Thursday, March 21, 2013

Winter Weather

Oh hi! Didn't see you there.

It is now spring! And despite the massive continuous blizzard that appears to be going on outside, we're supposed to be getting warmer. Any day now...

You may have seen my analyses of Summer and Fall for Edmonton weather. Hopefully ever since then you've been on the edge of your seat awaiting the results for winter.

Wait no longer! The winner for winter is: The Weather Network. (three times in a row!)

Scores for winter (out of 100):
Noteworthy about these scores is that Environment Canada climbed from 5th place to 3rd place for the winter, and that everyone's scores (apart from Environment Canada's) continued to decrease from the fall. This is all shown in this graph:

Weather or not (PUN!) temperatures and precipitation are actually tougher to forecast in winter is a question better asked of the actual meteorologists. My suspicion is that at least part of the continued decrease in scores is that trace levels of snow are harder to measure as precipitation than rain, but that's mostly just a guess.

Some fun facts!

Best high temperature prediction: Weather Channel 1-day prediction: 71.84%
Best low temperature prediction: Weather Network 1-day prediction: 68.64%
Best precipitation prediction: Weather Network 1-day prediction: 76.67

Worst high temperature prediction: 6-day prediction: 36.30%
Worst low temperature prediction: 5-day prediction: 37.64%
Worst precipitation prediction: Environment Canada 6-day prediction: 54.70

Some graphs!

Again, CTV scores are only directly compared to the others for four days. I still find it cool that there is as strong of a downward trend as there is - on average, a forecast for a week in the future is 15% less accurate than a forecast for tomorrow.

For those of you who are still reading and like graphs, you can check out the breakdown of where the previous graph comes from:

Have a good spring!


Adam Lohonyai said...

From my water and ice engineering courses, I know that the gauges used to measure snowfall tend to be much less accurate than for rainfall.

Brad said...

Is there anywhere I can look to see what exactly your methodology is? Particularly how you verify POP, especially when no POP is given (e.g. EC past Day 2).