As a career I couldn't even imagine how un-rewarding it is - you could pour hours and hours into developing new algorithms that only get tiny increases in accuracy due simply to the massive complexity of the system you're trying to model. When you're right people take you for granted, and when you're wrong you take a lot of blame.
That being said, a while ago I noticed that sometimes different weather forecasters will predict radically different weather for the same day, given the same data. Also, I noticed that on Monday the weather for the weekend could be substantially different than the forecast from Friday. These are all fair differences - tweaks to models could cause differences of opinions between meteorologists, and the closer your prediction is to when you make it, the more accurate we'd hope it would be.
I was curious as to how much of a change there would be, though, which is why I decided to keep track of it. Since the beginning of June I've kept track of the six-day forecasts for High temperature, Low temperature, and Probability of Precipitation for five different forecasting stations: timeanddate.com, Environment Canada, Global Weather, the Weather Network, and the Weather Channel. Environment Canada, Global, and the Weather Network were chosen based on the sites visited most frequently by myself and my friends, the Weather Channel was chosen as it is the basis of Yahoo! weather, and subsequently the commonly-used Apple weather app, and timeanddate.com was chosen because it's a large multinational site. All stations were chosen at the Edmonton downtown location, not the international airport, and data for predictions was collected between 11 and 12 am for consistency in comparison.
Now that summer's over, I have some preliminary results. And the winner (by a hair) is the Weather Network!
Score (out of 100):
- Weather Network: 66.92
- Global Weather: 66.02
- Weather Channel: 63.99
- Environment Canada: 55.00
- TimeandDate.com: 54.25
Some fun facts!
Best High temperature prediction: Weather Channel 1-day prediction (96.79% within 3 degrees)
Best Low temperature prediction: Environment Canada 2-day prediction (96.07% within 3 degrees)
Best POP: Global 4-day prediction (p-value 0.346)
Worst High temperature prediction: TimeandDate 6-day prediction (55.20% within 3 degrees)
Worst Low temperature prediction: Global 6-day prediction (68.57% within 3 degrees)
Worst POP: TimeandDate 3-day prediction (p-value 0.038)
So there you go! Hopefully this helps you the next time you're planning a picnic (or whatever people check the weather for...).