Sep 18, 2011

The LRC Versus The GFS; Let The Fun Begin

I've been designing several LRC analysis tools the past few months and recently put the final touches on a 500mb height trend tool that will forecast said trends and compare them against the forecasts of the 7-14 day GFS (Global Forecast System). I am hopeful this tool will aid in my learning and understanding of the LRC.

The guts of the tool begin with 3 basic steps; the ability to access daily forecast and observed 500mb heights, extraction of the data into a configurable format and the task of manipulating the data into a structured database. The rest then is up to the beholder. Admittedly, a large amount of work which has culminated into a very user-friendly interface.

At the moment I have two specifics I want to accomplish with this tool. One, provide a sense of confidence in acknowledging when the patterns begin to stray from their predessors. With the past years cycle currently morphing into a new cycle, following the cycle in this manner should do just that. Two, is to contend the GFS 14 day 500mb forecast accuracy with that of the LRC 500mb trend accuracy. A trend that is simply a total mean blend of prior cycle heights. This coming winter season will provide a perfect battle ground. Below is a graph representing the latest cycle forecast period. Incredible how the LRC predicted the latest geopotential height plunge while the 7-14 day GFS forecast failed to do so.

(Green Bay, WI 500mb Forecast using the LRC - Aug 8 thru Sep 26, 2001)

It is noticeable in the graph above that the actual 500mb numbers do not precisely follow the LRC trend. That fault is directly tied to my personal interpretation of the theory as I am using the average amount of days (50) between recurring features. A self interpolation of the trend is required.

I am excited for my sophomore year following the LRC and what will be learned about the cyclic patterns within our atmosphere. For the entire set of the 2010-11 LRC season 500mb height forecast graphs please click here. If there is an interest in learning how to use the tool or obtaining any other tool I used to build it, feel free to inquire. I will be more than happy to share and exchange ideas. It is conceivable that this tool can be used for any location that has the required data available.

If there are any questions or thoughts on my research and analysis of the LRC or how I presented the material just let me know in the comments section of the blog. Thanks for reading!


Tools (right click - save as)
- Daily 500mb Height Extraction
- GFS Forecast 500mb Height Extraction
- 500mbDailyForecast Dynamic Data & Charts

If there are any problems or questions let me know.


  1. Would love to play around with the tool this year. How do you link in the data?

  2. Ed, I will update the entry with links to downloads and instructions within the next day or so.

  3. I'm looking forward to your outcome product. A thought, I'm not sure everyone knows what GFS means or how it is computed. You may consider a note with description - a thought.

  4. Bob, I often fail to explain things in full. I appreciate your feedback and I think it's a great idea!