It has been a very active week with extreme weather in the Central US, providing ample opportunity to showcase more of MetStorm™’s unique analitics. Today’s post will highlight the record precipitation Wednesday through Thursday in Eastern Nebraska with the MetStorm™ Average Recurrence Interval Analytic. The record rainfall and significant rainfall rates caused widespread flooding through Eastern Nebraska, according to the Hastings, NE WFO. A narrow band of precipitation oriented southwest-to-northeast moved northeastward, causing the same areas to be overwhelmed with precipitation over a short amount of time. In addition to the heavy precipitation, this same event also produced several tornadoes.

Average Recurrence Interval (ARI) – also known as a return period – is a representation of precipitation amount per unit time as average number of years (climatologically) between equivalent events for a specific locations. It helps convey the rareness of rainfall and high impact storms. Here is the ARI map for the Hebron, Nebraska storm (updated 5/12/2015):

This storm has an impressive maximum ARI of over 1000 years for a 6-hour duration. MesoWest station Big Sandy Creek at Alexandria, NE, recorded 9.71″ in just 6-hours, an example of just how much rain needs to fall for this high of an ARI in this location to occur. This event is climatologically significant as this map suggests, which indicates it is a rare phenomenon for over 9 inches of rain to fall over just 6 hours in this location.

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Thanks for visiting our blog, we hope you enjoyed today’s post! Come back soon for updates to these latest MetStorm™ analyses and for more posts to come!

-MetStat Team