During the evening hours of February 5, 2008, a short-lived but violent tornado tracked through portions of Madison County, in the U.S. state of Tennessee. The tornado caused significant damage in the northern suburbs of the city of Jackson, and occurred as part of a deadly tornado outbreak, while the 2008 Super Tuesday primary elections were held throughout the nation. This powerful tornado was among the five EF4 tornadoes rated as such on the Enhanced Fujita scale that outbreak, and was one of two to occur in Tennessee on February 5, with the other one occurring over in Hardin County.

Along its 8-minute lifespan, the tornado, colloquially named the Union or Union University tornado, caused extensive damage throughout the northern sections of Jackson, most notably at Union University, where the tornado caused heavy damage to several campus dorms and other parts of the university. Elsewhere along its damage path, many homes and businesses were damaged or destroyed. Despite the tornado tracking through densely populated areas, only 51 people were injured and no deaths were reported.

Meteorological synopsis Episode narrative

One day earlier at 7:00 p.m. CST (19:00 UTC) on February 4, the NOAA Storm Prediction Center (SPC) issued a widespread level 2/5 slight risk across the central United States, from central Texas to western Indiana. Accompanying it was a 5% tornado risk that spanned from northeastern Texas, eastern Oklahoma, western and northern Arkansas, and southern Missouri. During the overnight hours at 12:00 a.m. CST (06:00 UTC) on February 5, the SPC drastically took measures, and issued a large level 4/5 moderate risk for states within the Mississippi River Valley. A Public Severe Weather Outlook (PWO) was in effect due to the forecast of an outbreak of severe thunderstorms, widespread and damaging winds, and a few but strong tornadoes in an area from northern Louisiana, to southern Illinois and Indiana. Large 15% hatched, 45% and 30% risks for tornadoes, damaging winds and large hail encompassed portions of mainly Arkansas, Louisiana, Mississippi, Tennessee and Kentucky.

A strong, upper-level trough was transforming in the Four Corners region, and forecasted to lift northeastwards towards the southern Great Plains and mid-Mississippi River Valley regions. Mid and upper level jet streaks strengthened downstream from the Ark-La-Tex, towards the lower Ohio River Valley area. Near the surface, a low-pressure area in the Red River Valley, over central Oklahoma and north-central Texas was expected to deepen in nature whilst maturing to the northeast into north-central Arkansas, and southern Ohio later.

A nearby dry line over the southern Great Plains that accompanied the low area, was noted by the forecasters to evolve into a Pacific cold front as it headed east towards Arkansas and Louisiana. At the same time, a second but more potent cold front surged southeastwards from western Texas and central Oklahoma, taking over the Pacific cold front after at midnight in the Mississippi River Valley.

Around seven hours later at 7:00 a.m. CST (13:00 UTC) on February 5, the SPC increased the general categorical outlooks to a level 5/5 "high risk" of 30% chances of tornadoes for eastern Arkansas, northwestern Mississippi and extreme southwestern Tennessee. The environment was conducive enough for potentially long-lived tornadic supercells, within the Midsouth region of the contiguous United States. Deep, upper-level troughs, and associated extreme mid and upper-level wind fields in excess of bolstered the severe threat of storms from the southern Great Plains, towards the northern Gulf states and Ohio River Valley later into the day.

Widespread, elevated storms increased in prevalence in the morning, due to the accompanying ejecting lower amplitude trough over northern Texas and most of Oklahoma. Additional thunderstorms persisted and began to backbuild in a large region of near-surface warm advection and enhanced lift, located near the cold front that moved southwards across the Ohio River Valley. Surface low area developed over far northern Texas, and expected to deepen as it lifted northeastwards along the surface front into northern Arkansas and southern Indiana later. The upper storm system ejected the dry line/north-south oriented surface trough eastwards, across the southern Great Plains in the morning, to the lower and mid-Mississippi River Valleys. Later, the front that followed the shortwave trough moved into the upper Midwest, was expected to stall and lift marginally north tonight as a warm front, in response to the intensifying surface low area over the Ohio River Valley. Persistent moisture encompassed a broad region within the warm sector from eastern Texas to the Tennessee River Valley, as surface dew points rose into the 60° degree Fahrenheit (15.5° Celsius) range.

Event narrative At 10:30 a.m. CST (16:30 UTC) on the day of the event, the SPC situated the high risk, 30% tornado outlook to the Missouri Bootheel and extreme extreme Kentucky, with most of western Tennessee also encompassed under the hazardous risk. At 2:00 p.m. CST (20:00 UTC) at midday, the latest visible satellite imagery showcased the leading edge of the area of large scale lift, began to interact with the dry line over Texas. The region of where Cumulonimbus clouds were growing expanded to the Interstate 35 corridor. East of the dry line in southeastern Oklahoma, abundant sunshine was noted in a large area in that state. The unstable air mass heated up into the 70°F (21.1°C) range. Atmospheric sounding data from earlier at 12:00 p.m. CST (18:00 UTC) in the lower Mississippi River, towards north of the Gulf of Mexico suggested the strong capping inversion weakened, and become negligent as adjacent lift gets more prominent. A powerful, jet streak ejected into region spanning the Ark-La-Tex to western Kentucky and Tennessee. Extreme vertical shear profiles bolstered the storm potential. Despite a mode for discrete storms being highly anticipated, storm mergers and convective outflow gave signs to a very dangerous and damaging wind threat. Alongside the wind threat, large hail was more than likely to occur in supercells across the western half of the high risk outlook.

