Chances are, fall and winter will bring warmer and wetter days
Rick Thoman came to Nome from Fairbanks Oct. 23 with about half a dozen programs giving different groups an idea of what to expect in weather this fall and winter.
Thoman, 30 years a weatherman who started his career in Nome, began with a recap of last spring and summer for the group attending the Strait Science session Oct. 24 at Northwest Campus UAF.
There are good chances ice will form late and leave early, exposing dark water to absorb heat from the sun, meaning even more ice melt and resistance to expanding the extent and thickness.
Will there be snow like last year when City crews and private contractors struggled to keep Nome’s streets passable? When snowdrifts blocked windows and doors of residences?
“If you haven’t put the blade on the pickup, get it on there,” Thoman said.
Later in the program, following discussion of sea surface temperatures, loss of sea ice, wind direction, heat absorption on light and dark surfaces— all the things which impact climate and weather —Thoman addressed the folks without powerful pickup trucks and snow blades
“If you have a snow shovel, don’t sell it on eBay,” he quipped..
Thoman gave a run-down of where we’ve been, climate and weather-wise: Very warm ocean. Persistently warm land. Record low sea ice.
Thoman has been looking at the relationship that exists between sea surface temperatures and sea ice. “Can we use what we know as our extremely warm oceans to get a handle on what the upcoming sea ice season might be?” Thoman said.
For the five months from May through September there has been no sea ice, with surface temperatures above normal for all of the Bering Sea except for the far southwest, most of the Chukchi Sea, almost all of the Alaska portion of the Beaufort Sea, Gulf of Alaska and Norton Sound.
How much above normal?
Kotzebue Sound average has been averaging 8°F above normal, out in the open Chukchi Sea, 7 to 8° F above normal, the same off Utqiagvik, for the five-month warm season, according to Thoman. In Norton Sound you see 5°F to 7°F above normal
“Really quite amazing for a five month period,” he said, “Open ocean temperatures hardly ever vary more than a few degrees,” Thoman said. The ‘normal’ temperature is derived from temperatures over a 30-year period, from 1971 to 2000. “Six of the last 10 summers have been in the warmest in the past 120 years. Only one top 10 year was in the 20th Century. The rest are all since 2000,” Thoman said, pointing to his charts, with a lot of red on them showing comparatively red hot sea surface temperatures.
“Every year now is in the top 10 years—very amazing.
“You have lived through an epic weather setting event,” Thoman told rapt listeners. “When you look at the sea ice, the ecology and the food web, it’s not just what is going on at the surface. Waters in the upper 300 feet of the water column are showing fire engine red on much of the Southeast Bering Sea. In the Northern Bering Sea, near the Alaska coast, except for a small area of cool, and south of the Aleutians the warm surface penetrates to depth.”
The impact of the warm surface temperatures going down through the water column has a big impact at the bottom of the Bering Sea. Thoman notes that Lyle Britt, fisheries research biologist, will come to Nome in about a week to reveal what his team has found in a bottom trawl survey of the Northern Bering Sea, what the fish are up to, whether the cold briny pool that is at or below 32° F, which collapsed last year, has returned.
The cold pool is a thermal barrier governing the distribution of species in the Northern Bering Sea and the Southern Bering Sea.
So, what is in store for the Nome area? There could be first sea ice, more than 15 percent, in the second half of December; for most of Norton Sound, the first half of December; down through the Bering Sea, the second half of December.
In January, ice may extend south down as far as St. Matthew Island.
“In February, practically no place gets their first ice in February,” Thoman said. “That tells me something, that we’re getting stormy south wind dominating. But in March, some places are getting ice, which tells me cold north winds dominating.”
All of Alaska has a chance for significantly more precipitation than normal, according to Thoman.
According to National Oceanic and Atmospheric Administration’s Climate Prediction Center, for November, “Western Alaska has 37 percent chance of more precipitation than normal, but 33 percent chance of being normal, and 22 percent chance of having less than normal—not much of a tilt,” Thoman said. “Temperature wise, western Alaska has a 65 percent chance of being warmer than normal, 30 percent chance of normal, and 5 percent chance of being below normal.”
According to the Climate Prediction Center outlook for the period November through January, western Alaska has a 55 percent chance of being warmer than normal and a 33 percent chance of being normal and a 55 percent chance of being wetter than normal and a 33 percent chance precipitation being normal. Mid-winter may essentially have the same odds for above normal and normal levels of temperatures and precipitation.
Close to home in western Alaska, the extent of sea ice and climate have impacts on daily life.
People living in coastal villages depend on ice for hunting and well-being of animal resources to put food on the table, Thoman emphasized. Environmental change is challenging travel and access to hunting, fishing trapping and gathering subsistence resources.
When and if ice forms and the extent moves south, the new ice will be juvenile ice only a few inches thick–easily scrambled into shards by winds, waves and storms. There is hardly any old multi-year ice remaining.
“It won’t take the 15 storms in a few weeks as last year in February and March,” Thoman said. “It doesn’t require that kind of unusualness. If we get 10 days of stormy weather, it will chew up large chunks of this ice because this ice is going to be only inches thick.”
In towns and villages the melting of permafrost is putting residences to rocking and rolling.
Folks are reporting that houses getting out level are causing them to walk uphill or down hill to other parts of the houses. Prospects of earning a living leveling structures look good. A cold snap will not repair the permafrost. Can it recover?
“Sure,” said Thoman but not in the time scales we care about. Permafrost takes a long time to melt. It takes a long time to build.
“But unlike sea ice, which could, but it’s not likely to, could regrow in a few years. If we can get ice to stop melting in a few years, we’d have multi-year ice,” Thoman said. “Permafrost doesn’t work that way, no matter what the air temperature does. Even if it get colder and stays colder, it will take a human lifetime to work into the permafrost.
What can change, Thoman said, is the depth at which there is permafrost.The depth of that layer that can respond. However, the deep, stable permafrost, if that goes, that’s beyond human timescales to change.
“When it is gone, it will take centuries to rebuild,” Thoman said.
Strait Science is a program sponsored by Northwest Campus UAF and Alaska Sea Grant.
Rick Thoman retired from National Weather Service after 30 years and went to work at Alaska Center for Climate Assessment and Policy at University of Alaska, Fairbanks. When he was 10 years old or younger, he knew he wanted to be a weatherman, he told the Nome Nugget.