The lead-time for flood warnings depends on the circumstances of each individual flood event. Because Steuben and Chemung counties are situated in the headwaters of several major drainage systems, the flood warning lead times are generally quite short. All flood forecasts are provided as soon as possible. However, localized flooding problems will have shorter flood warning times than large-scale regional events. Flash flooding can occur suddenly with little or no lead-time.

Travel times of peak flows from upstream gauges to downstream locations are provided below. Rough river stage forecast estimates based on stream gauge levels and stage relation plots are provided with these lead times. Flood forecasts based on precipitation are generally available sooner, with the amount of lead-time dependent on the rate and distribution of the precipitation.

The mission of the Flood Warning Service is to provide data as quickly as possible in order to maximize the time available for emergency response. Meteorological and/or hydrological data are supplied to emergency personnel immediately whenever flooding problems are anticipated or in progress. This raw data is followed by flood forecasts based on simple modeling techniques. More sophisticated flood forecasts prepared by the National Weather Service are distributed as soon as they become available.