I Think I've Made My Point....

...regarding AccuWeather's inaccurate forecasting, but I'll end this little analytical experiment with the results for 8/1 and 8/2 (forgot to post yesterday's results).

8/1 - 80 - 84 - 78 - 79 - 79 - 84 - 93 - 94 - 96 -

8/2 - 76 - 79 - 82 - 88 - 86 - 84 - 97 - 94 - 95 -

And the real temperatures? 8/1 topped out at 83° thanks to some unexpected cloud cover and a surprise rainstorm. 8/2 came in at 89° and sunny.

Now take a look a the forecasts. There was a a 17° spread in the 8/1 forecasts and a 19° spread in the 8/2 forecasts The closer we got to the actual date, the more inaccurate the forecast was; in these cases, they actually had two days' worth of guesses that were pretty close, but they seem to be just that--random guesses that they abandoned a day or so later.

If you ask me to guess your age and I start throwing out years in a 17 to 19 year range, odds are I'll get it right at one point or another, but I'm not going to be dishonest enough to claim that there's a science to this system. Too bad AccuWeather isn't so frank about their weather guesswork.

InAccuWeather

Another day, a lot more missed forecasts.

Today's high was 87 (in fairness, it might have gone higher had a cloud front and scattered rain not moved in at about 2:30, dropping temperatures into the low 80s and the high 70s for the last part of the afternoon). Here's what AccuWeather forecast for today:

80 - 83 - 95 - 91 - 94 - 94 - 94 - 95 - 96

And once again, the actual high was very, very near the midpoint of the lowest high forecast and the highest high forecast--and once again, AccuWeather never once forecast this as the high. The shotgunned all around it, but thus far not a single one of their forecasts has been accurate. Not one.

Pretty pathetic, isn't it? And these guys have the audacity to include "Accu" as part of their name...

More Forecasting Folly

July 29th came and went, and with it came a high temperature of 87 degrees once again ( I thought it would get up to 88, but some afternoon clouds held us at the 87 mark). So what were AccuWeather's forecasts for 7/29?

80 - 84 - 92 - 93 - 93 - 93 - 92 - 94

Once again, their forecasts ran the gamut from 7 degrees too low to 7 degrees too high--but never once did they forecast 87. Even more interesting, they get no better at weather forecasting as the date gets closer. They're just as far off a day or two before as they were a week earlier... just in the other direction.

Must be nice to have a job in which the only accuracy you display is in your trademarked company name...

More Meteorology

I'm aware that some of you are horribly bored by this, but rest easy--I'll be done with this weather stuff in a few days. I just want to see if my suspicion is correct and AccuWeather's 15-day forecast is nothing more than random guesswork.

Now let's look at the forecasts as of 7/26 (I'm not posting 'til 7/27, but I did a text capture of these in mid-afternoon Tuesday).

7/27 - 95° (2° higher htan yesterday)
7/28 - 92° (2° higher than yesterday)
7/29 - 92° (1° cooler than yesterday)
7/30 - 95° (2° warmer yesterday)
7/31 - 95° (2° warmer than yesterday's forecast)
8/1 - 94° (1° higher than yesterday's forecast)
8/2 - 94° (3° cooler than yesterday's forecast!)
8/3 - 90° (3° higher than yesterday's forecast)
8/4 - 77° (6° cooler than yesterday's forecast--and where di these 70s come from?)
8/5 - 82° (4° warmer than yesterday's forecast)
8/6 - 83° (7° cooler than yesterday's forecast)
8/7 - 87° (1° cooler than yesterday's forecast)
8/8 - 88° (1° warmer than yesterday's forecast)
8/9 - 92° (a very hot forecast for 15 days out--surprising!)

Tomorrow I'll actually compare the 7/27 forecasts for the last week or so with the real temperature and see how far-ranging their forecasts were, and when they were closest to the real temperature.

Weather or Not You're Interested

Another day's worth of Accuweather forecasts; with 7/27 only two days away, they're starting to settle in on a more specific forecast, but there's still time for them to change everything.

7/27 - 93° (same as yesterday)
7/28 - 90° (2° cooler than yesterday)
7/29 - 93° (same as yesterday)
7/30 - 94° (same as yesterday)
7/31 - 92° (2° cooler than yesterday's forecast)
8/1 - 93° (9° higher than yesterday's forecast)
8/2 - 97° (13° higher than yesterday's forecast!)
8/3 - 87° (11° higher than yesterday's forecast)
8/4 - 83° (3° higher than yesterday's forecast)
8/5 - 78° (9° lower than yesterday's forecast)
8/6 - 90° (3° higher than yesterday's forecast)
8/7 - 88° (wow--there are no cool temperatures in AccuWeather's forecasdt, which is a first!)
8/8 - 87° (another aberration for AccuWeather--the cool day comes 12 days out, not 15)

More Meteorology

Another day of AccuWeather forecasts... and as I had predicted ahead of time, as we get closer to 7/27 (the first day I began tracking in my blog posts), the warmer the forecast is. Here are today's forecasts for 7/27 through 8/7:

7/27 - 93° (same as yesterday)
7/28 - 92° (same as yesterday)
7/29 - 93° (same as yesterday)
7/30 - 94° (same as yesterday)
7/31 - 94° (11° higher than yesterday's forecast)
8/1 - 84° (5° higher than yesterday's forecast)
8/2 - 84° (2° lower than yesterday's forecast)
8/3 - 86° (same as yesterday)
8/4 - 80° (same as yesterday)
8/5 - 87° (10° higher than yesterday's forecast)
8/6 - 87° (11° higher than yesterday's forecast)
8/7 - 88° (wow--there are no cool temperatures in AccuWeather's forecasdt, which is a first!)

