Overland Flood Alerts

Current weather induced overland flood alerts

The Hydrologic Forecast Centre (HFC) issues several categories of flood alert throughout the year including riverine flooding due to snowmelt and rainfall, wind and wave induced shoreline flooding and ice pileup, and rainfall induced overland flooding. This layer demonstrates the location and/or extend of current alerts due to rainfall induced overland flooding. The types are defined below:Overland Flood Warning: A severe weather warning that is issued to alert the public that overland flooding is imminent or occurring in the warned area. Overland flooding is a quick onset of flood conditions, usually occurring after heavy rain that may not be linked to a specific waterway or lake. Rainfall intensity and duration, topography, soil conditions and ground cover are factors impacting overland flooding. Overland flooding can also occur because of a sudden release of water held by an ice jam.Overland Flood Watch: A severe weather watch that is issued when conditions are favourable for overland flooding. Normally issued when significant rainfall is expected in locations with saturated soil.