A study of snowfall from coincident surface and space measurements

Over the period of January 10 to the 18 2003, a student research team obtained snowfall measurements and weather data at Storm Peak Laboratory (SPL) in the vicinity of Steamboat Springs Colorado. These measurements were obtained in sequential collections of every three hours around the clock. The team registered four snowfall events with different water-equivalent precipitation amounts. Three-hour composite images from the Tropical Rainfall Measuring Mission (TRMM) home-page were downloaded and precipitation amounts were estimated to compare with the precipitation amounts determined from surface measurements. Out of 12 snowfall measurements at SPL with coincident data from TRMM, 7 measurements by TRMM reported snowfall (58% detection). The analyses of these measurements for the "SPL pixel" showed a poor correlation (R = 0.58) for the surface snowfall measurements and the precipitation amounts estimated from the satellite were significantly larger than the surface measurements. The discrepancies between the space-borne and surface measurements are expected to be improved using measurements from space-borne microwave imagers.