Author Topic: AccuWeather unveils 45-day forecast (I wish I were kidding) UPDATE: It's a dud  (Read 1372 times)

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Offline jmyrlefuller

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http://www.myfoxdc.com/story/23057797/accuweather-unveils-45-day-forecast

August 6, 2013

Temperature and precipitation trends in AccuWeather's 45-Day Forecast can help with Labor Day weekend, back-to-school and fall football planning.

AccuWeather Expert Senior Meteorologist Alex Sosnowski said that people should not use long-range forecasts as a strict guide but rather look at how the weather patterns evolve.

Temperature and precipitation trends in AccuWeather's 45-Day Forecast can help with Labor Day weekend, back-to-school and fall football planning.

AccuWeather Expert Senior Meteorologist Alex Sosnowski said that people should not use long-range forecasts as a strict guide but rather look at how the weather patterns evolve.

Drier and warmer spells versus cooler and wetter periods can be spotted in the AccuWeather 45-Day Forecast. Weather trends can be observed by watching how far above or below normal temperatures are expected to be and by following the chance of precipitation and precipitation amounts.

Each day in the AccuWeather 45-Day Forecast includes the forecast high and low temperatures, the patented 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.

Along with the forecast, historical information, such as normal temperatures, records and temperatures recorded one year ago, is provided.

If the 45-Day Forecast shows an expected high of 85 degrees and sunshine for Labor Day, the normal high for the date is 80 degrees and the record high for the date is 98 degrees, a lot of information can be gathered. Conclusions such as "an outdoor BBQ or swimming should be fair game" can be made.

Or, if you are planning a tailgate for a college football game and the 45-Day Forecast shows a trend of below-normal temperatures and rain on the date, you might want to plan ahead and invest in a canopy and heaters.
« Last Edit: October 09, 2013, 06:03:42 PM by jmyrlefuller »
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Offline jmyrlefuller

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #1 on: August 06, 2013, 09:00:15 PM »
Keep in mind... typical weather forecasts only have any degree of accuracy out to about 10 days. The models start getting off timing after about 5 days and spurious events (such as storms and fronts that never happen) start showing up at 11.

Now, granted, there are a couple of experimental models that are being developed that could realistically push the forecast range out to 14 days, maybe slightly longer. However, the idea that weather can be predicted, with any semblance of accuracy, beyond that-- especially a whopping month and a half-- is a fool's notion. Even the most accurate long-range model in use by the U.S. government, the state-of-the-art CFSv2, only advertises viable accuracy out to 17 days.
"Just because people in positions of authority are stupid, it doesn’t mean you have to go along with it." —Arlo Guthrie

Offline Oceander

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #2 on: August 06, 2013, 09:37:04 PM »
This is just nuts.  And quite honestly, I have the Accuweather doodad on my android smartphone and it is routinely wrong.

Offline alicewonders

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #3 on: August 06, 2013, 09:37:26 PM »
But...but...what about the Farmer's Almanacs?
Don't tread on me.   8888madkitty

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Offline jmyrlefuller

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #4 on: August 06, 2013, 10:04:02 PM »
This is just nuts.  And quite honestly, I have the Accuweather doodad on my android smartphone and it is routinely wrong.
They really are one of the worst.

When I was in college for meteorology, we had to do short-term forecasting as part of the class (I've been forecasting ever since, although now I'm working on the longer ranges-- as I said, I can get out to 10 now and I'm hoping the newest models can help me get decent results up to 14 days out now). Every so often I would compare the results I got with places like the National Weather Service, Weather Channel and Accuweather. The NWS and Weather Channel were OK... I won't say good, and certainly not as good as a live meteorologist, but OK. (Pretty much any forecast you get from a site like that is generated by machine and tweaked by meteorologists. The NWS uses meteorologists at each bureau to do their tweaking, while the commercial services all do it from one team at one location.) Accuweather, on the other hand, wasn't even in the ballpark a lot of the time.

There's a reason I, and so many others, call the place Inaccuweather.
"Just because people in positions of authority are stupid, it doesn’t mean you have to go along with it." —Arlo Guthrie

Offline jmyrlefuller

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #5 on: August 06, 2013, 10:09:02 PM »
But...but...what about the Farmer's Almanacs?
Fun reading-- I usually get one or two each year, and the first one of the season (Harris's) came in just a few days ago-- but the forecasts tend to not be particularly accurate. I think someone did a study on it showing that it's either not really any more accurate than random chance or too hopelessly vague to draw any real conclusions.

