The Anchorage Hillside temperature at 7 p.m. on Halloween was 47 degrees, two degrees down from a daily high that fell just a degree short of the record for the date. Halloween’s “normal high,” as the National Weather Service categorizes weather as if anything was normal in Alaska, in the state’s largest city is 33.
Snow that had fallen earlier in the month was long gone, though some was still hanging on down in the Anchorage Bowl which is something of a big sink for colder air sliding down the Chugach Mountains.
Welcome to the new north. This is the start of the third year in a row coastal Alaska has eased into a winter more Pacific Northwest than Arctic.
Climatoligists says there is no reason believe this is the new norm, but they admit that it could be the new norm. For global warming true believers, it’s downright scary.
Old timers recall how trick-or-treaters in Anchorage always had to wade through snow on Halloween’s past, but memory is a badly fallible thing. Historically only 55 percent of Anchorage Halloweens have been dressed in white, said climatologist Brian Brettschneider.
He had no idea of how many of the other 45 percent were snow free but bitterly cold, but there were a few. In 2008, the Halloween temperature at Anchorage’s Campbell Creek Science Center dropped to zero.
Suffice to say, historically Anchorage either had snow to insulate the ground by Halloween or a lot of frost digging its way ever downward. Normally, again an NWS term, the average, overall, daily temperature hits freezing on Oct. 21 and just keeps going down from there.
By Halloween, the 24-hour average is at 27 degrees. This year, it’s likely to come in somewhere between 38 and 40 on the day. It was 38 on the day before Halloween.
But Brettschneider makes a good point about memory. We tend to remember the worst or most difficult a lot longer and a lot better than the best or easiest. Who remembers those Halloweens of the early 2000s when the week started with temperatures in the high 40s?
“It’s easier to remember snow or a cold snap,” Brettschneider said.
But wasn’t this supposed to be the year La Nina, the chilly ocean current the opposite of El Nino, that was going to bring a real winter back to Seward’s Icebox? Yes, and it still might.
The national Climate Prediction Center is still posting a La Nina watch. They are still giving it a 70 percent chance of developing this fall and a 55 percent chance of persisting through the winter.
So maybe those who love snowmachining, skiing, snowboarding, on-snow-fatbiking and the like will get the winter they want sometime starting in January. Up until then, well, as Brettschneider notes, “we’re starting with such a warm baseline.”
The Gulf of Alaska south and east of Anchorage remains a big pool of warm water. Colder waters are creeping into coastal bays and inlets, but in general the waters of the coast remain unusually warm.
With the Gulf “at or near record warm, it’s going to be really hard for Alaska to cool off,” Brettschneider said. “Where will the cold air come from?”
Siberia to the west, maybe? Cold air from the arctic could slide into Alaska from the northwest and settle over the Gulf long enough start to pull some of the heat out of the water. Or that La Nina could strengthen and bring cold water from the deep ocean of the tropics swirling north into the Gulf mix, but either of those changes are expected to take time.
Brettschneider isn’t real optimistic about a good winter for skiers, and he suggests fat-tired cyclists might want to stud their tires.
Part of the reason for the latter is because this fall started off “different a lot from last year,” he said. “It’s very dry.”
The winter of 2015-16 started off warm and wet. The winter of 2016-17 is starting off warm and dry. In the warm and wet conditions, skiers could find snow if they went high enough or close enough to glaciers that formed microclimate pockets of cooler air.
Drier means a lot less snow even there.
All around the Gulf coast, conditions now are “way below normal to record dry,” Brettschneider said. “We’re in an uncommonly dry pattern.”
Will that continue? Will the warm linger?
“It would be very uncommon to have three winters in a row” widely off the norm, Brettschneider said. “But you can’t know it’s not a new norm.”
Check back in another decade or so, and we should all have a better idea of what these strange winters meant. Right now, about all you can do is embrace the best. Warm and dry is a lot better for cycling or hiking than warm and wet which is good for little.