File:Mississippi River (MODIS 2018-04-16).jpg

English: High water and heavy smoke are typical of the spring scene along the Mississippi River Valley – but the spring of 2018 brought an overabundance of both of these natural hazards to the region.

On April 12, 2018, the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite acquired a true-color image of the Mississippi River Valley which showed dense smoke pouring across the valley from the west as well as high, muddy waters flowing the length of the Mississippi River.

The Mississippi River has the third largest drainage basin the world, exceeded in size only by the watersheds of the Amazon and Cong Rivers. It drains 41 percent of the 48 contiguous states of the United States, according to the US Army Corps of Engineers. The river basin drains more than 1,245 square miles, including all or parts of 31 states and two Canadian provinces.

During the winter, snowfall builds in the mountains and northern reaches of the basin, from New York state to Montana. As warm weather comes, the snow melt finds its way to the Might Mississippi, typically turning it muddy and cresting at flood levels sometime in late April or May. In 2018, early flooding was reported along the river, especially in the southern reaches. On April 15, 2018, the water height at Arkansas City, Arkansas was 33.71 feet, which is 5.21 feet higher than the date’s normal historic stage of 28.5 feet. The river is still rising, with a forecast of 34.10 feet at that same location on April 16.

The smoke originates from a number of fires west of the Mississippi Valley. The most notable fires are burning in grasslands in Oklahoma, which are parched from drought. Some parts of western Oklahoma have gone more than 185 days without receiving more than one-quarter inch (0.6 cm) of rain. Along with the exceptional drought, sustained winds of up to 35 miles per hour (55 km/h) in some parts of Oklahoma while relative humidity is very low. The combination of hot temperatures (above 90 °F), low humidity, strong sustained winds, and extremely dry conditions have created exceptionally dangerous fire conditions.