Major storm expected to bring snow, wind, rain and possible flooding to Southcentral Alaska

A major winter storm is forecast to bring snow, strong winds and rain to a large swath of Southcentral Alaska from Tuesday night into Thursday.

Light snow was expected to begin in the western Kenai Peninsula and move through Anchorage and the Mat-Su into Wednesday afternoon, according to National Weather Service meteorologist Michael Kutz.

One to 3 inches of snow is expected to fall in Anchorage, with up to 6 inches at higher elevations, Kutz said Tuesday. North winds with gusts up to 25 mph are expected to cause blowing snow and low visibility, according to a winter storm watch in effect through Thursday afternoon.

Visibility was expected to be especially poor along the Knik Arm and Glenn Highway corridor toward Anchorage, the winter storm watch said.

Snow was expected to continue falling in Anchorage until Wednesday afternoon but could then change to rain as temperatures rise, Kutz said. The weather service issued a flood watch for the Anchorage area because up to an inch of rain is possible Wednesday evening.

“Rain on top of snow will lead to ponding of water on area of roadways,” the watch said. “Excessive runoff may result in flooding of low-lying and flood-prone locations.”

The precipitation is forecast to taper off Thursday afternoon, Kutz said.

“Things will get kind of slushy during the overnight hours and may even do a little light refreezing after dark, but it’s just going to be kind of a mess here through Thursday,” he said.

As forecasters analyze the coming storm, they see two potential scenarios that could unfold Wednesday and Thursday, forecaster Michael Ottenweller said during a livestreamed Tuesday afternoon update by the National Weather Service. One scenario involves lower temperatures and the likelihood that all precipitation would be snow, Ottenweller said, while the other would bring warmer conditions and a higher likelihood of mixed precipitation, such as freezing rain on top of snow.

Regardless of which scenario plays out, Ottenweller said heavy precipitation through Prince William Sound and the Anchorage Bowl is likely, as are blizzard conditions for Thompson Pass near Valdez and high winds along the Gulf of Alaska coast.

“Heavy precipitation is almost a guarantee,” Ottenweller said. “This system is bringing up a lot of moisture from the North Pacific.”

What’s more dependent on which track the storm takes is the type of precipitation in store for Anchorage and other areas, wind speeds, snow amounts and whether flooding will be as much of an issue.

“If the colder air pans out, snow amounts could be quite a bit more,” Ottenweller said.

Anchorage, for example, could see up to a foot of snow if conditions stay on the colder side, he said.

An Anchorage School District official said Tuesday that a decision about whether schools would be closed Wednesday or switch to remote learning would be made by 5:30 a.m. that morning, depending on road and weather conditions.

The Mat-Su was also expected to see snow Tuesday night into Wednesday, Kutz said. Northeast wind gusts up to 40 mph could cause blowing snow and low visibility, according to a winter storm watch issued for the area.

The western Kenai Peninsula is expected to see snow overnight Tuesday into Wednesday, paired with gusty northerly winds, according to a winter weather advisory. Snow is expected to start near Anchor Point and spread north to Nikiski, the weather service said. Roughly 3 inches of snow is possible for much of the area, with potential for up to 6 inches near Moose Pass and Turnagain Pass, Kutz said.

Flurries were possible throughout much of Southcentral Alaska on Friday, he said.

The storm is forecast to move into the area just days after Anchorage was hit with its first major snowfall of the season. The National Weather Service recorded a little over 6 inches of snow in the city by Sunday afternoon, which broke the previous Nov. 5 record of 3.8 inches set in 1964.

Roads were slick with fresh snow early this week. On Monday, Anchorage police received reports of about 29 collisions, seven of which had injuries, and 52 vehicles that had gone into the ditch or were disabled, spokeswoman Sunny Guerin said. By 12:45 p.m. Tuesday, nine collisions had been reported, including one with injuries, and 14 vehicles were in the ditch or disabled, she said.

Roads were expected to be slushy and slick through the region as the storm moves in, Kutz said.