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Marine and Coastal Impacts from Imelda; Unsettled Weather in the West

Swells and high surf from both Imelda and Humberto are expected to bring dangerous marine conditions and rip currents to much of the East Coast over the next several days. A series of Pacific frontal systems will bring waves of showers and thunderstorms to portions of northern California and the Pacific Northwest through midweek. Read More >

Overview

From the evening of May 20th through mid afternoon on May 21st, several waves of thunderstorms produced tornadoes, damaging winds with gusts up to 90 mph, hail up to tennis-ball size, and extremely heavy rainfall, which resulted in considerable flash flooding and river flooding.

Six tornadoes (5 EF0 and 1 EF1) occurred with a fast-moving line of thunderstorms that moved through eastern Nebraska and southwest Iowa during the early morning hours on the 21st. An additional 4 tornadoes occurred with a second round of thunderstorms (supercells) that formed over far eastern Nebraska and tracked through southwest Iowa during the late morning and early afternoon hours on the 21st. 

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Radar loop from 4 PM on May 20th through 3 PM on May 21st
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