Tornadoes Kill 16 in Arkansas, Oklahoma, and Iowa

The quiet 2014 severe weather season turned grimly violent over the weekend, as multiple deadly tornadoes ended our record-long start to a year without a tornado fatality. Media reports put Sunday's death toll at 16, with 164of deaths in Arkansas, one in Iowa, and one in Oklahoma. Hardest-hit were Mayflower and Vilonia, Arkansas, located about fifteen miles north of Little Rock. A large and powerful tornado that had been on the ground nearly an hour carved through the region near sunset, killing at least ten people. Damage photos appeared to show at least EF-3 type damage, and there was a report from relayed from amateur radio to the NWS that two homes in Vilonia had been “wiped clean to the foundation”, which would imply higher than EF-3 damage. There has been only one known F5 tornado in Arkansas history, on April 10, 1929. Vilonia was hit just three years ago, on April 25, 2011, by an EF-2 tornado that killed four people.


Figure 1. Travel trailers and motor homes are piled on top of each other at Mayflower RV in Mayflower, Ark., Sunday, April 27, 2014. (AP Photo/Danny Johnston)


Figure 2. Radar reflectivity image of the supercell thunderstorm that hit Vilonia, Arkansas at 00:52 UTC (7:52 pm CDT) on April 27, 2014. Vilonia’s position is denoted by the circle with a “+“ in it, and lies underneath a classic hook-shaped echo commonly seen from strong tornadoes.


Figure 3. Doppler velocity image of the supercell thunderstorm that hit Vilonia, Arkansas tornado. Note the clump of green colors lying right next to orange and red colors over Vilonia, showing that winds moving both towards the radar and away from the radar were located in close proximity to each other, the signature of a rotating mesocyclone in a severe thunderstorm capable of spawning a strong tornado.

The Arkansas Department of Emergency Management said three people also died in Arkansas’ Pulaski County and one in White County from tornadoes on Sunday. NOAA's Storm Prediction Center (SPC) had put much of Arkansas in their “High Risk” area for potential severe weather yesterday. It was the first “High Risk” outlook issued by SPC in 2014. According to The Encyclopedia of Arkansas History and Culture, the deadliest outbreak in Arkansas history occurred on March 21, 1952, when 112 people lost their lives. The most deadly recent outbreak was on March 1, 1997, which resulted in 25 Arkansas fatalities.

Outside of Arkansas, a tornado hit Quapaw, OK on Sunday, killing one person and destroying the fire station. In Kansas, the governor declared a state of emergency for Baxter Springs, where a tornado destroyed 70 homes and 20 businesses. In all, SPC logged 31 preliminary tornado reports from five states on Sunday, 107 reports of damaging winds, and 118 reports of hail. Also on Sunday, an 11-month old died from injuries suffered during a tornado on Friday in Chowan County, North Carolina. It was the first U.S. tornado death of 2014.


Figure 4. Severe weather outlook for Monday, April 28, 2014, as issued on Monday by NOAA's Storm Prediction Center.

Tornado and severe weather outbreak continues on Monday and Tuesday
The strong, slow-moving low pressure system that brought this weekend’s deadly tornadoes will spawn spawn more supercell thunderstorms capable of generating large hail, damaging winds, and a few strong tornadoes on Monday. NOAA's Storm Prediction Center (SPC) has issued their "Moderate Risk" forecast of severe weather over much of Mississippi, central and northern Alabama and west and central Tennessee. The risk of severe weather will diminish on Tuesday, but most of the Southeast U.S. will be in SPC’s “Slight Risk” region for severe weather. Wednesday will see additional severe thunderstorms along the Southeast U.S. coast, and the severe threat will finally end Wednesday night as the storm responsible moves off the coast.


Video 1. Damage from the Mayflower/Vilonia, Arkansas tornado taken from a drone operated by storm chaser Brian Emfinger of KATV.

Jeff Masters