Climate Watch
By Rick Thoman Alaska Climate Specialist Alaska Center for Climate Assessment and Policy International Arctic Research Center/University of Alaska
Fairbanks
On any given day in western Alaska, it might be windy and mild or windy and cold, or not windy at all, be it warm or cold.
While the lowest winter temperatures are typically associated with light winds (this is likely less true in the Bering Strait), does this hold true at the longer timescales? If there is some relationship between temperature and wind, this might be helpful for planning. While wind outlooks are not something that has historically been included in monthly or seasonal forecasts, can we infer something about winds from temperature outlooks?
We would expect this would vary through the course of the year. In winter the highest temperatures are almost always associated with storms that bring milder air from the south into the region.
In the summer the highest temperatures are most definitely not associated with Bering Sea storms, but rather result from warm high pressure and usually occur with light winds.
To test out this idea let’s look at February and March temperatures and winds since 1999 from the Nome airport. Since we’re interested in possibly extending the use of climate outlooks we’ll use the monthly difference from average for both winds and temperatures. The results in the graphic are very encouraging. During the late winter and early spring there is a surprisingly strong correlation, with warmer months typically windy and cold months having lower average wind speeds. In fact, almost half of the variation in average wind speed for the month is accounted for by the temperature departure from average. This correlation is far higher than, say, the average temperature or total precipitation compared to El Niño or La Niña. Now there are exceptions: even in this 48-month sample there are some months that have bucked the relationship, but not many. And of course, this is specifically for Nome. This might look entirely different in the Bering Strait or even in places like Topkok that get the cold roaring north winds pouring out from the interior Seward Peninsula much more frequently than Nome.
But for Nome at least, we’ve got a new tool in our climate outlook toolkit.