Comparison of normal and below normal July precipitation patterns in central Iowa

✍ Scribed by White, Gary R. ;Vaughan, Harry C.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Weight: 451 KB
• Volume: 2
• Category: Article
• ISSN: 2314-6214
• DOI: 10.1002/joc.3370020403

✦ Synopsis

Abstract

Previous discussions of wet, dry and normal years in Iowa have been related primarily to the departure of rainfall from a climatological average. Rainfall during the month of July is examined because of its importance on the local cash crop, maize. The first section of the paper deals with the variability of areal precipitation patterns within the central Iowa climatological network (1000 km^2^/gauge) for the years 1930‐1978. Results of this study seemed to indicate that examination of a fine‐grid rain gauge network (1‐64 km2/gauge) was needed. Weather radar data also were used to provide a better data base to study the size and variability of July precipitation areas. In the second section, July 1976 (dry) and July 1977 (normal) were chosen to provide a comparision of precipitation patterns between a dry and normal precipitation year. The results show that, during a dry year (40 per cent below normal), there are nearly the same number of days with rain occurring as in a normal year. The most important factor in the comparison of the two years is that the size and number of individual precipitation echoes are both about 40 per cent less during 1976 than in 1977.