cutoff low pressure is forecast to develop at mid/upper levels this weekend across the Great Lakes. A shortwave trough is expected to rotate cyclonically around this cyclone into western Illinois on Sunday, bringing a slight chance of showers and thunderstorms. Temperatures are forecast to be near normal for the duration of the extended forecast. Warmest days should be on Thursday and Friday ahead of the secondary cold front with highs in the upper 80s to low 90s. Temperatures topping out in the mid to upper 80s are then favored for this weekend into next Monday. Gosselin && .AVIATION... (For the 00z TAFs through 00z Tuesday Evening) Issued at 458 PM CDT Mon Aug 6 2018 Cold front across northwest MO and southeast IA will move only slowly south-southeastward through our area tonight and Tuesday. Scattered diurnal convection will continue across the St Louis metro area into the early evening hours along thunderstorm outflow boundaries. There may continue to be isolated showers and storms later this evening into the overnight hours, but the best coverage will likely be in UIN late tonight with this nocturnal convection possibly spreading into COU and the St Louis metro area early Tuesday morning. Another round of convection is expected late Tuesday afternoon into the early evening across the St Louis metro area as the cold front moves through. Prevailing mid-high level cloudiness tonight and Tuesday outside of the convection. Surface wind will be mainly southwesterly tonight and Tuesday morning, veering around to a west-northwest direction after fropa Tuesday afternoon and evening, albeit variable at times near outflow boundaries. SPECIFICS FOR KSTL: Cold front across northwest MO and southeast IA will move only slowly south-southeastward through our area tonight and Tuesday. Scattered diurnal convection will continue across the St Louis metro area into the early evening hours along thunderstorm outflow boundaries. There may continue to be isolated showers and storms later this evening into the overnight hours, but the best coverage will likely be across northeast MO late tonight with this nocturnal convection possibly spreading into STL early Tuesday morning. Another round of convection is expected late Tuesday afternoon into the early evening as the cold front moves through. Prevailing mid-high level cloudiness tonight and Tuesday outside of the convection. Surface wind will be mainly southwesterly tonight and Tuesday morning, veering around to a west-northwest direction after fropa by Tuesday evening, albeit variable at times near outflow boundaries. GKS && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && WFO LSX
Hazardous Weather Outlook National Weather Service Saint Louis MO 338 PM CDT Mon Aug 6 2018 ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027- 034>036-041-042-047>052-059>065-072>075-084-085-099-071200- Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL- Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL- Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO- Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO- Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO- Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO- Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO- Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO- Madison MO-Reynolds MO- 338 PM CDT Mon Aug 6 2018 This hazardous weather outlook is for portions of eastern and central Missouri as well as west central and southwest Illinois. .DAY ONE...Tonight Thunderstorms are likely overnight tonight, mainly for portions of northeast Missouri and west-central Illinois. A few of these storms may be strong to severe with damaging winds the primary threat. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday Showers and thunderstorms are likely for much of the area on Tuesday. A few of the storms could be strong to severe with damaging winds and large hail the primary threats. The chance of thunderstorms continues for parts of the area Tuesday night through Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed tonight. Gosselin
Special Weather Statement National Weather Service St Louis MO 441 PM CDT MON AUG 6 2018 ILZ058-099-062215- Greene IL-Jersey IL- 441 PM CDT MON AUG 6 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN GREENE AND JERSEY COUNTIES UNTIL 515 PM CDT... At 441 PM CDT, Doppler radar was tracking a strong thunderstorm near Old Kane, moving east at 20 mph. Winds in excess of 40 mph will be possible with this storm. Locations impacted include... Jerseyville, Brighton, Kemper, Old Kane, Kane, Fieldon, Rockbridge, Otterville, Fidelity, Delhi and McClusky. LAT...LON 3904 9015 3903 9054 3921 9058 3929 9015 TIME...MOT...LOC 2141Z 262DEG 17KT 3913 9047 Tilly
The St Louis radar (KLSX), 112 km away, was scanning. The volume nearest the first event began at 01:13 UTC.
8 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds uprooted several trees and caused damage to several outbuildings including a metal roof on one of the buildings.
Thunderstorm winds blew down several large trees, numerous tree limbs and power lines around town.
A wide swath of damaging winds occurred over Audrain County from just north of Mexico southeastward towards Vandiver and Martinsburg. Numerous trees, tree limbs and power lines were blown down. Also, an outbuilding just east northeast of Vandiver sustained roof damage.
Thunderstorm winds blew down several trees and damaged a porch on a modular home in town.
Thunderstorm winds blew down several large tree limbs. One tree was blown down onto a house just east of Davis causing moderate damage.
Thunderstorm winds blew down several large trees and numerous tree limbs.
Thunderstorm winds blew down several trees and tree limbs.
Thunderstorm winds blew down several trees and numerous tree limbs around Eolia. One tree fell onto a house causing moderate damage.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Missouri in 2018Every state in 2018This day in weather historyWarnings in Missouri, 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: 780949, 780950, 780951, 780952, 780954, 780953, 780955, 780956.