Saturday, December 10, 2005

Time for some accountability

How about that snow, eh?

Although restraint has never been their strong suit, the local Weathermen seemed to keep this last storm into perspective, never really overstating things and, as you'll see, getting close to right.

We've all complained about how bad weather forecasts can be, but how bad are they really? No one seems to keep track of these things, except anecdotally (which doesn't pass muster in my camp--I need data).

Until now.

Welcome to the first installment of Hayduke's Weatherman Accountability feature. We'll run down the various predictions of the local "meterologists" and see how close they actually come to getting it right. I'll keep a running tally of the winner each week, and with any luck (and some good snow storms) we'll finally get some accountability in a field where it has long been lacking.

The predictions are from 11 pm on Thursday (before the snow started falling). I chose this time , basically, to give them the best chance of succeeding--and I figured this would be the last time most people paid attention to the weather; I, however, was busy monitoring it throughout the night at Hayduke's Weather Command Center.

Also, unless indicated, the predictions are for the Columbia area.

Baltimore Stations

  • WMAR-2 (ABC): 3” – 6” (provided by WeatherBug)
  • WBAL- 11 (NBC): 3” – 6” north of 95; 1" – 3" south of 95
  • WJZ -13 (CBS): 3” – 6”
  • WBFF-45 (Fox): 3” – 5” (provided by Accuweather)
Washington Stations
  • WRC-4 (NBC): 5” – 8”; 3"- 6" D.C. (see first map at the bottom)*
  • WTTG-5: 3” – 6”
  • WJLA-7: 3” – 6” (see second map at the bottom)*
  • WUSA-9: 1” – 4” Metro; 5” – 8” Frederick North;
National Forecasts
Accuweather: 3" - 5"
Weather Channel: 4" - 6"
National Weather Service: 4" - 6"

Now, how much did we actually get? Here's a hastily drawn map of the totals (hey, I'm a writer--it's the best I could do), and here's a link to the real one with cool little pop up windows.

As you can (maybe) see, Columbia's lawns Friday morning were covered with a little less than 3" of wet snow and sleet, which was the bottom limit of most predictions; admittedly, the sleet pushed down the accumulations, though almost all the Weathermen accounted for this. On the whole, though, pretty good.

But really, if we want to split hairs (and we do!), I'm saying most of these guys got it wrong. I say this in part because of a long standing grudge I have with them. See, they always hedge their bets on the high side, fearing that if something silly happens with one of these storms (it slows down, extra moisture comes in from the ocean/Gulf, whatever) it might drop more snow than expected. And if they, god forbid, underestimate a storm...well, I just can't let myself think about that. Unfortunately, the high predictions feed our mass hysteria over snow, which is past the point of lamentable and is instead just funny.

Anyway, I'm not letting them get away with such tactics this year. The map of totals above is pretty clean, by which I mean the "zones" of accumulations are well-defined and could have been predicted.

(Full disclosure: I'm totally just guessing on the "could have been predicted" stuff, though I'm guessing with common sense, which counts for something.)

The confidence intervals listed in the above forecasts don't match the zones very well; notably, Bob Ryan was pretty far off this time, not what you expect from a veteran like Bob. The only one with a "good" match, at least in my mind, was Topper and the Gang at WUSA-TV 9 in D.C. The prediction of 1 "- 4" metro was almost perfect and the 5" - 8" for Frederick and north wasn't bad.

Thus, after Storm 1**, Channel 9 is in the lead (this is sure to make Hayduke's friend, a Topper and Digital Doppler 9000 stalwart, a happy man). I'll give the rest a partial victory for skirting accuracy, except for Bob Ryan, who just didn't get it this time.

Feel free to debate your favorite forecaster's side in the comments.

*These are the only maps I could download online.
**I know this technically wasn't the first storm, but I just came up with the idea for this post last night. Plus, it's my blog and I can be arbitrary if I want.

UPDATE: Abbzug thinks the forecasters intentionally over-predict snowfall totals to drive up ratings for the local newscasts. I, however, respectfully disagree, thinking these fine men and women have more integrity than that.


ralston said...

I'm with Abzugg on this. Why would it be that the forecasters almost NEVER underestimate the amounts of snowfall? It's not like they say, "We think that the maximum we could get is . . . ." or "Although it's most likely that we'll get an inch, three inches is possible." Instead they say, "we expect that we'll have 6 inches of snow by this time tomorrow" (and we get one inch). I doubt that they are intentionally dishonest, but get caught up in the expectations, the hype, the desire to tell people what they want to hear, etc.

Hayduke said...

But they're all trained meterologists--scientists!--who should value accuracy over ratings. Right?

I've been known to be naive, however.

Anonymous said...

it also looks like Santorum and his buddies at Accu-weather were closest among the national guys with the beloved NWS coming up short....

Hayduke said...

We do not speak of Santorum on this blog...