More on Not-so-Accu-Weather

Okay, another day has passed, and here's the Accuweather forecast for 7/27 through 8/6. Notice that once again, there are very cool temperatures forecast at the end of the 15-day period.

7/27 - 93° (2° lower than yesterday)
7/28 - 92° (same as yesterday)
7/29 - 93° (same as yesterday)
7/30 - 94° (3° higher than yesterday's forecast)
7/31 - 83° (6° lower than yesterday's forecast)
8/1 - 79° (same as yesterday's forecast)
8/2 - 86° (2° lower than yesterday's forecast)
8/3 - 86° (same as yesterday)
8/4 - 80° (9° lower than yesterday's forecast)
8/5 - 77° (9° lower than yesterday's forecast--and once again, there are very cool temperatures at the end of the forecast period)
8/6 - 76° (AccuWeather's wondrusly cool 15-days-out forecasts return!)

More Forecasts, Weather You're Interested or Not...

And here we are, one day later and ever-closer to 7/27, when we'll see which of AccuWeather's many divergent forecasts is the proper one. In the meantime, let's see how their forecasts have changed from yesterday:

7/27 - 95° (1° higher than yesterday, 9° higher than Wednesday's forecast)
7/28 - 92° (a1° down from yesterday)
7/29 - 93° (1° higher than yesterday, 9° higher than Wednesdays forecast--notice the AccuWeather trend to promise cool temperatures, then continue to push them back?)
7/30 - 91° (4° lower than yesterday's forecast, 11° higher than Wednesday's forecast!)
7/31 - 89° (8° higher than yesterday's forecast)
8/1 - 79° (1° higher than yesterday's forecast)
8/2 - 88° (6° higher than yesterday's forecast, 10° higher than Wednesday's)
8/3 - 86° (10° higher than Wednesday's forecast!)
8/4 - 89° (3° higher than yesterday's forecast)
8/5 - 86° (don't worry, that forecast will increase as the date gets closer)

When 7/27 gets here, we'll also look at their forecast trend for that date and see how far-ranging their forecasts were.

More Not-So-Accu-Weather Stats

Continuing to monitor the incredibly changeable Accuweather weather forecasts for Marietta, just to investigate my hypothesis that not only are their 15-day forecasts inaccurate, they're also totally inconsistent with their own forecasts as each day passes.

7/27 - 94° (same as the adjusted forecast from yesterday, 8° higher than Wednesday's forecast)
7/28 - 93° (a sudden 8° forecast jump from yesterday)
7/29 - 92° (an 8° forecast jump from yesterday--gee, the cool weather forecast is fading away!)
7/30 - 95° (12° higher than yesterday's forecast, 15° higher than Wednesday's forecast!)
7/31 - 81° (4° lower than yesterday's forecast, 1° higher than Wednesday's--and as I had mentioned before, the cool weather is always lurking at the end of the 15-day forecast window)
8/1 - 78° (6° lower than yesterday's forecast, 2° lower than Wednesday's forecast)
8/2 - 82° (3° higher than yesterday's forecast, 6° higher than Wednesday's)
8/3 - 83° (7° higher than yesterday's forecast!)
8/4 - 86° (well, at least there's not danging the mid-70s meteorological carrot before us 15 days out)

And this all tends to support my theory that there isn't the slightest bit of accuracy and/or science to a 15 day forecast--pure guesswork, apparently. And with temperature swings as much as 12° in the forecast temps for the same date, no matter what the weather is, they can point to one of their guesses and claim it was right.

No-So-Accu-Weather Stats

This will be going on intermittently for a few weeks, so just skip the weather reports if you're bored (and you probably already are). My goal here is to see if my suspicion is correct, and Accuweather does indeed tend to offer impossibly rosy forecasts 10 to 15 days out, pushing them back with each passing day.

Accuweather's forecast highs as of today:
7/27 - 94° (eight degrees higher than yesterday's forecast--and notice that the cool temperatures are now forecast to arrive one day later than they were yesterdays))
7/28 - 81°
7/29 - 84° (four degrees higher than yesterday's forceast)
7/30 - 83° (three degrees higher than yesterday's forceast)
7/31 - 85° (five degrees higher than yesterday's forceast)
8/1 - 84° (four degrees higher than yesterday's forceast)
8/2 - 79° (three degrees higher than yesterday's forceast)
8/3 - 76° (golly gosh, there's that 76° forecast, 15 days out, just as it was yesterday!)