Aspects of Winter Temperatures in Interior Alaska

Abstract

The interior basin between the climatic divides of the Brooks and Alaska Ranges has extremely low winter temperatures in contrast to the milder regime of both southcentral Alaska and the region on the Arctic Slope of the Brooks Range. There is a cold pole centered on the Yukon flats and extending over the Yukon and Tanana valleys. Two local factors in the occurrence of low winter temperatures are the wide expanse of relatively flat and low-lying surface suited to the development of substantial low level temperature inversions in winter when the radiation balance of the surface is strongly negative; and encirclement by a mountain mass which is effective in preventing the weaker low level synoptic scale weather systems from invading the basin. Large-scale circulation factors associated with extreme years are described.