Regions of Nebraska

Two out of five Nebraskans live in these four counties, on the bluffs where the Missouri turns. It is the wettest, most wooded corner of the state and the one that takes the full Gulf feed: the June derechos arrive here after crossing 400 miles of open ground, and the Papillion Creek watershed floods faster than anything else in Nebraska because so much of it is now roof and pavement.

Lincoln sits in the Salt Valley, on the saline wetlands that gave the city its first industry and still hold the rarest habitat in the state. It is far enough from the Missouri to lose Omaha's humidity and far enough east to keep the corn-belt rainfall, which puts it squarely on the line where Nebraska's spring supercells stop being discrete and start being a line.

This is the corner of Nebraska with the most water and the most tornadoes per square mile. The Elkhorn drains it south and the Missouri closes it on the north and east, and the 2014 Pilger tornadoes — two EF4s on the ground at once, four miles apart — happened in the middle of it. The Bow Creek hills north of Wayne are the roughest ground east of the Sandhills.

Half a million sandhill cranes stage on eighty miles of the Platte here every March — the largest concentration of cranes on earth, and the reason the river's braided channels are managed the way they are. It is also the middle of the I-80 corridor, where the corn stops being rainfed and starts being irrigated, and the ground north into Custer County climbs out of the valley into the loess canyons.

Grand Island took the worst tornado night in Nebraska's record: seven tornadoes on 3 June 1980, several of them anticyclonic, turning through the city for three hours. The ground north of it is the Loup country — three rivers off the Sandhills running southeast through sandy tableland, the transition between the irrigated Platte valley and the grass.

The first homestead in the country was claimed just west of Beatrice, and this is still the most thoroughly farmed corner of Nebraska — deep loess, forty inches of rain in a wet year, and the Big Blue and Nemaha both prone to flash flooding off it. It is the part of the state that behaves least like the plains and most like Missouri across the river.

The Panhandle is a different state meteorologically: 4,000 feet, semi-arid, on Mountain time, and close enough to the Laramies that its summer storms are built on upslope flow rather than the dryline. The Pine Ridge escarpment north of Alliance is the only forested ground in Nebraska, and it burns — the 2012 fires took 75,000 acres of it.

The two Plattes join at North Platte, and so do the two climates: the North Platte comes off the Wyoming snowpack and the South Platte off the Colorado Front Range, and the ground between them is the driest farmed country in Nebraska. Bailey Yard is the largest railroad classification yard in the world, and winter forecasts here are written for it.

The 1935 Republican River flood is still the worst natural disaster in Nebraska's history — a wall of water off a stalled thunderstorm complex that killed more than a hundred people in a night — and the reservoirs above Alma and Franklin exist because of it. The country is flat, deep-soiled and almost entirely irrigated, and it sits under the dryline more often than anywhere else in eastern Nebraska.

Fremont sits in the angle where the Elkhorn comes into the Platte, which is why the March 2019 flood cut the town off entirely — a bomb cyclone onto frozen ground and a foot of snowpack, with ice jams on both rivers at once. It is the tightest flood geometry in Nebraska and the reason the lower Platte gauges are watched the way they are.

The Loup comes into the Platte at Columbus, and the canal system that leaves the river above town has been generating power since 1936. This is the hinge of the state — the last of the corn-belt rainfall to the east, the first of the irrigated tableland to the west — and the storms that organise over the Loups arrive here already mature.

Twenty thousand square miles of sand held down by grass, the largest dune field in the western hemisphere and the emptiest place in the eastern half of the country: fourteen counties and 28,000 people, less than one Omaha suburb. The Ogallala comes to the surface here in a thousand lakes and marshes, the Niobrara cuts the northern edge into canyon, and there is no Interstate and almost no pavement.