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Back-to-Back Pacific Storms to Impact the West Coast; Heavy Snow in the Central Appalachians

Back-to-back powerful Pacific storm systems to impact the Pacific Northwest and northern California through the end of this week with heavy rain, flooding, strong winds, and higher elevation mountain snow. A strong, long-duration atmospheric river will accompany the Pacific storms, bringing excessive rainfall and flash flooding to southwest Oregon and northwest California through the week. 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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