From May 18–21, 2013, a significant tornado outbreak took place across parts of the Midwestern United States and lower Great Plains. This event occurred just days after a deadly outbreak struck Texas and surrounding southern states on May 15. On May 16, a slow moving trough crossed the Rockies and traversed the western Great Plains. Initially, activity was limited to scattered severe storms; however, by May 18, the threat for organized severe thunderstorms and tornadoes greatly increased. A few tornadoes touched down that day in Kansas and Nebraska, including an EF4 tornado near Rozel, Kansas. Maintaining its slow eastward movement, the system produced another round of severe weather nearby. Activity significantly increased on May 19, with tornadoes confirmed in Oklahoma, Kansas, Iowa, Missouri, and Illinois. In Oklahoma, two strong tornadoes (one rated EF4) caused significant damage in rural areas of the eastern Oklahoma City metropolitan area; two people lost their lives in Shawnee. The most horrific events unfolded on May 20 as a large EF5 tornado devastated parts of Moore, Oklahoma, with 24 people killed. Thousands of structures were destroyed, with many being completely flattened. Several other tornadoes occurred during the day in areas further eastward, though the majority were weak and caused little damage.
The severe threat shifted towards damaging straight-line winds on May 21 as a large squall line developed across the southern states. Further north in Ontario, three tornadoes, including one that was rated EF2, touched down. Over the following five days, the system responsible for the outbreak moved very little across the Eastern United States. By May 24, it virtually stalled off the coast of New England, resulting in several days of heavy rain across the region. It later moved northeastward and was last noted by the Weather Prediction Center late on May 26 over southeastern Canada. During the storm's eleven-day trek across the United States, it produced 75 tornadoes, 4 of which were rated EF3 or higher. Over 1,000 reports of damaging winds were received by the Storm Prediction Center as well. The system's slow movement also resulted in record-breaking rains in North Dakota, New York, and Vermont. Additionally, during the overnight of May 25 – 26, unusually cold air behind the cyclone resulting in record-late snows across northern New England.
Confirmed tornadoes
May 18 event + List of confirmed tornadoes – Saturday, May 18, 2013EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax widthSummary EF0WSW of Cedar Bluff ReservoirTregoKS2227 – 2236A tornado tracked over open fields and caused no damage. EF0N of BroadwaterMorrillNE2258 – 2301A brief tornado caused no damage. EF0NNW of BrownellNessKS2303 – 2305A brief multiple-vortex tornado caused no damage. EF1SSW of EllisEllisKS2309 – 2312Several trees and power poles were damaged. EF0NW of AntoninoEllisKS2337 – 2339A brief tornado caused no damage. EF4W of RozelPawneeKS0018 – 0047Five farm houses were damaged by this large, cone-shaped tornado, one of which had most of its roof and some of its exterior walls destroyed at the house (the other four sustained minor damage). An outbuilding was destroyed, another outbuilding suffered minor damage, and a large propane tank was ripped off of its concrete foundation and tossed . Many trees and power lines were downed, seven irrigation pivots were flipped, and part of a road was scoured as well. The EF4 rating was confirmed based on Doppler on Wheels surface wind observations of . EF1ENE of SanfordPawneeKS0049 – 0101This tornado developed to east of the previous event and damaged trees and power poles. EF0SSE of Ash ValleyPawneeKS0110 – 0113This was the third tornado associated with the supercell that spawned the EF4 Rozel storm; no damage occurred. EF1NW of Clay CenterClay, WashingtonKS0335 – 0345Irrigation pivots were overturned, trees were downed, and outbuildings were destroyed. EF0Southern WashingtonWashingtonKS0400 – 0402Several trees were downed and large tree limbs were torn. A barn also lost its roof.
May 19 event + List of confirmed tornadoes – Sunday, May 19, 2013EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax widthSummary EF0SW of ViolaSumnerKS2010–2012A brief tornado remained over open country, causing no damage. EF0E of ViolaSedgwickKS2019–2024A brief rope tornado moved over open country, causing no damage. EF2NNE of ClearwaterSedgwickKS2037 – 2048A silo was destroyed, a trailer was blown into outbuildings, and a brick home suffered roof damage. A horse trailer was rolled , another trailer was rolled , and two irrigation pivots were flipped over. A plank of wood was thrown through a car window and an outbuilding was moved off of its foundation. Several trees and power poles were downed as well. The Doppler on Wheels recorded peak winds of at above ground level. EF0SW of WellingtonSumnerKS2112–2113A trained spotter observed a brief tornado in an open field; no damage was reported. EF1EdmondOklahomaOK2122 – 2130Twelve homes in the town were damaged, including three that sustained major damage. Nine transmission towers were also destroyed by the tornado and it was estimated that it would take a month to replace them. EF1SW of ArcadiaOklahomaOK2133 - 2134A power pole was damaged. EF0WSW of South HavenSumnerKS2139–2141A brief tornado was reported by a trained spotter; no damage occurred. EF0S of South HavenSumnerKS2140–2141A rope tornado was reported; no damage occurred. EF3NW of Luther to SE of TryonOklahoma, Logan, LincolnOK2141 – 2224This large multiple-vortex wedge tornado destroyed an outbuilding and two mobile homes shortly after touching down. Along I-35, a hospital that was under-construction had windows blown out and its roof damaged. The tornado clipped the southeastern edge of Carney, damaging or destroying 40 homes and a few industrial buildings there. Power and water supply was knocked out to the town as well. Debris from Carney was reported to have fallen up to away in Hallett. Video of this tornado revealed extremely violent motions within the funnel, indicating that the tornado may have been stronger than EF3 intensity, but there were no damage indicators to confirm this. Four people were injured. EF1SE of UdallCowleyKS2146 – 2148A tornado that was reported by a spotter caused minor damage to a farmstead. EF1NE of WolbachGreeleyNE2151 – 2153A short-lived tornado destroyed a mobile home and shed. Several trees were downed as well. EF1E of UdallCowleyKS2155 – 2159Minor damage occurred at a farmstead. EF0SW of RamonaMarionKS2205–2207Law enforcement observed a brief tornado; no damage was reported. EF0N of RamonaDickinsonKS2217The Ramona volunteer police department reported a brief tornado touchdown; no damaged occurred. EF1SE of EmporiaLyonKS2227 – 2237A home and an outbuilding were damaged just west of the Emporia Municipal Airport shortly after the tornado touched down. Sporadic tree damage occurred along the rest of the path. EF0N of Arkansas CityCowleyKS2259–2300A brief tornado moved over open country with no damage being reported. EF4E of Norman to ESE of McLoudCleveland, PottawatomieOK2300 – 23502 deaths – See section on this tornado – Ten people were injured. EF0Southwestern AdelDallasIA2332 – 2335A weak tornado, which formed within a very broad circulation, produced a short, intermittent path before dissipating prior to reaching populated areas of Adel. EF0N of Bethel AcresPottawatomieOK2340 - 2343RaXPol mobile radar data confirmed that an anticyclonic tornado, which was a satellite to the long-tracked Lake Thunderbird–Shawnee EF4 tornado, damaged trees. EF1ESE of Dallas CenterDallasIA2345 – 2348A house suffered significant structural damage and numerous trees were downed. EF0WNW of ShamrockCreekOK2347 - 2348A brief tornado caused no damage. EF2W of PraguePottawatomie, LincolnOK2359 – 0012A house was pushed off of its cinder block foundation and numerous sheds/outbuildings were either damaged or destroyed. Two more houses lost much of their roofs and exterior walls and a fourth house suffered roof, wall, and window damage. A fifth house sustained minor roof damage, an RV was rolled, and many trees were downed. EF1SSE of Slater to SSE of HuxleyPolk, StoryIA0007 – 0012An intermittent tornado removed a garage and part of the roof from a manufactured home. EF1NNE of Prague to NW of WeltyLincoln, Okfuskee, CreekOK0017 – 0040Barns and outbuildings were damaged and numerous trees were downed. EF0E of Argo FayCarrollIL0102Emergency management reported a brief tornado; no damage was reported.
May 20 event