Climate Watch

By Rick Thoman Alaska Climate Specialist Alaska Center for Climate Assessment and Policy International Arctic Research Center/University of Alaska Fairbanks

Forecast zones have been the staple of National Weather Service public forecasting in Alaska since the 1970s. Even before that, local forecasts were produced for some communities like Nome, where NWS —and the Weather Bureau before— had offices.

Although there have been some tweaks over the years, this month the NWS has made the most significant changes to public zones in 20 years. For parts of western Alaska there is little modification. The area covered by the Southern Seward Peninsula

Coast doesn’t change at all and for the Eastern Norton Sound and Nulato Hills zone there are no changes for communities.

The big change is in the Bering Strait and St. Lawrence Island area. St. Lawrence Island will now be its own zone, instead of being lumped in with the Bering Strait. This will allow for much improved forecasts.

Another important change is that the northern Seward Peninsula coast has been split off from the Chukchi Sea coast northwest of Kotzebue. This will result in more representative forecasts for Shishmaref.

On the other hand, the Bering Strait is now split into two zones: Wales is the same zone as Brevig Mission and Teller, while Little Diomede is the same zone as Shishmaref.

It’s important to know that if you use weather apps on your phone to get weather forecasts that this will not change what you see. Forecasts on apps are extracted from digital databases.

For most people the most obvious impact of this change will be what’s read out on radio and for Watch, Warnings and Advisories. The smaller zones will mean that warnings will be more focused. For example, storms and weather fronts in winter sometimes weaken as they move into the northern Bering Sea and bring blizzard conditions to St Lawrence Island but not beyond. With the new zones, the Bering Strait will not be broad-brushed in with St. Lawrence Island.