Saturday, February 25, 2012

A Friendly Challenge to Local Forecasters

We challenge local Twin Cities forecasters to get creative and more informative in their forecast presentation as we get closer to a potential big storm on Tuesday/Wednesday. We’d love to see them take a page from the Capital Weather Gang book and paint a storm scenario in simple probabilities, something along the lines of this: 
  • 10% 1 inch or less
  • 25% 1-3 inches
  • 30% 3-6 inches
  • 25% 6-12 inches
  • 10% >12 inches
This seems to be a very logical way of recognizing the possibilities of a given storm scenario while implicitly incorporating the uncertainty that comes with distance (in time) to the event. And just as the cone of a possible land-falling hurricane gets narrowed as time elapses, so too, could the probabilities of various outcomes.

Forecasters, what are your thoughts with this kind of presentation? Consumers/weather watchers, is this a presentation you'd like to see?


  1. Bill - I would assume all the regulars to your site could handle and digest a probability forecast that you have mentioned. Would the main stream Mets be able to come up with this and explain it? I'm sure they could, but would the general public be able to handle it? Probably not.

    I know MSP is at around 18" of snow for the 2011-2012 season, or about the equivalent of the Dec 2010 Dome Buster storm. Not sure if anyone is keeping track, but I'm guessing our predicted amounts for the 2011-2012 48 hours out is closer to 40".

    If I were musically inclined I would be creating a song called, "If Only it Verifies", which seems to be the standard lexicon for some Mets to explain off-the-charts models for MSP snow potential that eventually heads north, south or into Never-Never Land.

    Maybe someone could help me with the lyrics...

    Looking out 4 days.
    What do I see?
    2" of QPF.
    It must be a dream.
    If only it verifies...
    ...what a storm it would be.

  2. I'd at least prefer that for "long" term forecasts.

    Something like this until 24 to 36 hours before the storm.

    Chance of at least 4" - 85%
    Chance of at least 8" - 35%
    Chance of at least 12" - 10%

    I think they try to nail down amounts too soon and it backfires.

  3. Isn't this kind of what the NWS does with its winter weather snow forecasts? Probability of 4 inches - 10/40/70%, etc...

  4. Bill:
    Personally, I can't stand the words chance, maybe, might, could, etc. I feel that I weather forecaster needs to be confident no matter how murky the situation. I believe most of the general public understands that weather forecasting is highly variable and that your forecast will change with time. With that being said, I can't stand using percentages because very few people are good at creating them and the public considers 50% as a cop out.