An Alaska Statewide Daily Temperature Anomaly Index

Alaska’s vast expanse, complex terrain and variety of climates make statewide generalizations about climate variables a difficult task. The National Centers for Environmental Information began producing monthly climate division and statewide temperature and precipitation means and anomalies in March 2015. This was a major step forward for routine climate monitoring and analysis in Alaska, but partners, the media and public are often interested in anomalies at shorter timescales. To help address the common question of the type “has it been cold in Alaska lately?” we developed a daily temperature anomaly index based on 25 National Weather Service ASOS around the state selected to provide reasonable representation of Alaska’s diverse climates. The index represents a transformed Z-score of the mean of the standardized individual station anomalies. In this presentation we will discuss the methodology and science of the index, some of the pitfalls and future plans.