As I sit here looking at my weather widget, it shows that the current temp is 15F. However, the low for the day is 25F. It seems to me that the low should be 15F (or lower, if it was colder than that between midnight and now). I’ve noticed the same thing with the local news’ weather reports - it’s not unusual to hear something like “The low for today is 30, right now it’s 23.”
Does anyone know why the weather service(s) don’t update the highs and lows to match the real temperature ?
(if I wasn’t clear, I’m not asking why they aren’t accurate, but why they don’t change their “low” (or high) to match the temp outside). It seems like it would only take a line or two of code to change this, so I’m thinking there must be a reason for it.
I use weather.com; they show a high for the day and a “low” by which they mean the overnite low for tonite until tomorrow morning.
As an example, it was -5F here locally at 0500 but the high/low for “Today” is 23/19. When you ask for the details for “today” the 19 is the “overnite low.”
Maybe I’m not understanding what you’re saying (wouldn’t be the first time I mis-understood a simple explanation), but it’s 0930 local time here and the current temp is 19. The high/low for the day is shown as 40/25. Are you saying that today’s low is actually predicting the low between sunset tonight and sunrise tomorrow (or some other, possibly more specific, time)? Am I being too literal in thinking that “today” goes from midnight to midnight?
If they would spend less time with their Sinister Incantations and more time communicating, the Weather Guys would say, “It is 19 degrees right now in Metropolis, warming to a high this afternoon of 40. The low tonight will be 25.”
Well, that makes a little more sense, but what about tomorrow’s temps? I see that tomorrow’s high/low is listed as 45/35. That’s supposed to convey that the Friday high will be 45, but that the low that night (which is more Saturday morning than it is Friday night) is 35 ?
Should I have asked instead when the weather-people consider the day to start and end? And since it appears that they don’t start and end the day at midnight, why don’t they?
This is all seeming less and less like a science and more like a Black Art, as carnivorousplant said.
I think when people look at a weather forecast for the night, they want to know how cold it will get “tonight” (i.e., between the time they go to bed and the time they wake up). The “overnight” forecast tells them that.
Most people don’t care how cold it is between bedtime and midnight and also don’t care how cold it was earlier in the day just before sunrise.
Also, when a forecaster says, “tomorrow’s low will be ___” I don’t think most people are thinking about the fact that “tomorrow’s low” will tecnically occur at 6 am. Rather, they are thinking about “tomorrow’s overnight low” from bedtime tomorrow to the time they get up the following day.
In sum, it’s the difference between catering to people’s common practicalities notwithstanding technical accuracy.
Hey, I’m just sayin’ how weather.com does it, and you have it exactly right on what they do (use “low” to mean “the low which will happen between tonite and tomorrow morning after we reach the high for the day”).
It should really read today’s “high/tonite’s low” but then what if 0200 was the high…then the temp dropped steadily the next 24 hrs…
What you have to keep in mind is how weather is predicted. From what I understand, it’s based on very complex datamining and pattern recognition models based on atmospheric conditions over some period of time. That said, it is a prediction, IOW, the current conditions cannot be part of the prediction or it isn’t a prediction, it’s just a statement of the current conditions. In that sense, it makes sense to say that, essentially, the predicted high/low is 35/23 but the current condition is 19. The same could be said for when they say there’s a certain percentage of precipitation while it’s raining outside.
Of course, it doesn’t make sense to continue to discuss a prediction that is already false. It is equivalent to saying “I predict the world will end last Tuesday”. My guess is that the weatherman is just failing at filtering non-relevant information.
Of course, if the low really means Tonight’s low, it means he’s failing at explaining himself. I’d always thought the high/low refered to the calendar date for which the forecast was made, otherwise, it doesn’t make a whole lot of sense to me.
I disagree. In a controls system, for example, cruise control, you must take into account current conditions, speed and throttle position, to predict how the throttle needs to be adjusted. If you don’t take into account current conditions in a weather model, what can you take into account? You’ve got to have a starting point somewhere, and using current conditions are, by definition, your most recent data.
OK, I can buy that the weather forecasters feel that the day starts and ends at sunup, even if that seems entirely counter-intuitive to me (kind of like saying “We’re going to start each month at the full moon, regardless of what the calendar says”).
What about now, when the current temp is 42 and the high is 41? I could appreciate the honesty of someone admitting they were off in their prediction, but I’ve seen the predicted high change, sometimes several times, during the day (so I know that they’re not opposed to changing the high/low temps during the day). I’d think that a good time to change it would be times like this.
