National Weather Service United States Department of Commerce

Winter Storm Impacting Portions of the West

Periods of heavy rain, high elevation snow, and high winds will continue in the Pacific Northwest, Rockies and parts of the Great Basin through the weekend. Minor river flooding, flash flooding, and debris flows will also be possible near recently burned areas in the Pacific Northwest. Strong thunderstorms with heavy downpours will impact the central Gulf to the Southeast into the weekend. Read More >

Flood Return Period Calculator

Though this calculator is worded for the flood event return period it would work for any extreme weather event.

 

Enter the return period (ie..100 year flood)

Percent chance of occurrence

year flood %
Enter the number of years (ie..over the next 10 years)
There is a % chance that a year flood will occur over the next year(s)
year(s)