A Student-Centered Field Project Comparing Nexrad and Rain Gauge Precipitation Values in Mountainous Terrain

Abstract

A team of undergraduate geoscience students compared Next Generation Weather Radar (NEXRAD) estimates of storm total precipitation to measurements from a network of 20 rain gauges. Student researchers gained valuable experience in field data collection, global positioning systems (GPS), geographic information systems (GIS), Internet data access and downloading, computer graphic analysis, descriptive statistics, and conference presentation. The project emphasized problem-solving techniques, positive interdependence and individual accountability.The study evaluated 31 storms delivering >= 0.30 inches total precipitation to one or more gauges in the 51.8 km2 Burd Run watershed, which drains a low mountainous area of south-central Pennsylvania. Rain gauge measurements fell within the corresponding range of radar estimates in less than half (46.8%) of all cases. Departures between rain gauge and radar estimates were more common for large storms (total precipitation >= 1.00 in at one or more gauges) than for smaller storms (0.30 - 0.99 in). Students explored the environmental reasons for data departures.SI units are used throughout this paper except in the case of precipitation measurements. We maintain the National Weather Service standard of using English units (inches) when discussing precipitation values.