Technical Paper 40 Precipitation Frequency raster surfaces for the 2- to 100-year return period, 24-hour duration storms for the continental United States

This fileset consists of raster surfaces for the 2-year to 100-year return period storms described in the Technical Paper 40: Precipitation-Frequency Atlas of the United States (TP40). TP40 is a collection of isopluvial maps from which precipitation depth for different return period and storm durations. Using QGIS, a open-source geographical information systems software, the maps in this fileset were created by first georeferencing the digitalized physical maps available publicly via the NOAA's Hydrometeorological Design Studies Center. For the 24-hour duration, and each return period aforementioned, the isopluvial contours were interpolated using inverse distance weighting algorithm.