Still, the astronomy, tide tables and calendar features make it a worthwhile read, and some of them have very good articles.
"Just because people in positions of authority are stupid, it doesn’t mean you have to go along with it." —Arlo Guthrie

Offline alicewonders

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #6 on: August 06, 2013, 10:32:56 PM »
Thanks for the info, I find the almanacs are right about half the time but I enjoy reading them too.   888catlicking
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Offline DCPatriot

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #7 on: August 07, 2013, 07:03:54 AM »
LOL!.....it appears that computer processors have gotten so fast that they can input gazillions of previously saved weather patterns to the point that their so-called predictions are at least better than playing the lottery.
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Offline jmyrlefuller

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Re: AccuWeather unveils 45-day forecast (I wish I were kidding)
« Reply #8 on: August 07, 2013, 06:55:17 PM »
http://m.washingtonpost.com/blogs/capital-weather-gang/wp/2013/08/06/accuweather-you-cannot-be-serious-new-45-day-forecasts/

Accuweather: You cannot be serious.
by Jason Samenow
August 7, 2013

Accuweather calls its new 45-day weather forecast launched Monday “revolutionary.” I call it a joke.

By and large, weather forecasts beyond 7-10 days in the future simply do not have “skill.” That is, they provide no more accurate information than the historical average conditions in that time horizon.

AccuWeather insists it is innovating and pushing the envelope by providing these forecasts. In its press release, it boasts of being a leader in long-range forecasting.

In reality, it is simply peddling a useless product to people who don’t know better.

Let’s examine one of AccuWeather’s own scenarios demonstrating the supposed usefulness of the 45-day forecast, published in an article on its Web site:

If the 45-Day Forecast shows an expected high of 85 degrees and sunshine for Labor Day, the normal high for the date is 80 degrees and the record high for the date is 98 degrees, a lot of information can be gathered. Conclusions such as “an outdoor BBQ or swimming should be fair game” can be made.

The claim that the 45-day forecast is providing value-added information in this case is ludicrous. For one, you don’t need a 45-day forecast for Labor Day to know that Labor Day weather is usually warm and occasionally hot. All you have to do is look-up the averages and records. And, while occasionally long-range forecasts can give you a credible sense as to whether temperatures will be above or below normal, they cannot – under any circumstance – provide accurate information about whether it will rain or not.

Getting the timing specifics of storminess right even a few days into the future is incredibly challenging. 45 days into the future it’s impossible.

It is incredibly misleading for AccuWeather to imply its long-range forecasts can help planners – whether it be for a wedding or outdoor sporting event – determine whether and when to hold their event.

I’m not the only one who feels this way.

As a refresher, let me revisit some of the reactions from some of CWG’s senior meteorologists when AccuWeather launched the 25-day forecast in 2012:

Wes Junker, CWG’s winter weather expert, with over 30 years of forecasting experience said: "It gives people a false sense of where the science is. [In daily forecasts], there's no accuracy beyond 7 days at all. You can't tell the day the storm is going to be [beyond 7 days].”

Steve Tracton, who holds a Ph.D. in meteorology from MIT, said: “It undermines the credibility of the science of meteorology. There cannot be skill at those ranges – it goes back to chaos theory."

When AccuWeather launched its 25-day forecasts in 2012, I tracked their accuracy in Washington, D.C. over a period of 30 days (April 28 – May 28, 2012). I found, not surprisingly, that its temperature forecasts 25 days into the future were no better historical averages – about 6 degrees off for both the high and low temperatures. On 6 of the 30 days, it had forecast errors exceeding 10 degrees for high temperatures.

Its rainfall forecasts were also problematic. It predicted rain on just 7 of the 14 days rain actually fell. The day it rained the most (1.22″ on May 15), it predicted no rain or “clouds and sun”.

To my knowledge, AccuWeather has never (in the last 10 years at least) published a rigorous analysis of how (in)accurate its forecasts are – which isn’t a particularly transparent approach for the company, given its name.

Instead, it serves up press release propaganda.

“The [45-day] forecast is the result of extensive scientific research and is backed by more than 110 meteorologists, providing the public with the Superior Accuracy they count on from AccuWeather,” says Steven Smith, AccuWeather’s Chief Digital Officer.

