Today, the Curmudgeon launches a new service aimed at keeping the weather guys (and gals) honest.
This comes from a friend's challenge to the weather nerd in the Curmudgeon (hey, who else would look up the National Hurricane Center's forecast from last year to show how worthless it's forecast is for this year?).
Anyway, we'll just do this for just two weeks, at the bottom of each post. Our thesis is that the 10-day forecast is useless--not much better than random--and that the five day forecast is pretty marginal.
Here's how we'll do it: each day, we'll ask the question--what if I want to plan an afternoon outdoor activity from 1 pm to 6 pm in Arlington, Virginia in five days (inclusive of the current day) and in 10 days? If I relied on The Weather Channel's forecast, would I be disappointed?
If TWC forecasts a 50% or greater chance of rain for the date in question, the Curmudgeon will not schedule his activity; if it DOESN'T rain, then the forecast let us down. Conversely, if TWC forecasts less than a 50% chance of rain, we're going to schedule our outing; if it rains between 1-6, then the forecast let us down.
We'll also see if the temperature forecast is within =/- 5 degrees of the actual temperature for the date.
Each day will be rated as to whether the forecast was useful: Y=useful forecast; N=useless forecast.
Admittedly not all that scientific, but a realistic experiment on how people presumably use (or could use) long term forecasts.
So, how'd TWC do for today? We can only give you the five-day report. On Monday, June 5, TWC forecast a high of 83 today, with a 30% chance of scattered T-storms. Turns out that was pretty accurate. It reached 82 degrees today, and while we did get 1/100 inch of rain it wasn't enough to ruin any outdoor event between 1-6 pm. (It will be a few more days before we can give results for 10 days forecasts.)
Today's rating: Y.