APRIL SHOWERS, MAY FLOWERS AND JUNE MONSOONS: SPRING PRECIPITATION AND FLOOD HYDROCLIMATOLOGY IN THE HEADWATERS OF THE BLACK WARRIOR RIVER

Spring and early summer precipitation totals during 2003 across Alabama were above average, setting records for June. Traditionally the most active season, springtime precipitation volatility highlights the complexity of Alabama’s flood climatology. This study investigates the hydroclimatology associated with 2003 and other anomalously wet April, May and June months over the past 30 years. Precipitation producing weather patterns were identified for a sample of the wettest spring months to ascertain which of two hypotheses is appropriate. 1) Are events continuously produced by consistent mechanisms that lead to cumulative flooding responses-“eventless”, or 2) Do large events result from abnormal weather patterns punctuating climatic norms- Divergent normal patterns. This seasonal scale understanding was integrated with Sipsey Fork stream stage data and Lewis Smith reservoir water levels to characterize spring flooding mechanisms in the Upper Black Warrior River basin. Preliminary data suggests that maximum values for these variables are mutually exclusive during flood events, not predictably in response to event occurrences. Identifying flood responses in the landscape and resolving the opportunity for sediment transport will help to address the direct, indirect and cumulative impacts of watershed development.