OBSERVATION AND ANALYSIS OF MIDWESTERN RAIN RATES

A prototype meteorological station has been established in Iowa City f or the measurement of surface meteorological parameters with accuracy and resolution sufficient to allow for modern dimensional and scaling analyses. The sensor characteristics are presented and an initial anal ysis of the rain-rate time series of seven storms with high quality da ta yielded the following results: (a) scaling exists for the short tim escales, which in most cases extended up to a few tens of seconds, and it does not extend to the longer timescales for all the storms, and ( b) four of the seven storms exhibit hyperbolic behavior of the exceeda nce probability distributions, with the value of the associated expone nt in most cases being near 2 but higher than the values obtained prev iously from radar and conventional rain gauge data. Analysis of the ti me series of concurrent surface meteorological variables for a particu lar spring storm shows that there is interdependence of the time serie s with an implied reduction of the dimension of the state space of loc al surface rainfall.