A Comparison of Fire-Weather Severity in Northern Alberta During the 1980 and 1981 Fire Seasons

Abstract

The burning potential of two major fire seasons in northern Alberta is evaluated with the use of the Canadian Forest Fire Danger Rating System (CFFDRS). Fire danger class frequency and severity ratings based on the Fire Weather Index (FWI) component in the CFFDRS were utilized in the evaluation. Daily fire-danger reports from 16 selected fire weather stations distributed throughout the northern half of the province provided the basis for the analysis. Although the Seasonal Severity Rating (SSR) for 1981 was slightly higher (SSR = 3.1) than that of 1980 (SSR = 2.5), the area burned in 1981 was about double that of the previous year. The period of critical fire weather began early in the 1980 fire season and prior to the normal summer lightning pattern, whereas in 1981 it occurred during the latter half of the fire season and coincided with the majority of the lightning incidence. FWI severity ratings were not designed to portray a complete picture of the total potential fire containment job but rather to provide an objective basis on which to compare the severity of one season's fire weather with another. Key words: Fire Weather index, fire season seventy rating, critical fire weather, lightning occurrence, northern Alberta.