The tornado outbreak of January 10–11, 2020 was a two-day severe weather event stretching from the South-Central Plains eastward into the Southeast United States. An eastward-moving shortwave trough tracked across the continental United States through that two-day period, combining with abundant moisture, instability, and wind shear to promote the formation of a long-lived squall line. Hundreds of damaging wind reports were received, and 80 tornadoes occurred within this line, making it the third largest January tornado outbreak on record. Three tornadoes—an EF1 in eastern Texas, an EF2 in northern Louisiana, and an EF2 in western Alabama—led to a total of seven deaths, all in mobile homes. There were five other storm related deaths, including two due to icy roads in Lubbock, Texas, one due to drowning in Oklahoma, and one due to icy roads in Iowa. The system also brought a monthly record high temperature to Boston and Bridgeport.Winter Interrupted by Record Warmth in the Northeast, AccuWeather, January 11, 2020Cooler weather on the way after record highs, Pix11, January 12, 2020 Extensive damage and several other injuries occurred as well. The severe weather event was notable in that it was forecast well in advance, with the Storm Prediction Center first highlighting the risk area a full week beforehand. Total damage from the event reached $1.1 billion according to the National Centers for Environmental Information.
Meteorological synopsis Beginning on January 5, the Storm Prediction Center (SPC) highlighted the potential for organized severe weather across central Texas eastward into far western Georgia valid for January 10–11. The day 7 outlook issued that day constituted only the fourth time a severe weather risk had been delineated a week in advance in January, alongside January 23, 2013, January 18, 2010, and January 1, 2008. Despite the unusually high confidence at a long lead time, the threat region aligned well with climatologically favored areas for severe weather during the month. On January 6, the day 6 outlook for January 10 raised portions of northeastern Texas, northwestern Louisiana, southeastern Oklahoma, and southern Arkansas to a 30% probability of severe weather, equivalent to an Enhanced risk. Much of Alabama and Mississippi, in addition to a small section of both Louisiana and Florida, were upgraded to an Enhanced risk in the following day's outlook as well. On January 9, after days of refining the risk area, the SPC elevated northeastern Texas, northern Louisiana, and far southern Arkansas to a Moderate risk. Although the Moderate risk was initially issued given high confidence in a widespread damaging wind event, including the potential for a derecho, the morning outlook on January 10 raised the potential for strong, long-tracked tornadoes across eastern Texas, northern Louisiana, southern Arkansas, and extreme western Mississippi.
At the start of the day, a cold front was analyzed from south-central Kansas southwestward into an area of low pressure across the Texas Panhandle. In advance of this front, persistent warm-air advection led to quickly-rising dewpoints across western Oklahoma and far south-central Kansas. Aloft, a deep shortwave trough across the Southwestern United States pushed eastward, resulting in cold mid-level temperatures and the development of a modestly unstable environment. In the presence of strong wind shear, and given the impetus for convective development, thunderstorms mainly capable of a severe hail threat began to form throughout the morning hours. Intensifying thunderstorms farther east across central and eastern Oklahoma led to the day's first tornado watch at 16:40 UTC. Numerous other tornado and severe thunderstorm watches were issued as the day progressed. As the cold front shifted eastward, a line of thunderstorms developed along this boundary from southern Missouri down into central Texas. Despite the expectation that supercells capable of strong tornadoes would precede this line, convection instead failed to organize in an unstable but slightly capped environment. The SPC ultimately decided to downgrade tornado probabilities and remove the hatched area denoting the potential for strong tornadoes in their 01:00 UTC outlook.
Throughout the overnight hours, the southern edge of the convective line surged eastward at an increasing rate, leading to interaction with pre-frontal thunderstorms that increased rotation in an already volatile environment. Numerous embedded rotations and semi-discrete supercell structures formed within the line, producing many tornadoes. An EF1 tornado west-southwest of Nacogdoches, Texas, led to the death of one person, while a long-tracked EF2 tornado that tracked from southeast of Bossier City to north of Arcadia, Louisiana, led to three more fatalities. All four deaths from these two tornadoes were in mobile homes. By the afternoon hours of January 11, the already intense line of convection consolidated further as instability increased and an upper-level trough approached from the west. A high-end EF2 tornado caused severe damage near Carrollton, Alabama, causing three deaths between two manufactured homes that were demolished. Numerous other tornadoes and hundreds of damaging wind reports were recorded throughout the afternoon, but the squall line began to weaken late on January 11 as the forcing mechanism lifted northeast into the Ohio River Valley and as daytime heating waned.
