Monday, July 18, 2011

The New Normals are Here


Eagerly awaited by climate fans everywhere, the 1981-2010 normals were released by the National Climatic Data Center earlier this month. Starting August 1, these will replace the 1971-2000 normals in the United States. Here is a quick look at the new normals for Fairbanks and how they have changed from the 1971-2000 set.

The warming in winter continues as the cold winters of the early and mid 1970s have dropped off, and this set comprises almost entirely the warm phase of the PDO. The other big temperature change is in June. Although not large in absolute terms, it is the largest standardized change of any month. This reflects the fact that temperatures don't vary nearly as much in summer as in winter. This early summer warming directly ties in with increased fire seasons.

For precipitation, the only really dramatic change is in July, with a big bump up, enough to make July solidly the wettest month of the year. Traditionally, August in Fairbanks has been the wettest month of the year, but in fact Fairbanks has been near the eastern edge of the area in which August is the wettest month of the year, and that line has clearly shifted westward.

3 comments:

  1. As the climate focal point in the Eureka office I am too am looking at the normals. I'm curious, what are the standardized differences in your table? From a quick first glance it doesn't look like ours changed much.
    Matthew

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  2. Matthew,

    I calculated the standardized change by dividing the change by the 1981-2010 standard deviation of the monthly value. So, the "standardized change" is really the change expressed as a standard deviation. So the June change was 0.35 standard deviations of the June 1981-2010 mean/stdev. Make sense?

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  3. Ok, I think I understand what you mean. That number will show you what changes were the most significant in relation to the standard deviation.
    Matthew

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