Climate Watch

NOAA’s Climate Prediction Center outlook for December for Nome and most of western Alaska calls for very slightly increased chances of significantly below normal temperatures for the month. The outlook for total precipitation (melted snow plus any rain) does not favor above or below normal. For reference, the normal December temperature at Nome is 9°F, normal snowfall is 15 inches and the normal precipitation is just over one inch. Of course, this is also the darkest month of the year, with the least amount of possible sunshine this year on December 21.

As we look toward the future, one tool that people often ask about is whether extremes of one month carry forward to the next. In this case, we are coming off one of the coldest Novembers on record. Does that mean we’re more likely to have a really bitter cold December? If we look at all the Novembers in Nome climate history, since 1907, and focus on just those months that were more than 10°F colder than the (current) normal of 18.2°F, what we see is that in about half those years December actually was milder than November, and two years (1931 and 1962) had a December that was a lot milder. Two years, 1955 and 1974, a very cold November was followed by a significantly colder December. The remainder of the very cold Novembers were followed by a December that typically had similar temperatures to what happened the previous month. Of course, the normal temperature in December is more than 9°F lower than November. What all this data juggling shows is —that if the past is a guide — the NOAA forecast for slightly, but not dramatically increased chances of below normal temperatures is in line with what has happened in the past right here in Nome. This kind of detailed, place-specific information is not part of the Climate Prediction Center’s toolbox, as the CPC is responsible for monthly and seasonal forecasts for the entire county. This convergence of evidence is one of the things we look for when creating climate outlooks.