Those not prone to geekery, please stop reading now.
For each of the three local weather sources, two television stations and weather.com, I wrote down their forecast for the next seven days, including the current day, for both the high temperature and conditions. Eventually the conditions were broken down into Sunny, Partly Cloudy/Partly Sunny, Chance of showers/snow or scattered rain/snow or part day rain/snow, and Rain/Snow. There was a slight bit of human element in converting the various phrases for each source to these categories ("Partly Sunny with Scattered Thunderstorms" becomes, um, "Chance of Showers"). The day after I would get the conditions and high temperature from Weather.com.
The analysis was in two parts.
Temperature: One point was given for every degree they were off on their forecast seven days away, two points for every degree they were off on their forecast six days away, three points... etc.
Conditions: I gave much more weight to conditions then temperature. If they say it's going to rain in three days and you change your plans, well, that's much more serious than if it was four degrees warmer than forecast. Each of the assigned conditions were given a value based on severity - 1 point for Sunny, 2 for Partly cloudy, etc. The difference between the forecast condition value and the actual condition value was then multiplied by five for the seven day forecast, ten for the six day forecast, fifteen for the five day forecast, etc. The logic of this is that if they are wrong on conditions a week from now, well, no big deal. If they louse up tomorrow's forecast then someone needs more training.
The lower the number the better the forecasting abilities. Make sense? Should I get a life?
I found that my previously preferred source was the worst of the bunch. ACK!
WANE TV - 325
Indiana News Center - 277
Weather.Com - 273
Admittedly, this is only based on six full days of data and a handful of partial days. I intend to analyze a two week span soon. Results will be posted.