They seem to be different for every station and newspaper, and all are revised day by day.
If this is Monday, Friday will have 5 different published/aired descriptions by the same forcaster before it’s over.
So, who are they fooling? They can’t predict tomorrow morning at midnight, much less 5 days.
I can give you a better guess right now for Friday:
Minnesota- like yesterday only 10º hotter and wetter snow on the Canadian border.
New York- like yesterday but 10º hotter and more humid.
Florida- lives up to it’s name as the Sunshine State, but also has torrential rains from noon to 1pm, like most other days.
Like the other forecasters, my estimates are ±20º, and come with profuse apologies about how that last front took us all by surprise.
As a meteorologist, although I don’t do forecasts yet, I can explain why.
The numerical models used in weather prediction are often inaccurate. However, it is rare nowadays to totally bomb a 24hr or less forecast. As computing power increases, the models will continue to get better. That being said, there is some skill in numerical models out to 7 days (meaning, better than a total crap shoot). Yes, they are often wrong at that time period, when compared from a certain day.
The point of 5-7 day medium range forecasting is to determine the trend. If the forecast calls for showers and thunderstorms and highs in the low 80s for the weekend, on Tuesday, there is a chance that will verify. One doesn’t use the medium range forecasts to make exact forecasts, but as a general idea on what will happen.
Yes, there are inconsistencies between different sources, because meteorology is still an inexact science. Different models (I can think of 5 off the top of my head, and these are just medium range models) have different methods of prediction, and all may come up with different solutions. This is due to model physics, but also to the relative lack of data.
Yeah, I’m rambling now. In summation, don’t use the medium range forecasts for exact solutions. Use them daily, and as you get closer to the date, the forecast generally converges on a specific answer.
But, aren’t you like economists, always right in retrospect, but never in 5 day predictions?
I think you just proved my point. You said the 5 day forcast gets calculated 5 ways, then “refined” until it’s one day away, when you can nail it 75% of the time. Well, so can my bunions, and they didn’t have to go to school to figure it out.
Am I missing something?
What are days 3-5 doing in the paper if they are so far off? Don’t you realize the gullible decide whether or not to rent a tent for the outdoor reception based on the 5 day forcast?
In a way, you may think that forecasters run the models, which chugs out a point forecast, and then is sent to the newspaper. Actual people (go figure) do refine forecasts, because frankly, if you saw the raw model output sometimes, you would gag.
Yes, the 3-5 day predictions are usually off to some degree, but I would venture to guess that most of the time (east of the Rockies) the 3-day forecast is a good estimate of what will happen (and does verify).
I will try to find some statistics based on forecast accuracy out to 7 days, and will try to link here.
As to those gullible people, well, if they think that a forecast on Monday for the following Saturday won’t change as time goes on, then they must have moved from Southern California.
An image showing average temperature differences between the 3 and 7 day period here. I am not sure how this graph was calculated, but I’m assuming it can be used as a general explanation, as opposed to a specific point. Notice that errors overall are smaller during the summer months, which is to be expected.
Basically, all this shows there is some skill involved. Personally, I take everything beyond 4 days or so with a grain of salt, and anything less than 3 days or so to be a fairly good judgement on what will happen. With the infinite amount of variables inherent in any weather system (not to mention small-scale features below the model resolution), I think that forecasts are pretty good, all things considering.
When I was a kid I did a test (in Atlanta, GA, don’t know if it would work elsewhere).
My forecast (tomorrow will be the same as today) vs. Guy Sharp on WSB TV. Despite his name, I beat him cold. (He later ran for Governor. I was worried.)
I think that the OP’s issue is this: go ahead anddiscuss the trends in the overview (it’s not like it doesn’t get a disproportionate share of news time anyway) but spare me the ‘5 day’. It’s ridiculous to dignify it with the term “forecast”. Putting it on the screen next to tomorrow’s forecast is misleading at best.
My guess is that it will prove to be a better predictor of what the weather won’t be. But I’ll conduct a test to find out. I’ll get back to you.
Another peeve: how often have you heard the weatherman say “well, we dodged the bullet today” and look out the window and see rain (or vice versa) I live less than a mile from the nearest National Weather Service center. I understand why this might happen, but it underscores the silliness of telling us what the weather outside is right now; why bluff if you’re so easily caught? (but we forgive 'em anyway)
I totally agree with you. I think I have misunderstood the OP to some degree, assuming he was venting more toward the actual forecast, as opposed to the METHOD of transmission.
The official NWS point forecasts are very vague in the 3-5 day period. I’m thinking that if the media did this though, it might look badly on them, for some reason, even though everyone knows that meteorology is an inexact science.
The firestorm raging today in Los Alamos NM right now is a tragic example of the Long Reange Forcasting myth that meteorologists propagate.
For those not following the story, the tragedy was started by a “controlled burn” that was permited because of an erroneous 2 day weather forcast. The hot dry high winds that whipped up the fire had only been predicted some 8 hours before they arrived.
The 5 day forecast is like today’s horoscope: only the author knows how unpredictive it is, yet many in the community base their decisions on it.
