A powerful southerly flow of air aloft is once again transporting extremely warm air for the time of year up to Alaska. The morning balloon soundings from Anchorage and Fairbanks show a deep layer of above-freezing air, extending up to nearly 8000 feet above sea level at Fairbanks and an extraordinary 9500 feet at Anchorage (see below). The 700 mb temperature of -0.1 °C at Anchorage is close to a record for the time of year.
The warmth won't last long in the interior this time, as the surge of warm air heads quickly east later today and the freezing level drops rapidly later today and tonight. It will be interesting to see if valley locations cool enough for accumulating snow tomorrow; if not, then October may end as the least snowy on record in Fairbanks (0.1 inches so far).