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.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEizYnVYdZrpFuvbdsjvTYoDnGMUQEoV7w8uGjcAc-RTSgCRaXmzYHrtJeIr4y38r1K8vpNjuD4X1JiIdH1hWmnhkXSP9SghPDaMzvaN-OqBAqu0BQIq1L9WmML3Ba3pfsPyqWDprECCS60/s320/1952hurr.jpg) |
1952 hurricane season |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-2KQ6H68dG61l6532QwYTjsx6wuQZ6nmayv-KyV4cIAl6qHYLwKVVXaBZk60Pz01sUs0PS2IN9CX0CeEQL92sJF0ZeYm1IsnZN4MDDUIHL8PmDIJTm_8D_ZLkQcnZ3ZpOHQOtZkK_3wU/s320/1967hurr.jpg) |
1967 hurricane season |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggKkhukEe3xCI7vVrwsPQW4Gtgh3zoWWZEE875S-S0kJ9PtIGvOtDEd49jR7MQEj1XNjB0scAUr5pk8VGVgkevFyEC2TFB8-W9O26QMtw_BfW7fEb1_fZ90hAlNlxZZwhUcjZL7-Dbwts/s320/1979hurr.jpg) |
1979 hurricane season |
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqZ6m5NUeoJDebmBMgG5rzaHsAwfuC1jVjObcomK2Q2P8iZL3N5FUDsXy1SvkPA7WwvnqJUfq34qUOiWDTiHekW4zgLy9HJfsTsUsesf3wA1y14rjWy4JUmfelYY2RgNpV_JaJMwKEWLk/s320/2012hurr.jpg) |
2012 hurricane season |