Winter rain has caused icy conditions across much of Southcentral Alaska. It led to school closures and delays Tuesday from the Kenai Peninsula through Anchorage and up to the Mat-Su Borough. On Monday, Anchorage hit a record high temperature of 42 degrees, a degree warmer than the previous record for this date set in 2014.
National Weather Service climate researcher Brian Brettschneider said this winter, the state has seen a dominant weather pattern of southerly flows bringing warm weather from across the Pacific Ocean.
“As the air flows over that really, really warm water, it warms up more than it used to,” Brettschneider said. “So that's one part, and then it also holds more moisture, because warmer air has the capacity to hold more moisture.”
He said it’s not uncommon for a weather pattern to take hold for a large chunk of the winter, but this winter has seen a few colder spells.
“Fairbanks almost hit 40-below about a week ago,” Brettschneider said. “So we can still get cold, but having a dominant flow pattern that lasts for much of the winter is pretty common.”
Brettschneider said it’s hard to pin the southerly flow of warm weather to changes due to a warming climate. However, he noted that diminished sea ice in the Arctic is adding heat to the atmosphere and that can make it easier for storms to form.
Despite the fourth snowiest October on record, roughly half of the precipitation in Anchorage has been rain this winter. Brettschneider said that pattern is becoming more common.
“It's happened before,” Brettschneider said. “But it's happened now, three or four times since about the year 2000. So there definitely seems to be an increase in the propensity for that to happen.”
Alaska is currently in a La Niña weather pattern, which typically means cooler northerly systems coming through the state. Brettschneider said it’s still possible the La Niña will bring some cool weather to the state, but for now, the forecast looks warm.
“We look to be kind of in a warm pattern statewide for about the next 7 or 8 days, and then we hopefully should get back to more typical Alaska winter conditions,” Brettschneider said.
Brettschneider said this winter is about 10 inches shy of the average snowfall, but he thinks the city’s snow pack will survive the rainy weather.
