Preliminary calculations of average storm duration and seasonal precipitation rates for the northeast sector of the united states

Abstract

Regional and seasonal averages of storm duration and precipitation rates are needed as input variables in models aimed at describing precipitation processes relating to acid rain and other problems. Hourly precipitation data for 77 first order weather stations were used to calculate the summer and winter regional average storm duration and average precipitation rates over the northeastern United States. Average storm duration for summer (June–July–August), and winter (December–January–February) seasons considered periods of up to three dry hours in summer storms, and up to 6 dry hours in winter storms to be part of the same storm. Thus, each storm consisted of one or more precipitation periods. The average precipitation event rates for summer and winter storms were calculated. By considering storm duration on an hourly basis, the 3-h summer storm was found to contribute the greatest fraction to total summer precipitation. Similarly, the 26-h winter storm was found to contribute the greatest fraction to winter precipitation. The summer storms typically consisted of one rain event lasting about three hours with rain rates averaging ~ 2.5 mm h −1. The 25-h winter storm averaged about 3 precipitation periods (or rain bands). Each period lasted about seven hours and had an average precipitation rate of 1.0 mmh −1.