Update, 5:30 a.m. Wednesday: A winter storm is tracking farther east than originally expected, diminishing the potential for heavy snowfall in Anchorage and the Valley, according to a Wednesday morning update from the National Weather Service.
"A wintry mix of snow, rain and pockets of light freezing rain are all likely during the morning commute until the cold air works its way in," the weather service said.
Forecasters expect heavier snowfall in the Matanuska-Susitna Borough — 3 inches or more along the Glenn Highway from Palmer to Chickaloon.
Find the latest forecast for your area at weather.gov/afc.
A big plume of moist air is heading to Southcentral Alaska that will bring snow and rain, though the deluge may largely miss Anchorage, according to the National Weather Service.
The forecast calls for snow in the Anchorage area to start falling after midnight Wednesday, with possible accumulation of 1 to 3 inches.
In a special weather statement early Tuesday, forecasters said there could be moderate to heavy snow from the western Kenai Peninsula to Anchorage and up into the Matanuska-Susitna Borough.
"This would produce hazardous travel conditions along area roadways," the National Weather Service said. "At this point in time forecast confidence in both timing of snowfall and amount of snow accumulation is low."
Meteorologist Kyle Van Peursem said the moisture from the tropics, sometimes called the Pineapple Express, will hit the central Chugach Mountains.
"The really tricky question is how far west is this plume going to get," Van Peursem. The more recent models put Anchorage on the periphery of it, he said.
Eureka and the Copper River Basin can expect heavy snow. Thompson Pass may get 3 to 4 feet, on top of 20 inches that just fell, he said.
Coastal communities around Prince William Sound can expect rain — and the mountains, snow, he said.
The snow and rain will taper Wednesday night and another system could hit Thursday, he said.
Around Yakutat, on the northeast Gulf of Alaska coast, 2 to 3 inches of rain could fall Tuesday night.
Meanwhile, the weather service warned that avalanche danger is high in the backcountry around Hatcher Pass. Recent heavy snow and high winds have created large areas of unstable snow, according to the Hatcher Pass Avalanche Center. The weather service transmits avalanche warnings for the Hatcher Pass center.
Avalanches can run long distances into flat areas. The warning was in effect through Tuesday at 10 p.m.