Infrastructure and Transportation

Overview

Forecasts consist of a variety of products as follows:

Spring Flood Outlooks:

The first forecasts of the year are the spring flood outlooks which are usually issued in late February and again in late March. Flood outlooks are highly dependent on weather conditions for the ensuing months and therefore outlooks commonly provide estimates of peak flows and river stages for the lower decile, median and upper decile weather conditions. Peak river level forecasts are provided primarily for larger rivers while peak flow forecasts are given for smaller streams. Comparative peaks from past years and bankfull levels and flows are shown to help users assess the implication of the forecasts.

Daily Operational Forecasts and Flood Sheets:

These forecasts are issued when runoff from snowmelt or rainfall is already underway and are based in part on observed streamflows and river levels in headwater areas. They are usually updated on a daily basis when there is significant flooding and include a daily narrative report explaining river conditions and forecasts. Forecasts are based on existing watershed conditions and normal future weather conditions unless otherwise noted. For larger rivers, flood routings are performed. A forecast range is used during the early runoff period to allow for the many unknowns in watershed conditions and river flows and for uncertainties in the forecasting procedures. Anticipated peak stages and dates are shown on flood sheets which are distributed by e-mail and via this web site.

Daily Hydrographs

When flooding is of a serious nature, flood fighters, planners and emergency responders require forecasts of daily river levels. The Forecast Centre prepares hydrographs showing recent observed river levels and predicted levels for the next week 10 days or so. This is a new product which began on the Red River in 2010 but which will be extended to other rivers in future years.