Tuesday, April 16, 2013

Cold April in Context

The average temperature the first half of April in Fairbanks was10.8ºF. This is a remarkable 16.3 degrees below normal and the fourth coldest of record (second coldest in the WB/NWS era). The chart plots the mean temperature the first half of April and the 10-year running mean.

The years with coldest first half of April and the mean temperatures are:

1911:  4.4ºF

1985:  9.8ºF
1924:  9.9ºF
2013: 10.8ºF
1986: 11.0ºF

The 10 year running mean shows nicely that there has been little trend in April temperatures over the past 50 years except for the decade or so of warm Aprils in the 1990s. This year is a good example of an "outlier" that we have no reason to think is tied to a larger pattern (unlike say, Barrow temperatures in October).

Here's a link to the NWS Alaska Region Facebook graphic showing how the cold weather this month is distributed across Alaska. Northwest and Southeast Alaska have not been notably cold but in between it sure has been.

3 comments:

  1. Nice chart, showing the outliers about once every 30 years!

    It's interesting that there have only been 2 days with max temperature above freezing in April thus far in Fairbanks, which ties the record from 1961. For the year to date, I count 11 days above freezing; the record smallest number is 8 in 1972.

    Richard

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    Replies
    1. Fairbanks has not been above freezing April 3-18. That is unprecedented. I'll have more analysis this weekend.

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  2. The CPC is calling for much below normal temps for 4/21-23:

    http://www.cpc.ncep.noaa.gov/products/predictions/threats/hazards_d3_7_contours.png

    Then an EC temp forecast for May:

    http://www.cpc.ncep.noaa.gov/products/predictions/long_range/fxus07.html

    A Statisitical tools vs Dynamic Model conflict? Might as well flip a penny and save the rest of the $ for something else.

    Gary

    ReplyDelete