Tornado summary Preceding EF3 tornado Prior to the Union tornado, a long-track, and deadly EF3 tornado touched down in Fayette County, Tennessee, near the unincorporated community of Yum Yum at 6:21 p.m. CST (00:21 UTC). Right after formation, the tornado struck a residence at EF3 intensity on Yum Yum Road, killing a man who was sitting inside his vehicle within a shed. The truck was moved at least from its original spot and severely damaged, along with other vehicles. The tornado entered Haywood County and barreled towards Dancyville and Hillville at EF2 intensity. Two homes in Dancyville were both heavily damaged or destroyed, alongside a church and trees that were uprooted. In Hillville, many structures, including a convenience store, suffered varying levels of damage before the tornado left for Madison County. Now passing by Denmark, the tornado traversed the landscape, before impacting Huntersville at EF3 strength.

Two homes out of multiple in the community, including one on Huntersville-Denmark Road, were leveled and had both of their elderly occupants killed. The St. John #2 Baptist Church also suffered extensive damage, with a bus thrown hundreds of feet. On Interstate 40, numerous vehicles were blown off the road, such as one car that was thrown into a farm field, before the tornado dissipated at 6:54 p.m. CST (00:54 UTC). This intense and lethal tornado traveled for and was up to wide. Three elderly people were killed and 14 others were injured.The National Oceanic and Atmospheric Administration's finalized damage survey by county:

Union EF4 tornado

The tornado first touched down at 6:59 p.m. CST (00:59 UTC) at Union University near the US 45 Bypass, before inflicting significant damage to various structures on the campus. Quickly reaching EF4 intensity with maximum estimated wind speeds of , the tornado collapsed two dormitories, with 80% of the dorms being extensively damaged or destroyed. Students followed the university's emergency plan and sought shelter in bathrooms and interior rooms as the tornado continued to inflict damage. Around 1,200 students were in the campus dorms at the time, with 11 being trapped under the debris and 51 sustaining injuries.

The tornado then impacted 17 academic buildings, with three suffering severe damage. Hundreds of vehicles in the campus parking lots were damaged or destroyed by the tornado before it crossed the US 45 Bypass and damaged several banks and other businesses. The tornado then struck the Regional Hospital and several nearby doctors' offices before continuing into northern portions of Jackson, where it tracked across several subdivisions.

The tornado struck the subdivisions of Chapel Creek, Indian Hills, and Wyndhurst, and also inflicted damage to the Jackson Oaks Senior Living Complex before continuing to move northeastward. The tornado then impacted the Northside High School in the Oak Hill region and tracked across the Walnut Trace subdivision. The tornado crossed Old Medina Road and continued to damage homes, causing EF3 damage with estimated wind speeds of near the Christmasville Road/Ashport Road intersection where Madison County Fire Station 11 was destroyed. The station's fire engine, and water, brush, and pumper trucks sustained damage, and various homes in the area were also impacted. The tornado then quickly dissipated at 7:07 p.m. CST (12:07 UTC) after being on the ground for .

The Union tornado was the third of a handful of violent tornadoes (F4/EF4+ on the Fujita and Enhanced Fujita scales) to strike the Jackson area in 10 years. Prior to the 2008 storm, the city was struck on May 4, 2003 and January 17, 1999.

Aftermath

Damage

Along its track, the tornado completely destroyed 70 structures, with over 500 others sustaining damage. At Union University, two dormitories completely collapsed and several others were impacted, with 80% of the dorms being destroyed or damaged, with the women's dormitories being more heavily impacted. An additional 17 buildings on the campus were damaged, with three suffering from major damage. The roof of the Jennings Hall was torn away, and several hundred vehicles in the campus parking lots were overturned and destroyed. Around $40 million (2008 USD) in damages was inflicted at Union University alone.

The tornado damaged numerous businesses and institutions, including banks, doctors' offices, and a hospital. Several subdivisions were also impacted, with numerous homes suffering damage. The Jackson Oaks Senior Living Complex was heavily damaged, and a store near North Side High School was destroyed. Signs off of I-40 were carried five miles and deposited in the back of a property along Ashport Road. Madison County Fire Station 11 was demolished, and several of its vehicles also sustained damage. In all, the tornado inflicted $100 million in damages.

Recovery efforts Directly following the tornado, it was discovered that 11 students were trapped in the debris from the Union University dormitories. The Madison County fire chief ordered that 100 body bags be brought to the scene due to the dorms being heavily impacted and the large amount of students on campus. However, no students were killed, though dozens were injured, some seriously. Union University President Dr. David Dockery described the tornado as one of the worst natural disasters to happen at a college campus in United States history. On the night of February 6, Tennessee National Guard troops guarded the campus, securing the damaged dorms and academic buildings before assisting students in finding belongings the following morning.