The Wintertime Arctic Front and Its Effect on Fairbanks, Alaska

Abstract

Surface and upper air data for November 1974?February 1975 were examined in order to determine a method to locate and predict the movement of the wintertime arctic front over Alaska. Ten cases each of the front passing north and south over Fairbanks were studied, Frontal effects an Fairbanks were noted and methods to forecast the timing of the frontal passage at Fairbanks were determined. Movement of the arctic front over interior Alaska was found to be directly related to the location and movement of large low-pressure systems in the Gulf of Alaska. Only very light snowfall accompanied the front as it passed northward over Fairbanks. However, southward passage of the front accounted for 77% of the Fairbanks snowfall during the four mouth period. A marked temperature and moisture difference was evident between the two air masses separated by the arctic front. Periods of extremely low temperatures with clear skies and ice fog were observed when the front remained south of Fairbanks for several days. Cloudy skies and above normal temperatures predominated when the front was to the north. The 850 mb analysis using 2°C isotherm separation and 30 m height difference and the plotted Fairbanks radiosonde are suggested as aids for use in forecasting the movement of the arctic front across Fairbanks.