An Arctic cold front from Siberia is headed toward Anchorage and by Tuesday could drop the season's first snowfall on the city, according to the National Weather Service.
The "unseasonably strong" weather system could bring "the threat for accumulating snow" to parts of Southcentral Alaska, including Anchorage and the Matanuska and Susitna valleys, the NWS Anchorage forecast office wrote in a special weather statement Sunday.
Late September snow is far from unheard of, said NWS meteorologist Jason Ahsenmacher, but the system moving in is colder than what's typically seen.
"It is a pretty cold system for this time of year," he said. "It's unusual."
On Tuesday, temperatures are expected to drop throughout the day. Rain should turn into snow by afternoon, he said.
Meteorologists say there's a high likelihood snow will fall Tuesday but much less certainty about how much might accumulate or whether it will stick.
(FYI: Studded tires have been street legal in Anchorage since Sept. 15, according to the Alaska Department of Transportation.)
Skies are expected to clear Wednesday, and the week's coldest temperatures -- expected to be in the 20s -- will likely arrive Thursday.
By the end of the week, conditions should warm slightly with overcast skies and precipitation.
If snow does accumulate Tuesday, it won't be the earliest the city has seen.
The earliest accumulating snowfall of more than a trace fell on Sept. 21, 2006, according to the NWS.
The one-day snowfall record for September in Anchorage is 6 inches, which fell Sept. 25, 2004.