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Unseasonably cold temperatures caused record late freezes from June 3'd through June 6th across much of the west, with crop losses extending as far south as Kansas. As the cold high-pressure system moved eastward by the 8th, low pressure to the west brought a strong flow of moisture from the south and a return of increased thunderstorm activity. Rainfall amounts of 1 to 2.5 inches were reported over parts of Nebraska and Iowa on the 11th. The Nishnabotna River and the Missouri River below Nebraska City rose above flood stage by the 12th. This helped set the stage for more serious flooding in watersheds near the Missouri River in the days to come. , Very heavy rains developed over eastern Nebraska and western Iowa as a surface low pressure system moved from northeast Colorado to southwest Iowa on the night of Saturday June 13'h - 14th, along a slow moving warm front which was lihing northward from Kansas and Missouri. The low-pressure system became stationary over southwest Iowa, setting the stage for record setting rainfall and flooding in the Nishnabotna River basin. Wrap-around subtropical moisture from the Gulf of Mexico fed persistent rainstorms over western and central Iowa resulting in extremely large rainfall totals, The rainfall rates were moderate; only about an inch per hour, but the stationary nature of the parent storm allowed the rainfall to continue for 1 2 to 14 hours at that rate in some portions of the upper Nishnabotna River basin. The heaviest rainfalls occurred in Cass County and adjacent portions of Pottawattamie and Montgomery counties between midnight on June 13th through mid-afternoon on the 14th. By the time it was over, a new official 1 - day rainfall total for the state of Iowa 113.20 inches) had been set at radio station KJAN in Atlantic, Iowa, eclipsing a single day rainfall record set back in the 1890's. Other unofficial rainfall reports gathered during a subsequent bucket survey, ranged up to 15.25 inches in Lewis, Iowa. In the four days that followed, stream stage records were set at Red Oak and at Hamburg, Iowa, and elsewhere in the basin, as the flood crest made its way downstream towards Hamburg. The peak discharge at Hamburg was estimated to be between 60,000 and 70,000 cfs, based upon current rating curves. The USGS measured nearly 90,000 cfs upstream at Riverton, Iowa, on June 16th, when the flood was near its crest, so the final discharge value may be revised upward. Numerous levees failed from the headwaters to the mouth of the Nishnabotna River, inundating towns, farmland and roads. , , Stages on the Missouri River rose as well, during the Nishnabotna River flood. At the time of the crest on the Nishnabotna on June 17th, the Missouri River 14