First things first - the March 15th - April 15th forecast for geopotential heights. Blue would suggest a cooler than usual atmosphere (from a lower 500mb level) and a red color would suggest a warmer than usual atmosphere (from a higher 500mb level). I ran a weighted average of my most similar years from my original November winter forecast (1952, 1967, 1970, 1978, 1979, 2009) up through April 30th. After April 30th, I have gone with a new list of years.
This forecast for geopotential height anomalies is a monthly index running from May 2013 through October 2013. My confidence at this time is low however I believe the large scale patterns (Pacific Decadal Oscillation, El Nino Southern Oscillation) will pan out very much similar to last summer. The new years chosen for my spring/summer index on similarity are 1952, 1967, 1979, and 2012.
My early concern is this blocking pattern showing up towards September (green over Greenland) - this is a similar pattern to what showed up last hurricane season.
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| 1952 hurricane season |
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| 1967 hurricane season |
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| 1979 hurricane season |
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| 2012 hurricane season |
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