Brett Anderson

Share |

New Update on the Long Range Through April

March 26, 2013; 8:30 AM ET

This is my latest interpretation of the European model (ECMWF) weekly long-range forecast output for North America.


Blocking pattern...when will it end?

The persistent blocking pattern across the far north (-Arctic Oscillation/-North Atlantic Oscillation) is predicted to weaken as we go into the first half of April, but it will be a slow process.

The CPC ensemble forecast (red line) for the Arctic Oscillation (AO) below continues to show a trend toward neutral by the middle of the month, though there is still some uncertainty.

You can also look back and see how low (in the negative) the AO (black line) was from late February through March. The AO was about as low as it ever gets back on March 19 and 20.

For a nice, brief explanation of the different phases of the AO and the NAO you can look at this presentation from the state climate office of North Carolina.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or


Comments left here should adhere to the Community Guidelines. Profanity, personal attacks, and spam will not be tolerated.

More Canadian Weather Blog

  • Snowstorm Update

    November 22, 2015; 11:15 PM ET

    My thoughts on the snow through Tuesday in the East and West.

  • Long Range Update into Mid-December

    November 20, 2015; 11:41 PM ET

    Other than a blast into western Canada next week, most of the Arctic air will remain north of the Arctic Circle into December with just brief intrusions while mild, Pacific air takes hold from west to east.

  • Weekly Long Range Update

    November 12, 2015; 11:39 PM ET

    The latest clues to the weather pattern over the next several weeks.

About This Blog

Brett Anderson
Brett Anderson covers both short-term and long-term weather and storm forecasts for Canada in this blog for