Climate Watch
With all the rain this summer, many folks have asked about whether this is a sign of things to come for western Alaska. Happily, recent advances in climate science allow us to answer that question in some detail.
For most of the Seward Peninsula, eastern Norton Sound and St. Lawrence Island, the trend over the past 50 years (1971-2020) is indeed for more summer rain. However, the graphic shows that for western
Alaska this is a regional trend.
North of Kotzebue as well as much of the northwest Bering Sea the trend has been for less summer rain.
For the Yukon-Kuskokwim Delta and through the Bering Strait and northwest Seward Peninsula, there has not been much of any trend.
This kind of pattern suggests that what we see reflects variations in the summer storm track over the past half century rather than a strong climate change “fingerprint.”
Since the favored summer storm track is part of the natural variability of the atmosphere, there’s no reason to think that the unusually stable pattern we’ve seen this summer will be favored in the future.
The climate change “fingerprint” becomes more noticeable when we examine longer periods of time over larger areas. For example, yearly precipitation —rain plus melted snow— has increased across most of Alaska, and indeed over nearly the entire Arctic.
With decreasing sea ice coverage and warming oceans providing more water to the atmosphere through increased evaporation, this is exactly what we expect.