A comparison of performance of five rain-gage installations

Abstract

The daily rain, snow, or mixed‐rain‐and‐snow catch by five different rain‐gage installations was measured near Hastings, Nebraska, during the period January 1946 through September 1961. Rain‐gage installations included were a U.S. Weather Bureau standard 8‐inch gage, a weighing‐recording gage, a standard gage on a 6‐foot post, a standard gage equipped with an Alter shield, and a standard gage equipped with a Nipher shield. The shielded gages caught slightly more precipitation (significant at 1 per cent level) than the unshielded gages. When rainstorms were divided into 0.5‐inch increments, the performance of the five different rain gages was not consistent. Some of the differences were statistically significant. The differences in performance of the several gages were so small that they have no practical significance. True precipitation is unknown.

Comparison of Precipitation Catch between Nine Measuring Systems

“…The results from this study agree with those reported by Allis et al (1963) where they found an undercatch of approximately 3% between shielded and unshielded gauges. Hanson (1989) reported an undercatch of approximately 8% for the BELUNSHLD system.…”

“…The DFIR, TRET, BELUNSHLD, and BELSHLD all caught significantly lesser amounts of rain than the WYO as wind speeds increased. These results agree with earlier studies by Allis et al (1963), Hanson (1989), andNeff (1977), which showed that gauge shielding is required for the most accurate measurement of rain.…”

“…In their Nebraska study, Allis et al (1963) found that for snowfall events, unshielded gauges that had been installed according to U.S. Weather Bureau specifications caught approximately 70% of shielded gauges.…”

“…As with snow, the BELUNSHLD had the least catch (82% of WYO), which was significantly less than any of the other gauging systems. Allis et al (1963) reported that an unshielded, standard U.S. Weather Bureau gauge caught approximately 88% of shielded gauges and that the unshielded, standard U.S.…”

“…Undercatch of snowfall by gauges that are not protected naturally, as they are in forest clearings, is one of the major problems in obtaining accurate point measurements. The problem of measuring snowfall under windy conditions has been documented extensively (Kurtyka 1953;Warnick 1953;Weiss and Wilson 1958;Allis et al 1963;Garstka 1964;Israelson 1967;Larson 1971;Neff 1977;Hanson et al 1996). Therefore, in 1985, the Commission for Instruments and Methods of Observation of the World Meteorological Organization recommended that an international study be established to compare current national methods of measuring solid precipitation (snow) (Goodison et al 1989).…”