Alaska parking lakes circa 2020s/Craig Medred photo

This is global warming

After the winter of much snow has come the summer of much rain to dampen the spirits of the more than half of all Alaskans who live in the 49th state’s urban core.

Welcome to the world of climate change.

Decades ago, this is what the first global warming models were predicting: the northward march of traditional climate zones. Juneau, the state’s capital, would become more like Seattle. And Anchorage, the state’s megapolis, would become more like a notoriously rainy Juneau.

“Average monthly precipitation is projected to increase during all months in Anchorage, with some variability from decade to decade” is the forecast from the Center for Climate and Energy Solutions.

And the Anchorage Metropolitan Area appears to be tracking the prediction. The only real difference between Anchorage weather this year and last year was that the rainy season started earlier.

Last year “at Anchorage, there were 48 days in August and September with measurable rain (0.01 inches/0.2mm or more), by far the most in any two-month period,” the Alaska and Arctic Climate Newsletter from the Alaska Center for Climate Assessment and Policy reported in a yearly review. 

Be ready for more.

The U.S. Department of Agriculture’s climate forecast for the Chugach National Forest, which borders the Municipality of Anchorage to the east, and covers the Kenai Peninsula just to the south predicts that “change associated with warming temperatures and increased precipitation will result in dramatic reductions in snow cover at low elevations, continued retreat of glaciers, substantial changes in the hydrologic regime for an estimated 8.5 percent of watersheds, and potentially an increase in the abundance of pink salmon.”

Snow, no snow

OK, so the snow prediction was way off for 2022, but then snowfall is very hard to predict because a shift of just a couple of degrees in temperature can turn significant rain into mountains of snow, and such small temperature changes are the norm within normal weather variation.

Thus a few degrees of temperature change can spell the difference between “dramatic reductions in snow cover at low elevations” – as Anchorage witnessed in 2016, 2017 and 2018  – or dramatic increases in snow cover at low elevations as Anchorage witnessed last winter.

About the only ray of hope for sun lovers here is that some models predict that although there will be more rain, warmer weather will, in general, speed evaporation and lead to overall drier conditions.

So maybe you can figure on more rainy days but fewer muddy ones after the rain stops falling.

Predictable

These forecast shifts in climate seem logical enough. Marine and continental variations in climate on the planet are well established as are the south-to-north shifts from tropical to temperate to subarctic to arctic temperature zones.

It makes sense that these zones would steadily migrate from south to north as the planet warms though the comparisons of Juneau to Seattle and Anchorage to Juneau are likley way ahead of their time in reality. Even a fast-changing climate is unlikely to move that fast.

Juneau becoming Ketchikan; Cordova becoming Juneau; and Anchorage becoming Cordova seems more reasonable. And this, it is worth noting, is part of a process that has been underway for a long, long time.

Along with glacial retreat, which turned the ice-covered Glacier Bay of the 1750s and before into a 65-mile deep tourist attraction into which cruise ships can sail to let tourists view glaciers and marine mammals, the northward march of warmer climates has a lengthy history that can be tracked with changes in vegetation.

“Sitka spruce, mountain hemlock and western hemlock did not appear in southcentral
Alaska until about 3,000 to 4,000 years before present,” U.S. Forest Service scientists observed  25 years ago. “Stands of coastal conifers were the result of a migration northwestward along the coast of the Gulf of Alaska that took place as storm tracts strengthened during the late Holocene.”

Those storm tracts have only continued to strengthen in recent years, and the march of the coastal rainforest easily tracked by that mix of Sitka spruce and western hemlock has continued its northward and then westward creep around the rim of the Gulf.

Sitka spruce, according to researchers, didn’t reach Kodiak Island archipelago until about the 1600s, but has been marching relentlessly across the island to the west ever since. Meanwhile, the defining species of the temperate rain forest has spread “north and west as far as Mount Susitna on the northwest tip of Cook Inlet, along the east coast of the Alaska Peninsula, and nearly to the southern boundary of Katmai National Park,” according to the University of Alaska’s Cooperative Extension Service. 

The storm tracks that pushed the trees northward have become so common in modern-day Alaska that most who’ve lived here long are now familiar with the term “pineapple express” used to identify the pulses of warm, tropical air that surge north across the Pacific from near tropical Hawaii to slam into the underbelly of the 49th state.

They can bring plenty of rain to the Anchorage area at almost any time, and there has been plenty this summer.

At this time, the National Weather Service is reporting 16.48 inches of precipitation has fallen on Anchorage since the start of the year. That is not a record, but it is a significant 4.5 inches above normal.

The record is 20.9 inches in 1989, and it is easily in reach this year given that the average annual rainfall for Anchorage in the months of October, November and December totals 4.17 inches.

If those three months combined produce even a quarter inch more precipitation than normal this year, 2023 ties 1989, and if they’re more than a quarter inch over the norm, Anchorage sets a new record.

Could be worse

With all the Anchorage whining about the wet that has been going on, however, it is worth putting this year’s moisture in perspective.

Anchorage is nowhere near another Juneau or, for that matter, a Yakutat, Cordova, Valdez, Seward or even Homer. Anchorage weather, even at its wettest, is drier than in these other port communities hard up along the Gulf of Alaska.

Be thankful the city at the head of Cook Inlet is tucked well into the Alaska underbelly. The 220 miles between Anchorage and the North Pacific have a large influence on precipitation.

Juneau is about 155 miles closer to the Pacific, and that changes everything. Average rainfall at the airport there is 54 inches per year, and this is the local dry spot. The city gets more than 90 inches downtown, according to the National Weather Service.

Thus, in the best-case scenario, this makes an average Juneau almost three times wetter than Anchorage at its worst. And in a worst-case scenario, that average Juneau is more than three times wetter than Anchorage at its worst.

In fact, no matter how much Los Anchoragites might whine about this summer’s rain, they should appreciate how much drier the city is than any of those closer to the coast.

Homer gets an average of 47.7 inches of precipitation per year, more than twice Anchorage at its wettest, with Seward at 68 inches, Valdez at 95.6 inches,  Cordova at 148.37 inches and then there is Ketchikan at a staggering 152.38 inches per year or an average of more than four-tenths of an inch per day depending on how you want to look at it.

Anchorage looks almost like a desert compared to these communities, and even if it sets a new record this year it will still be far short of the standards of soggy Seattle, which despite being drier than any of the Alaska port cities listed above still sees an average 37.18 inches per year. 

That’s more than twice the Anchorage average, but still way less rain than falls on Juneau.

Juneau can only dream that it gets more like Seattle when it is likely to only get more like Ketchikan, which might be enough to make even many Juneau residents want to move the state capital to some drier part of Alaska.