Climate Watch

Easily the most frequent climate question I’m asked that I don’t have an immediate answer for is something like: “Is it getting windier?” or “Is it stormier than it used to be?”

Some of this stems from uncertainty about what constitutes a storm, and people may have different definitions. Another difficulty is how wind data is observed and reported, which has varied dramatically over decades, compounded by the sensitivity of wind speed to the presence of obstacles like buildings and how far above the ground the wind is measured.

I’m always looking for new ways to look at this question, and just last month a group at the Finnish Meteorological Institute released a new set of data that allows us to get a new perspective on this question. The new data uses a high-resolution climate analysis model to calculate the number of windy days each year from 1950 through 2021. One of the new features of this dataset is that the Finnish group has cleverly defined a “windy” day so that it’s in relation to what is windy for any given place and a particular time of year.

For Nome this varies from about 13 mph in the late spring and early summer to almost 20 mph in late February. When we look at the changes in the number of windy days over the past 72 years, for western Alaska it’s regionally quite mixed trends. For the southern Norton Sound coast south to the Yukon-Kuskokwim delta there has been a decrease in the number of windy days (this is especially notable in the lower Kuskokwim region). On the eastern Norton Sound coast and St. Lawrence Island this data shows no significant long-term change in the number of windy days, but on most of the Seward Peninsula and Bering Strait coast the number of windy days has increased.

In the graphic I plot the number of windy days each year for the greater Nome area (roughly Cape Woolley to Safety Sound and inland about 20 miles) along with the trend line. The number of windy days has varied from 11 days in 1953 to 62 days in 2019. The trend line shows about a six-day increase. That may not sound like a lot, but it represents a 19 percent increase in the number of windy days. The other feature that captures my eye is that since 2010 there haven’t been any years with a low number of windy days. One downside of this data is that it’s currently only available at the annual timescale. We’d really like to have this information available at the monthly or at least seasonal scale. But for now, we do have this as a first guide, that at least for parts of the region, including Nome, windy days are more frequent nowadays than in the later 20th century.