Nebraska, located in the heart of the Great Plains, is highly susceptible to natural hazards. Its geographic location acts as a weather funnel where cold, dry air from the north frequently collides with warm, moist air moving up from the Gulf of Mexico. This atmospheric conflict creates an environment primed for extreme weather events throughout the year, ranging from destructive summer storms to deep winter freezes.
Severe Convective Weather
Nebraska lies within “Tornado Alley,” characterized by a high frequency of tornadic activity. The most intense events are often generated by supercell thunderstorms, which are powerful, long-lived storms defined by a deep, persistent rotating updraft called a mesocyclone. These storms can produce tornadoes with wind speeds exceeding 135 miles per hour. Severe thunderstorms are also frequent sources of damaging straight-line winds and large hail. A destructive, widespread wind event known as a derecho occurs when a line of intense, fast-moving thunderstorms produces wind damage extending over 250 miles, often involving gusts over 75 miles per hour and causing extensive damage to infrastructure and crops.
Hydrological Extremes: Flooding and Drought
Nebraska experiences hazards ranging from devastating floods to chronic drought conditions. Major riverine flooding often occurs along the Missouri and Platte rivers. Floods are sometimes exacerbated by a combination of intense rainfall and unseasonably warm temperatures rapidly melting winter snowpack. This sudden runoff saturates frozen ground, leading to historic crests and widespread damage. Massive ice chunks, known as ice jams, further compound the issue by striking and damaging bridges, dams, and levees.
Drought is a cyclical, long-term threat that significantly impacts the state’s $28 billion agricultural sector. Dryland farmers, who rely solely on rainfall, are particularly vulnerable, sometimes experiencing crop yield reductions of 50 to 75% during severe drought years. Ranchers also face hardship, as hay prices increase and dry pastures force them into early culling or supplemental feeding of their cattle. Drought conditions can also lead to low water flows in major rivers, impacting utility water intakes.
Winter Weather Hazards
Cold-season hazards in Nebraska are dominated by blizzards, ice storms, and dangerous wind chill. A blizzard warning is issued when winds reach 35 miles per hour or greater, with visibility dropping significantly for at least three hours, making travel nearly impossible. Average seasonal snowfall across the state ranges from 20 to 40 inches, with the heaviest amounts often falling in the northern Panhandle. Ice storms, caused by freezing rain, coat surfaces with ice, leading to downed power lines and extended outages. Extreme cold poses a severe threat, with wind chill values often dropping low enough to cause frostbite on exposed skin in less than 30 minutes.
Low-Frequency and Geological Risks
Risks that occur less frequently but are still present include wildfires and seismic activity. Wildfires are a persistent threat, especially in the western Sandhills region, where dry lightning and drought conditions can ignite expansive prairie and grassland fires. The combination of fire and prolonged drought raises concerns about the potential for sand dunes to become destabilized. Geologically, Nebraska is classified as having a very low seismic hazard, meaning there is less than a 2% chance of experiencing damaging earthquake shaking in a 50-year period. Despite this low risk, small, localized clusters of low-magnitude earthquakes have been recorded, such as a recent cluster of events in Custer County.