Early January 2017 Gulf Coast storm complex

Ice storm

Blizzard

Tornado outbreak

Flood

In early January 2017, a major storm complex developed and produced a tornado outbreak, winter storm, blizzard and ice storm in areas ranging from the Southern United States to New England. Tornadoes impacted areas around the Gulf Coast. Several states, especially Georgia and Tennessee, were hit with heavy rain and snow causing severe floods. As the system moved through the Great Lakes region, heavy rain, ice pellets and heavy snow fell in the entire region. Wintry mix moved through southern Ontario and Quebec had significant snowfall on January 9. Over 60 people were killed in the storm system and its aftermath, which made it one of the deadliest of such systems of 2017 in the United States.

## **Meteorological History**

On January 1, a weak disturbance moved ashore on the West Coast. The disturbance started to move southeastwards into the Southwestern United States early on January 2. Continuing to slowly move east, snow began to fall in the Upper Midwest, dropping up to 5–8 inches (13–20 cm), before rapidly dissipating. As the initial area of low pressure moved over the Gulf Coast, a southwards dip in the jet stream to the west had formed. In response to this, an upper level low developed by evening on January 5. This upper-level low began to track to the north, drawing moisture from the Pacific Ocean and Gulf of Mexico. As it did so, a long cluster of heavy showers and thunderstorms erupted from eastern Louisiana to southwestern North Carolina, which set up a severe flooding event. Some areas picked up to over 1 foot (12 in) of rainfall, triggering several floods.

At the same time, supercells began to appear in Mississippi and western Alabama. One of these produced an EF4 wedge tornado which ripped through parts of Tupelo, Mississippi causing major damage. As the storm complex began to move to the north, more supercells began to pop up with several more tornadoes being reported. By early on January 6, the supercells had begun to merge into a squall line, with tornado reports beginning to diminish, but occasionally a few isolated tornadoes would be produced by the storm until January 7.

While producing severe weather in the Deep South, the storm complex produced heavy snow and blizzard conditions in the southeastern parts of Texas and western Louisiana through January 5–6, as frigid temperatures had spilled south into the area just the previous day before. Strong winds contributed to power outages and blowing and drifting snow. The snowfall continued throughout the majority of January 7, before tapering off near midnight as the storm system began to pull out of the region. In total, the storm complex dumped up to 2 feet (24 in) of snow in the affected areas, which also included Arkansas and northern Louisiana, are very rare occurrence. The storm had also produced a small but significant ice storm in the central parts of Texas, with ice accumulations ranging up to 1 inch (25 mm) in some areas, leading to thousands of power outages.

By January 8, the storm complex had moved into the Mid-Atlantic United States, producing more snow, ice, heavy rain, and severe weather in an area stretching from Louisiana to this region. The upper-level low eventually began to take over as the dominant low, and had begun to make a more east-northeastwards turn. Spreading a swath of 6–12 inches (15–30 cm) from Missouri to Maine, the storm complex continued to accelerate into southern Canada while producing more ice, rain and severe weather as the southern quadrant approached the East Coast. Rain eventually reached areas such Philadelphia and New York City late on January 8, and persisted somewhat into the early morning hours of January 9. At this point, the storm system had already entered Canada, and its circulation was beginning to become elongated. The remnants of the storm eventually dissipated early on January 11.

## **Impact**

### **Tornado outbreak**

On January 5, 2017, the tornado outbreak portion of the storm system, with 31 tornadoes total confirmed, began when 15 tornadoes impacted Mississippi, Alabama, and southern Tennessee that evening; storms almost entirely blanketed Mississippi at one point, and added to the highest tornado death count in the U.S. for the month of January since 1953. An EF3 tornado moved through multiple subdivisions in Whitebury and Columbus, destroying numerous homes and two churches. Nineteen people in Tupelo, Mississippi died as a result of a large and powerful EF4 wedge tornado that destroyed many homes across the city. Additional tornadoes touched down across the Southern United States throughout the next day on January 6 and into January 7. Most of these tornadoes were weak, though several EF2 tornadoes caused considerable damage. More than 65,000 people lost power in the area due to the tornadoes.

Damage from tornadoes in Mississippi alone is estimated at $1.3 billion.

### **Flooding**

The storm system was responsible for heavy rain that caused severe flooding in 13 states, with Kentucky being especially impacted. Parts of the state were hit with over 10 in (0.25 m) of heavy rainfall. At least 14 people died due to the floods in Kentucky alone. In Munfordville, the Green River rose to 70.13 ft (21.4 m), above the preceding record of 69.7 ft (21.2 m) which occurred on November 24, 1959. More than 180 roads, including portions of Interstate 65, US Highway 31 and several bridges were closed. The Kentucky River, near Frankfort, crested 2 ft (0.61 m) above its previous record height, inundating nearby communities. At least 380 homes and 70 businesses were flooded in Franklin County.

Major flooding also occurred in south Alabama, where the Pea River in Elba, Alabama flooded. Most of the rainfall occurred on January 6 when thunderstorms went over the same areas. All in all, a widespread 8-16 inches occurred.

Nine levees were topped—five along the Mississippi River, three along the Missouri River, and one along the Kaskaskia River—though the affected areas were predominantly unpopulated. Large stretches of the Mississippi River were placed on alert due to projected major flooding.

Flash flooding also claimed seven lives in Tennessee, two in Oklahoma, one in Arkansas, and one in Georgia.

### **Winter storm**

The combination of heavy snow, strong winds, and bitterly cold temperatures resulted in blizzard conditions across most of Arkansas, northeastern Louisiana, western Oklahoma and West Texas. Some places in this area had over 1–3 ft (30–91 cm) of snow but also snow drifts up to 12 feet (370 cm) high. In the path of this Louisiana low, a swath of snow and ice impacted the southeastern and northeastern states from Mississippi to New York as the storm system moved northeastward toward the eastern Great Lakes. The storm system spread a wintry mix of snow, sleet and freezing rain to New York State and New England, disrupting travel in the region. At least 1 person in Mississippi, and 4 people in Kentucky died as a direct result of the winter storm system.

## **Notable tornadoes**

### **Tupelo, Mississippi**

   A violent wedge tornado affected nearly 900 homes in Lee County, most of which were in the city of Tupelo. Of these, nearly 500 were destroyed, including a few well-constructed homes that were completely leveled. An additional 10 businesses were impacted, of which one was completely destroyed. Several mobile homes were also destroyed outside of the city. An apartment complex sustained major structural damage, and the Tupelo school was damaged as well. Five people were killed when their vehicles were lofted and thrown long distances from an elevated highway bridge on the I-22 into creeks below, whereas another fourteen deaths occurred throughout the city. 618 people were injured.

### **Corinth, Mississippi**

This significant tornado began in rural Alcorn County, just southwest of the city. The tornado moved northeast, damaging 50 commercial buildings, 23 of which were completely destroyed. Significant damage occurred as a large residential area consisting of hundreds of homes was impacted. The city's high school sustained outward collapse of multiple exterior walls, despite construction up to code being noted at that location. Vehicles were thrown and mangled throughout the city as well. After exiting the city, the tornado struck a forested area, where hundreds of trees were denuded before it dissipated. 4 people were killed, and over 300 were injured.