92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Thursday, 26 January 2012: 1:30 PM
A 10-Year Survey of Extreme Rainfall on Multiple Timescales in the Central and Eastern United States
Room 352 (New Orleans Convention Center )
Russ S. Schumacher, Colorado State University, Fort Collins, CO; and S. N. Stevenson

The NCEP Stage IV multi-sensor precipitation analyses are used to objectively identify instances of heavy precipitation in the central and eastern United States during the years 2002--2011. The analyzed precipitation amounts are compared against recurrence interval thresholds representing a 1% and 2% probability of occurrence in a given year, for 1-hour, 6-hour, and 24-hour accumulations.

In general, the distributions of events are consistent with past research on heavy local rainfall, with maxima occurring in June, July and August. There is also a maximum in 24-hour rainfall points in September that is associated with landfalling tropical cyclones. Hourly heavy rainfall occurs most often from the late evening through the night, and least often in the late morning and early afternoon. This method for identifying heavy rainfall also emphasizes the magnitude of some recent notable events, such as the May 2010 Nashville, Tennessee flood, the August 2007 flood in Minnesota and Wisconsin, and the July 2011 rainfall in eastern Iowa and western Illinois. The meteorological characteristics of these and other notable events will be discussed. Finally, information for other researchers about accessing this database of heavy rainfall events will be presented.

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