I fully appreciate AccuWeather’s desire to be on the cutting edge of weather forecasting, but doing so just because it can and because some of its customers may like it, doesn’t make it worth doing or valuable.

If AccuWeather wanted to innovate responsibly, rather than providing forecast details out to 45 days, it could provide some very general information about the direction of weather trends at this range. For example, it could list historical averages at long range complemented by colorful, easy-to-interpret graphical symbols to indicate whether temperatures and precipitation were favored to be above or below those averages. It could also provide confidence indicators, which would educate its customers about the lack of certainty in longer range forecasts.

But instead, AccuWeather has chosen to extend its scientifically-lacking approach, which is impossible for me to defend and will continue to be the subject of ridicule among meteorological peers.
"Just because people in positions of authority are stupid, it doesn’t mean you have to go along with it." —Arlo Guthrie

Offline jmyrlefuller

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UPDATE: It's a dud.
« Reply #9 on: October 09, 2013, 06:02:58 PM »
http://m.washingtonpost.com/blogs/capital-weather-gang/wp/2013/10/08/accuweathers-45-day-forecast-fails-to-impress-in-multi-city-test/

AccuWeather’s 45-day forecast fails to impress in multi-city test
by Dennis Mesereau
October 8, 2013

Back in August, AccuWeather launched an ambitious feature on their Web site that let users view a 45-day forecast for any location in the United States. To the under-informed weather consumer, this sounds like an amazing feat, but CWG's chief meteorologist Jason Samenow summed it up pretty well soon after their announcement: it's a joke.

I kept a spreadsheet for three cities that compared AccuWeather's 45-day forecast to the actual observations for each day during that time period, and the results were unsurprising: their forecasts were, by and large, off the mark. Most of the time they weren’t even “somewhat accurate” according to my criteria.

The discipline of meteorology is far from an exact science. For the most part, the field is about the art of understanding a fluid atmosphere and using its past movement to predict what it will do in the future. Predicting the future is surprisingly hard, regardless of how easy Miss Cleo made it look.

Weather models do a relatively good job at helping meteorologists predict what the weather will do three to five days in advance, but anything beyond 7 days is stretching the limits of accuracy and science. As CWG meteorologist Dr. Steve Tracton was quoted in Jason's post back in August, AccuWeather's hyper-extended forecasts "[undermine] the credibility of the science of meteorology. There cannot be skill at those ranges - it goes back to chaos theory."

AccuWeather, for its part, argued in an August 7, 2013 blog post that the long-range forecasts aren't intended as strict guides, but rather as a reference point to judge if the weather will exhibit trends of warmth, coolness, or if there will be an extended period of rainy weather. However, their Web site conveys the exact opposite intention by publishing very specific forecasts. For example, AccuWeather's forecast for Washington, D.C. on November 8 (41 days out as of September 30, 2013) is "Cloudy; a shower or thunderstorm in spots in the evening, then late-night showers and thunderstorms."

That's not a trend, that's a guess masquerading as a scientific forecast.

Since AccuWeather appears to be presenting these "trends" as actual forecasts, I decided I'd put them to the test.

Evaluation of AccuWeather 45-day forecast: method

When I took weather forecasting courses while completing my meteorology minor at the University of South Alabama in Mobile, the meteorology department used a grading rubric to grade how well (or poorly) your forecasts performed when compared to the actual observations in the city for which you developed a forecast.

I adopted a very loose version of the meteorology department's grading rubric to judge AccuWeather's hyper-extended forecasts. It's rather simple:

    AccuWeather gets 1 point for every 1 degree Fahrenheit they're off on the high and low temperatures. If they predict a high of 70, and the actual high is 68 (or 72), they get 2 points.
    AccuWeather gets 1 point for every 10% they're off on the rain chances. If they predict a 20% chance of rain and it actually rains, they get 8 points. On the other hand, if they predict a 70% chance of rain and it doesn't rain, they get 7 points.

I chose these two variables (temperature and rain chances) because that's usually what most people care about when they check the weather. A score of 0 points means that AccuWeather got the high temp, low temp, and rain chances spot on. The more points they get on a certain day, the more inaccurate their forecast was.

By my criteria, a score of 15 indicates an inaccurate forecast, 25 extremely inaccurate, and 40 embarrassingly inaccurate. Between 5 and 15, a forecast is in a somewhat accurate-inaccurate gray area.

