A relatively widespread, damaging, and deadly tornado outbreak and severe flooding struck the central and southern United States in late April 2014, with the bulk of the activity occurring on April 27 and 28. The storm complex responsible for the outbreak produced multiple long-track and intense to violent tornadoes – seven of which were deadly, causing 35 fatalities.U.S. tornadoes kill 35 over 2 days, CBC News (via the Associated Press), April 29, 2014. One additional death occurred in Florida, due to severe flooding associated with this system. On April 27, the Storm Prediction Center (SPC) first issued a high risk for parts of Arkansas, as a broad upper-level trough slowed over the High Plains and Central United States, where strong tornadic activity occurred, including a violent high-end EF4 tornado that devastated the towns of Mayflower and Vilonia that evening, killing 16 and injuring nearly 200, necessitating the issuance of a tornado emergency. Multiple other strong tornadoes touched down that night as well.
April 28 saw the most prolific tornado activity, with another high risk issued by the SPC and a particularly dangerous situation tornado watch for parts of central Mississippi and Alabama, and multiple intense to violent tornadoes touched down across the Deep South. Another violent high-end EF4 tornado struck the town of Louisville, Mississippi, killing ten and injuring 84. A few more deadly tornadoes touched down in Tennessee and Alabama that night; including an EF3 near Flintville, Tennessee that killed two – several more tornado emergencies were issued that day as well, the most in a single day since the March 2, 2012 tornado outbreak. Scattered activity and weaker tornadoes occurred on April 29 and 30 across the eastern U.S. before the outbreak came to an end.
This event was the first major tornado outbreak to hit the United States in 2014; it covered a large swath from Nebraska to Louisiana, Illinois to Florida, and Oklahoma to North Carolina. This system affected millions in the Northeastern United States on April 30, causing significant, damaging floods in Maryland, Baltimore Brew, April 30, 2014. and flash flood advisories as far north as New Jersey, Pennsylvania, and the metropolitan area and suburbs of New York City.Dangerous Flash Flooding, Storms Threaten I-95 Wednesday Evening, AccuWeather, April 30, 2014. With a grand total of 82 tornadoes over a four-day period, the tornado outbreak gained 97 points on the outbreak intensity score.
Severe and catastrophic flash flooding also occurred in the Deep South, due to a slow-moving cold front associated with the tornado outbreak. It dumped a record setting amount of rainfall, inundating the western Florida Panhandle and Southwest Alabama. Pensacola was estimated to have received as much as 26 inches of rain in only 25 hours, with 5.68 inches of it falling in only an hour at Pensacola International Airport. A landslide caused a major portion of Scenic Highway in Pensacola to collapse into the bay it overlooks. Areas east of Pensacola received as much as 15–20 inches of rain, peaking at 20.39 inches in Milton and 14.15 inches at Mary Esther. The majority of this rainfall occurred in a time period of about 9 hours on the morning of April 30. In Alabama, rainfall amounts peaked at 23.67 inches in Orange Beach, and 17.20 inches in Mobile.
Meteorological synopsis The Storm Prediction Center (SPC) indicated the potential for a large-scale tornado outbreak for six days in advance on its 4–8 day outlook, beginning early on April 19 valid at day 5. While models diverged on the exact nature and intensity of the expected mid-level shortwave trough, there was broad support for a dry line to develop in central Oklahoma. By April 22, the SPC expanded the threat zone for day 6 for the remainder of Oklahoma and central High Plains region, with strong upper-level winds to spread over the central High Plains. Three days later, a Day 3 moderate risk was issued early on April 25 for the Ark-La-Tex region, citing the increased risk for a severe weather outbreak, with the risk of trailing supercells.
April 27
The strong mid-level shortwave trough developed into a closed low-pressure area as the system occluded over the central High Plains on April 27, 2014. An associated surface cyclone reached peak intensity while a trailing cold front moved eastward across eastern Kansas, eastern Oklahoma and northern Texas. There were two areas where severe weather was expected: morning pre-frontal convection from Kansas and Oklahoma into Missouri and Iowa and warm sector supercell development across southeast Oklahoma and northeast Texas into Arkansas. By 20:00 UTC on April 27, the SPC issued a rare high risk for much of central Arkansas and a 30% hatched risk for tornadoes across the same corridor, citing the anticipation of numerous supercells capable of producing intense tornadoes. Expected thermodynamic conditions of storm-relative helicity values in of 300–400 m2s−2, convective available potential energy (CAPE) values of 2,500–3,000 J/kg−1, a 40–50 kn low level jet and boundary-layer dewpoints of were expected to foster supercell development and strong to intense tornadoes across Arkansas, along with very large hail. A particularly dangerous situation (PDS) tornado watch was issued at that time for central Arkansas.
As the evening progressed, multiple intense tornadoes touched down across parts of the Midwest, Ozarks, and Great Plains. A strong EF2 tornado struck Quapaw, Oklahoma and Baxter Springs, Kansas, resulting in one fatality, 37 injuries, and severe damage in both towns. An EF1 tornado destroyed multiple outbuildings, killing two people as it passed near Martinsburg, Iowa. A large, violent wedge tornado struck Mayflower and Vilonia, Arkansas later that evening, causing catastrophic damage and killing 16 people as numerous homes and businesses were obliterated, some of which were swept completely away. Trees were completely denuded and debarked, vehicles were thrown and mangled beyond recognition by the tornado, which was rated a high-end EF4, the first violent tornado of the year.
