How They're Graded. Just as weather prognostication is as much art as science, so is the grading system for our fearless local weathermen and weatherwomen. A perfect performance is very hard to achieve. For a snow event such as the one just concluded, the criteria include : 1) early identification of a potential storm, 2) preliminary assessment of the storm's magnitude, 3) accurate identification of onset, particularly when a rushhour is involved, and 4) accuracy in snow accumulation forecast for the immediate Minneapolis/St. Paul area.
Here are the report cards for the historic snowstorm of Dec. 10-11, 2010, for which 15-20 inches of snow were recorded in most locations.
WCCO (4): B. There was nothing particularly notable about WCCO's performance. It was generally in the middle of the pack.
KSTP (5): B-. KSTP's critical mistake was their Thursday night forecast, which projected the snow to fall just prior to the Friday evening rushhour. Viewers that followed their advice could have made unnecessary changes to their Friday evening plans. Their final snow projection of up to 18 inches was essentially accurate.
KMSP Fox9 (9): C+. Fox9 was the first to project that snowfall amounts would be higher on the south side of the Twin Cities. However, their 10 to 14-inch projection lagged actual totals by about five inches. (An aside: Ian Leonard said on the 9 p.m. news on Saturday that "we weren't far off on our projections from several days ago." Not so. Twenty-four hours before the storm, they were forecasting 6 to 10 inches, a far cry from what actually fell. Graders frown on attempts to self justify, particularly when plain wrong.)
KARE11 (11): C. KARE was consistently a step behind on the escalating snow forecast and never truly caught on to the full "epicness" of the storm. KARE is typically not one to proclaim big headlines such as "blizzard" and "historic," but in this case that would have been appropriate.
Star Tribune/Paul Douglas: B+. As with all other weather outlets, PD initially didn't see the large potential of this storm; however, PD was the first to recognize that the storm could be more than "a few inches." From that point, PD did an admirable job tracking the storm and its potential with the exception that he anticipated the highest snow amounts to be on the northwestern side of the metro. Still, his 15-20 inch forecast was right on target.
National Weather Service: B- The official forecast of the NWS was sometimes difficult to determine as information in their text forecasts was somewhat different than the verbiage contained in their special statements and warnings. However, what seemed to be their official forecast was 13 to 16 inches, not too far off from actual.
The next potential snow system appears to be Wednesday. Check back early and often to monitor the forecasting progress of Twin City weather gurus.
Looks like you forgot MPR. They nearly nailed the range of 10" to 20" in the metro.
ReplyDeleteAll in all, I think that you were fair. Ideally, weather forecasters won't worry about being graded by anyone but their peers. This was a dangerous storm and the difference between sensationalism and emphasizing the worst case scenario, should not have made any forecaster second guess themselves.
ReplyDeleteThis concept of inches of snow is somewhat worthless, snow quality and water content are what really matter. Of course, today with the drifting I would prefer to use feet or fractions thereof. An almost three foot high drift in my driveway kept me at the house after the 4WD allowed me to back out and get stuck.
Yes, that was brought to my attention. I'll include it next time.
ReplyDeleteAgreed, David. And ideally, weather -- and the people who present it -- wouldn't be as much of a media/ratings-fetching commodity as it seems to be today.
ReplyDeleteThis is an interesting exercise -- and a good forecast on which to base it given that the magnitude caught many of us at least a little off guard.
ReplyDeleteIdeally, yes. Science and technology aside, it's really up to mother nature in the end.
ReplyDeleteSeems like it was an objective summary. Meteorologists may not typically be concerned about public opinion of their approach to science, but when they are communicating direct to consumers, they ought to be. Not much different than all of the ratings around physicians, for example.
ReplyDelete[...] This post was mentioned on Twitter by Andrew L. Meyer and Andrew L. Meyer, Kathy Jerzak. Kathy Jerzak said: RT @aloumeyer: aloumeyer Interesting: Individual media forecasts graded for #snowmageddon. http://tinyurl.com/2f9pkg4 #blizzardpeople ... [...]
ReplyDeleteThis is sweet, I've been looking for a site that does comparatives on accuracy. Thanks!
ReplyDeleteGlad you like the site. It's not particularly scientific, but it's an honest effort to get at least some sense of how they do.
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