EF4 Tornado — Pemiscot, Missouri

2021-12-10 · near Samford, Pemiscot, Missouri

Event narrative

The tornado seemed to reach its peak intensity as it moved into Pemiscot County, Missouri from Dunklin County, Missouri. A home along County Road 454 was substantially damaged. Further northeast, near Highway J and County Road 407, two homes were completely destroyed with debris carried off to the northeast. A fatality occurred in one of these homes. Several vehicles, including semi-tractor-trailers, were blown off of the road as the tornado crossed Interstates 55 and 155, resulting in another fatality. An indirect fatality occurred when a vehicle struck a downed utility pole. Aerial and satellite imagery showed ground scouring marks in this area across the Mississippi River. The tornado then moved into Lake County, Tennessee. Peak winds in Pemiscot County were estimated at 170 mph.

Wider weather episode

December 10, 2021, was unseasonably warm over the region. Temperatures broke several long-standing records. Memphis hit 80F which broke a 103-year-old high-temperature record.

A strong upper-level trough was approaching from the west, providing strong lift within the unseasonably warm and unstable air mass. MLCAPE reached the 1500-2000 J/kg range by 6 PM. The wind field was impressive with plenty of vertical wind shear needed for organized thunderstorms. Effective 0-1 km storm-relative helicity values ranged from 300-400 m2/s2 with effective bulk shear values of 70 knots - more than sufficient to support discrete supercells in the warm sector ahead of the cold front.

The first supercell developed in central Arkansas and tracked into northeast Arkansas producing a few weak tornadoes initially before intensifying across eastern Craighead and Mississippi Counties and killing two people. The tornado eventually strengthened into an EF-4 while moving through the Missouri Bootheel, resulting in 2 direct and one indirect fatality in Pemiscot County. The tornado then tracked across the Mississippi River into northwest Tennessee, producing an additional 4 fatalities near Reelfoot Lake. This tornado lifted for a brief time in Obion County, reorganized, and then moved into Kentucky. All told, the mesocyclone tracked for over 300 miles and was producing tornadoes for over 250 miles. This storm was responsible for at least 9 fatalities and many injuries in the NWS Memphis CWA along with millions of dollars of damage.

As the initial supercell was crossing the state line into Kentucky, a string of supercells was moving into eastern Arkansas. A few brief tornadoes produced minor damage near Cash in western Craighead County and in the Fisher area of western Poinsett County. As the dominant supercell moved into eastern Poinsett County, the mesocyclone quickly intensified and the storm produced an EF-2 tornado in Trumann with several injuries and widespread damage.

A new supercell developed in Mississippi County causing straight-line wind damage initially. This supercell intensified as it crossed the Mississippi River and produced another long-track tornado starting in Dyer County, Tennessee. This tornado tracked east-northeast across northwest Tennessee into Henry County, and eventually into Kentucky. This tornado was rated EF-3 and resulted in several injuries with Kenton and Dresden, Tennessee being the hardest hit.

The convection eventually evolved into a QLCS as it moved east. A mesovortex developed south of I-40 near Jackson that resulted in 3 tornadoes across eastern Madison, Henderson, and Decatur Counties including an EF-2. Non-tornadic storms moved across the Memphis metropolitan area, producing straight-line wind damage as a mesovortex moved through the city. A fatality was reported in Shelby County after a large tree fell on a home in South Memphis. Later that night, an EF-1 tornado occurred in Prentiss County before the severe weather threat began to wind down around 6 AM on December 11, 2021.

In total, there were 18 tornadoes across the NWS Memphis CWA. Along with tornadoes, several incidents of wind damage and minor flash flooding also occurred.

View location on OpenStreetMap → (36.0840, -89.9600)

Source: NOAA Storm Events Database, event_id 997130. Narrative written by the NWS forecast office that issued the report.