April 28
On April 28, morning storms that were present over Mississippi, Alabama, and Tennessee began dissipating over time, leaving a well-defined outflow boundary across south-central Tennessee and more diffuse across the northern parts of Mississippi and Alabama. The morning storms dissipating also allowed strong surface heating to start across Louisiana and southwest Mississippi, with further clearing expected to occur. By the afternoon, weakening convective inhibition allowed storm development along or east of the outflow boundary. Mid-level convective available potential energy (CAPE) was expected to be near 2,000 j/kg, with strong bulk shear of , storm-relative helicity at 200-300 ms2/s2, and subtle forcing favored a discrete or cluster supercells mode. With all these variables, at 2:19 p.m. CDT, the SPC upgraded to a high risk for most of central Mississippi and parts of Alabama, accompanied by a 30% hatched risk for strong to violent tornadoes.
At 12:40 p.m. CDT, a particularly dangerous situation tornado watch was issued most of Mississippi, parts of Louisiana, Alabama, and southern Tennessee, with some long-lived supercells capable of producing strong and long-tracked tornadoes. The tornado watch noted that surface based storm were beginning to develop in Louisiana and Mississippi as more clearing occurred and atmospheric destabilization continued, a combination of a moderate ML CAPE and strong deep vertical wind shear supported a broken band of supercells, with an increase in low-level shear expected across central Mississippi, northwest Alabama, and southern Tennessee along the outflow boundary.
By 3:49 p.m. CDT, numerous discrete and clustered supercells were moving northwest from central Mississippi into northwest Alabama, with the damaging Tupelo EF3 tornado already occurring within the past hour as more discrete supercells initiated south into central Mississippi, suggesting that these storms will more likely remain separated for a few more hours, increasing support for long-tracked and significant tornadoes. Local observations showed an expected strengthening of the wind profiles and additional support from the low-level flow associated with surface pressure deepening, boosting storm relative helicity. Strong to violent tornado damage was expected over the next few hours with the most potent supercells. Destructive tornadoes continued to touch down later that evening, and 10 people were killed when an EF4 tornado struck Louisville, Mississippi, where many homes, apartment buildings, and businesses were completely destroyed, some of which were leveled or swept away. An EF3 tornado caused one fatality and major damage to many structures in Tupelo, Mississippi as well, and another EF3 struck Coxey, Alabama, destroying a mobile home park and killing two people. Numerous other strong tornadoes occurred in rural areas of the Deep South later that night and into the early morning hours of April 29.
April 29–30 Additional weak tornadoes touched down in The Carolinas and Florida on April 29 and 30 before the outbreak came to an end. 82 tornadoes were confirmed as a result of this outbreak, which resulted in 35 fatalities. In addition to the tornado outbreak, a lone EF0 tornado occurred in Pierce County, Washington on April 27, causing minor damage.
Confirmed tornadoes
A total of 82 tornadoes over a period of four days were confirmed. Collectively, they resulted in 35 fatalities and 447 injuries.
Quapaw, Oklahoma/Baxter Springs, Kansas
The first significant tornado of the outbreak touched down over an open field at 5:29 p.m. CDT (2229 UTC) on April 27 to the southwest of Quapaw, Oklahoma and caused EF0 damage to a ranch. It caused minor damage to homes and downed trees as it neared US 69A. Shortly thereafter, it struck the town of Quapaw at high-end EF2 strength and caused extensive damage. The local fire station was largely destroyed, and some industrial buildings sustained heavy damage. Homes in town were shifted off of their foundations or sustained loss of roofs and walls. Two people seeking shelter from the tornado in their car were struck by debris from the building they were next to; one of the occupants was killed while the other was injured. A total of 12 people were injured in the town, 7 of whom required hospitalization. A total of 50 structures were damaged or destroyed in Quapaw.
The storm continued northeast and crossed the Oklahoma–Kansas state line, causing EF1-strength damage to outbuildings and downing trees and power poles. It soon moved directly through the town of Baxter Springs at high-end EF2 strength, where many homes and businesses lost their roofs, several of which had their exterior walls collapse. 90 homes and 11 businesses were destroyed, and an additional seven businesses and 85 homes suffered damage in Baxter Springs. A total of 34 people were injured in town, 9 of whom were hospitalized. The tornado continued northeast and eventually dissipated from the town at 5:42 p.m. CDT (2242 UTC). Overall, the tornado remained on the ground for 13 minutes along a path, causing 1 death and 37 injuries.
This particular tornado was unusual in that no tornado warning was issued for Quapaw before it struck the town. Meteorologists at the National Weather Service in Tulsa later stated that radar signatures showed no signs of a tornado until it was already over the town and by the time the warning was issued, it had moved into Kansas. The warning for Baxter Springs came only minutes before the tornado struck the city, catching residents off-guard and forcing them to scramble for shelter.
Northpoint–Mayflower–Vilonia–El Paso, Arkansas