Starting on August 7, I recorded their 45 day forecast for three cities in the United States through September 20. The three cities I chose were Mobile, Alabama (KMOB); Denver, Colorado (KDEN); and San Francisco, California (KSFO). I chose Mobile and Denver because both cities have notoriously fickle weather and can present a challenge to forecasters. The third city, San Francisco, was chosen because of its reputation for extremely stable and predictable weather most of the year.

It's worth noting that this was not by any means a scientific study, but rather a direct observation of AccuWeather's forecasts compared to the actual weather recorded for each day. The project was done for illustrative purposes. In the cases I reviewed, AccuWeather's long-term forecasts were not only less than accurate, but also regularly failed to capture general trends in weather.

Evaluation of AccuWeather 45-day forecasts: results

Mobile

Starting with Mobile, Alabama, the forecasts were generally less than “somewhat accurate” – but not at the “embarrassing” level – throughout the 45-day period.

Showers and thunderstorms on the northern Gulf Coast are almost a daily occurrence from May until October. The observations at Mobile Regional Airport reflected the hit-or-miss quality of the storms in the area, recording at least a trace of rain 21 out of the 45-day period. AccuWeather did what most forecasters would do by playing it safe on rain chances, usually predicting between a 40-60% chance of rain each day through the period. Given that it rained on nearly half of the 45 days in the forecast period, they were in the ballpark about half of the time.

They missed the mark on the temperatures, though. Towards the end of August and through the middle of September, Mobile experienced a warm spell. Even as temperatures topped out above average each day during the first half of September, AccuWeather predicted the exact opposite.

Denver

The extremely unusual weather in the Mile High City over the period wreaked havoc with AccuWeather's 45-day forecast. The deluge experienced in eastern Colorado in the middle of September ran completely against AccuWeather's forecast of a dry spell during the same time frame. The forecasters were so confident in Denver not seeing a drop of rain that they issued a 0% or 1% chance of rain almost the entire week that the region saw historic flooding.

Denver experienced a heat wave for a week and a half before the "biblical" rains struck, again almost diametrically opposing AccuWeather's forecast of a general cool spell followed by average temperatures.

Also, the company's forecast of 73 degrees on August 20 was blown away by the actual high of 99 degrees, a 26 degree difference. Similarly, they predicted 72 degrees on September 3, falling 22 degrees short of the actual high of 94.

Overall, after the first week of the 45-day period, the forecast performance hovered in the extremely inaccurate range and, at times, reached embarrassing levels.

San Francisco

San Francisco is famous for having mild weather all year with little variation from climatological means. The city saw virtually no rain during the period, which AccuWeather predicted fairly well, getting it wrong only on the two days it actually rained (predicting a 4% and 2% chance each day, respectively).

The temperature forecasts were mixed.

They were generally in the ballpark when it came to high temperatures, predicting trends relatively well when one excludes the abnormally toasty high of 88 degrees on September 7. The low temperature predictions, on the other hand, were mostly wrong. The company predicted below-average temperatures through almost the entire period, which was the opposite of what actually occurred.

In general, AccuWeather’s forecasts in San Francisco fell somewhere between somewhat accurate and inaccurate.

Evaluation of AccuWeather 45-day forecast: conclusions

Overall, AccuWeather's 45-day forecasts were inconsistent: occasionally right, often in the gray area between somewhat right and wrong, and occasionally spectacularly wrong. They missed key trends as often as they picked up on them.

In my limited sample, the forecasts did not get worse with time but suffered similar deficiencies whether it was day 5 or day 45. The company might want to spin this as evidence that their 45 day forecasts somewhat resemble science, but, in my view, it’s poor forecasting consistently performing poorly.

AccuWeather is a for-profit company and they have every right to pass off less-than-accurate forecasts as they wish, but the public deserves to know that these 45-day forecasts are not rooted in any science currently available to meteorologists and have not demonstrated value. Caveat emptor.

NOTE: There are some good graphs in the link that show just how far off Accuweather's forecasts were. ~JMF
"Just because people in positions of authority are stupid, it doesn’t mean you have to go along with it." —Arlo Guthrie

Offline Oceander

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I have AccuWeather's widget on my phone and I have to say that it's really unreliable; I prefer the Weather channel app.


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