Confirmed tornadoes
January 10 event + List of confirmed tornadoes – Friday, January 10, 2020EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax width EF0PragueLincolnOK16:34–16:37A weak tornado damaged a few homes and destroyed a few sheds or outbuildings in Prague. EFUSE of MurphyMayesOK17:55–17:56Multiple storm chasers observed a tornado, but the area where it occurred was inaccessible by road, so no damage is known to have occurred. EF1WNW of Fair PlayCedar, PolkMO20:27–20:41A manufactured home and several outbuildings were destroyed by this high-end EF1 tornado. Several homes sustained damage, and several trees were snapped or uprooted. EF0WNW of BoydWiseTX20:46–20:47A barn was destroyed, with debris scattered downstream. A nearby gas station was damaged, along with some tree limbs. EF1WNW of KeysCherokeeOK20:49–20:57The roofs of a house and two mobile homes were damaged. A number of trees were uprooted, and some outbuildings were damaged as well. EF1E of Cross TimbersHickoryMO21:20–21:23An outbuilding was destroyed, numerous trees were snapped or uprooted, and two homes sustained minor roof damage. EF1NE of GodleyJohnsonTX23:41–23:47The roofs and awnings of several homes and buildings were damaged. A barn was flipped and blown into the side of a house. A large horse trailer was moved, an 18-wheeler trailer was overturned, and a small storage shed was damaged. Four power poles were leaned over as well. EF1E of Springfield to StraffordGreeneMO23:42–23:53An automobile service building lost overhead doors and sustained roof damage. Several homes suffered significant roof damage and damage to gutters and garage doors. Two box trucks were overturned, and numerous trees were snapped and uprooted. A large metal building sustained damage to its overhead doors. EF0CooperDeltaTX00:15–00:17A brief tornado destroyed a small outbuilding and tore the roof and part of a cinder block wall from a small commercial building. A large sheet metal building was seriously damaged and an apartment complex in town suffered siding damage. Other structures and some trees suffered minor damage. EF0SE of EnloeDeltaTX00:22–00:23Another brief tornado was spawned by the same supercell as the Cooper tornado. A couple of small outbuildings were destroyed with debris scattered a few hundred yards downwind in a subtle cyclonic pattern. EF0Northern IrvingDallasTX00:42–00:44A grocery store and other structures sustained roof damage. The exterior wall of a hotel, the roofs and windows of two restaurants, trees, light poles, and commercial signs were damaged. EF2NE of Cove Lake to ENE of TokalonLoganAR01:44–02:02One mobile home and a barn were destroyed, and another mobile home was damaged. Homes lost large sections of their roofs but most of their walls remained. Other outbuildings and chicken houses were damaged or destroyed. Trees and power lines were knocked down along the path. EF1E of CecilFranklinAR01:45–01:49Several outbuildings were destroyed, the roof of a home was damaged, numerous trees were snapped or uprooted, and power poles were toppled. EF1WSW of CaldwellBurlesonTX03:34–03:35A shed was destroyed and a trailer was thrown to the south while debris was blown to the northeast. Numerous trees were snapped. EF1NW of RuskCherokeeTX05:21–05:22A shed was destroyed and the roofs of five homes were damaged. Trees were uprooted. EF1WSW of NacogdochesNacogdochesTX05:33–05:361 death – Trees were knocked down and large tree branches were broken. One tree fell into a mobile home, killing one person and injuring another. Several other homes suffered minor damage. EF1N of CushingRuskTX05:43–05:50Several farm outbuildings were tossed and demolished, and two houses sustained roof damage. Numerous trees were snapped and uprooted. EF1NE of PollokAngelinaTX05:53–05:54A double wide mobile home was lifted up and shifted off its foundation, and a trailer was flipped. Trees and tree limbs were snapped in a convergent pattern.
January 11 event