A look back at 2010's notable precipitation events in the United States using CoCoRaHS (The Community Collaborative, Rain, Hail and Snow Network) Observations

The Community Collaborative Rain, Hail and Snow network (CoCoRaHS) is a nationwide network of backyard weather watchers who measure precipitation manually and report data online. (www.cocorahs.org) While very low-tech in concept, the data from thousands of volunteers reporting every day are helping improve precipitation monitoring locally and nationally.

2010 is the first year with CoCoRaHS participation in all 50 states. Highlights of 2010 largest precipitation events in the country will be presented in chronological order beginning including winter storms in the Mid Atlantic and New England, very large March rains in southern New England, extreme rains in Tennessee in May, abnormally heavy early June rains in Oregon, Comal County, Texas localized extreme rainfall in June 9, Oklahoma extreme rainfall June 14-15, South Texas tropical storm heavy rains July 1-3 and the storms in Milwaukee and Chicago in late July. The largest one-day precipitation amount observed during the first seven months of 2010 was 13.30 inches on May 2nd at Benton County, Tennessee. Maximum daily precipitation nationwide exceeded six inches on 44 days, January - July 2010. An update of storms and heavy precipitation statistics through December 2010 will be provided.

The largest one-day CoCoRaHS precipitation totals in 2010 for each state will be presented and shown as a percent of the all-time observed daily extreme. In the future, this same analysis will be performed each year for historical reference and comparison. As National Weather Service Cooperative data continue to become more quickly accessible, the same analysis will be performed for COOP data and the results compared. A nationwide frequency distribution of daily CoCoRaHS precipitation amounts will also be shown for 2010 and compared with 2009 to show if any significant year to year differences in the distribution of daily precipitation amounts is apparent on a national level.