Using Synoptic Climatology to Define Representative Discharge Events

Hydroclimatic modellers presently have no well-established methodology either to identify representative scenarios or to confirm that their model output agrees with observation. To fill this gap, this research presents a synoptic climatological framework that distinguishes typical storm systems associated with above-average discharge from Pennsylvania's Susquehanna River basin (SRB) and establishes the characteristic hydrographic responses to those systems. To determine the effect of basin scale on the results, these responses are stratified by sub-basin size. The results show that those storm systems tapping into Atlantic Ocean moisture usually produce above-average discharge in the SRB. Hydrographic responses vary with the storm trajectory and type. However, within a sub-basin scale and for any storm type, these hydrographic responses are the same from sub-basin to sub-basin. Thus, almost any basin is representative of its scale. Additional findings suggest that conventional single-day synoptic types are inappropriate for many types of research. Still, it is concluded that a synoptic climatological framework can be valuable for defining model scenarios and confirming model experiments.