A “25-Day” forecast?

Heres’ a new one.

Accuweather will soon start issuing a “25-day forecast.”

That’s right, we’re talking a specific detailed forecast on temps, rain/snow etc 25 days in advance.

“AccuWeather.com released a 25-Day Forecast that can help users make informed decisions about long-term plans. The AccuWeather 25-Day Forecast shows you the trends in temperature, precipitation and more, along with the forecast for a particular day.

For each day in the 25-day Forecast, you can see the forecasted high and low temperatures, the AccuWeather RealFeel® temperature, sky conditions and chance of precipitation, wind speed and direction, rain, snow and ice amounts, thunderstorm probability, cloud cover and UV index.”

Source: Accuweather.com

Here’s the forecast for the Twin Cities. Notice there is no mention of rain Thursday, Friday, or Saturday.

16 accu.PNG

Source: Accuweather.com

Put me in the skeptical camp as to the value of this latest venture.

Forecasts beyond 5-7 days show little skill over “chance” or 50%. To put precip totals on a forecast 25 days out? Good luck with that.

The Washington Post’s Capital Weather Gang seems to agree with the notion that this is more of a headline grab, and less about weather science.

“No it’s not an April Fools’ joke: Accuweather is pushing the limits of weather forecasting and issuing detailed predictions extending 25 days into the future effective today.

Consider me highly skeptical about their value.

Nevermind, the skill in forecasts rapidly deteriorates beyond 5-7 days and is typically no better than judging what the weather will be based on climatology (historical averages). Today, AccuWeather delivers the forecast out to Saturday, April 28 to every zip code in the U.S.

For Washington, D.C. on 4/28, we should expect mostly cloudy skies with “showers around” and a high of 64 and low of 46. But don’t worry, if you buy this unrealistically precise forecast, just two hundredths of an inch of rain will fall – your outdoor picnic won’t be washed out.

Let’s get real for a second: I can hardly say with a lot of confidence whether 0.02″ is a good rainfall prediction for today much less more than three weeks from now.”

Source: Washington Post – Captial Weather Gang

What do you think? Do these kinds of forecast have any value to you as a user?


  • jon

    I’m sure it will work great in southern California.

  • Chris

    From the same folks that said we (they in Chicago) would want to move because of last winter. I know you are too nice to mention that.

  • Casey

    It’s the Field of Dreams theory of marketing. “If you build it, they will come…”

    If a 25 day forecast is as implausible as you and other meteorologists have indicated, there must have been an epic battle between the scientists and the marketing department, and once again, science loses. This is all about pageviews and advertising. Sad.

  • Erin

    As I’m planning for my 30th Birthday/Seminary Graduation party open house in a month and a half, I’d love to believe that this could be reliable. The decision of a tent would be a lot easier.

    I also live on earth and deal in reality, no matter anyone’s opinion of someone about to graduate from seminary.

    At this point, I’m already skeptical that MPR’s weather page, supplied by Weatherunderground, now provides two-week forecasts.

    I agree with the publicity stunt theories. Such forecasts remind me of reading my horoscope. It’s good for a laugh or a raised eyebrow, but not something on which to base important decisions.

  • Kurt

    Leave it to AccuWeather, the same folks that said tsunami debris caused our warm winter, to give us the fodder. As if the 10-day GFS didn’t provide me with enough uncertainty in my life… Want to know the best part? People will take this seriously and make plans based upon what AccuWeather is feeding them, and then get angry because it won’t be correct. The ONLY way to get a consistent forecast 25 days out is moving to Singapore, which I hear is delightfully tropical this time of year.