Canadian Wildland Fire Information System

Monthly and Seasonal Forecasts

Forecast Severity Anomaly

The monthly and seasonal forecast maps present predictions of fire weather severity based on the monthly and seasonal severity rating. Predictions are based on Environment Canada's monthly and seasonal forecasts, information contained in the Canadian Wildland Fire Information System (CWFIS), and advice provided by provincial agencies.

Before and during the fire season, monthly forecast maps are generated at the beginning of each month (i.e., April to September). The first 4 months from the present are based on a 40-member ensemble of predicted monthly temperature and precipitation anomalies using four numeric weather prediction models. Beyond the first 4 months, forecasts are produced using Environment Canada's statistical model.

In addition, before the fire season, a 4-month seasonal forecast is produced on April 1 and on May 1, together covering the period from May 1 through August 31. After May, creation of a seasonal forecast is suspended.

Forecast maps are available for the following themes:

The Forecast Severity Rating map presents forecasted monthly or seasonal severity ratings. This map shows the predicted conditions unadjusted for climatology. For months based on the ensemble forecast, the map reflects the median station values of the 40-member ensemble.

The Average Severity Rating map presents 30-year average monthly or seasonal severity ratings. This map shows the regional climatology of severity conditions.

The Forecast Severity Anomaly map presents the ratio of the forecasted severity rating to the average monthly or seasonal severity rating. This map indicates which regions are predicted to be above or below the regional climatological average in a normalized form (where 1 = average conditions). Note: This map alone does not indicate which regions of Canada are predicted to have above-average fire seasons. Such conditions can be approximated by comparing this map with the Forecast Severity Rating map.

The Confidence Rating map presents the ratio of the standard deviation of the forecasted severity rating to the average monthly or seasonal severity rating. This map indicates the confidence in the forecast according to the variation of ensemble members around the predicted value.

Disclaimer: These forecasts are experimental and have yet to be fully validated and calibrated. These forecasts should be viewed not for their accuracy, but for the general trends they present and are to be used as a long-range planning tool by fire resource managers.

More information about the calculations for monthly and seasonal severity forecasts is available in the Background Information.

Date modified: