# 1985: Meteorologist

 Meteorologist Title text: Hi, I'm your new meteorologist and a former software developer. Hey, when we say 12pm, does that mean the hour from 12pm to 1pm, or the hour centered on 12pm? Or is it a snapshot at 12:00 exactly? Because our 24-hour forecast has midnight at both ends, and I'm worried we have an off-by-one error.

## Explanation

 This explanation may be incomplete or incorrect: Created by an OVERLY ANALYTICAL METEOROLOGIST. More on Cueball's 2nd panel. More on Blondie's linguistics, explanation for dummy pronoun. Wiki links. Do NOT delete this tag too soon.If you can address this issue, please edit the page! Thanks.

Although we’re constantly exposed to them, many (most?) people don’t understand the details of how to properly interpret weather forecasts. This comic takes this to the ridiculous extreme of the weather reporters themselves not understanding, and asking questions about it while on-air. It shows questions asked by three different people with different backgrounds: mathematics, linguistics, and (in the title text) software development. In addition, many terms and numbers used by weather forecasters have very technical definitions and usages; however, because they are used so commonly (whenever someone tells us the weather), it is easy to assume we understand what it means. This comic also points at this fact by asking clarifying questions about subjects that meteorologists know but the average person doesn't (such as the definition of "scattered showers" and how it's determined, what a "chance of rain" means, and so on).

The first meteorologist, Cueball, has a background in pure math. His forecast states that each of the next five hours has a 20% chance of rain. It could be that rain was certain, but it would only last about an hour and will come within the next five hours. That would give 20% for rain in each hour but certainty of rain within those hours. This corresponds to his last question in the first panel.

But before that he focuses on probability when he asks if each hour is independent or correlated. If each hour were independent, there would have been a 67.232% chance to rain at least once. However, if the hours had been correlated, the chance would be less, since if it didn't rain in the first hour, it would decrease the chance of rain in the next hours. However, it would make it more likely of raining in all 5 hours, as it would be a .032% chance if it wasn't correlated. But if it was correlated, rain in the first hour would make it more likely to rain in the subsequent hours.

In the second panel he continues to discuss what scattered showers means. Like most of the other weather terms in this comic, the term "scattered showers" is one whose technical definition is largely unknown but appears simple enough that most people would assume they understand what it means. "Scattered" refers to when the rain covers roughly 30% to 50% of the area. To somebody who doesn't know this, like the first meteorologist, there's still the very valid question of how likely it is to rain in a specific spot, and how this is affected by the previous chance of rain. Not to mention, the percentage that defines "scattered showers" implicitly assumes a surface area that is accounted into the percent. Cueball rightly asks clarification on how large the location used to determine "scattered showers" is.

Finally in that panel Cueball begins to explain that he has asked the management about these things, but that they have stopped replying to his e-mails. At this point he spots the security guy coming over, and the screen goes black in to a technical difficulty screen that excuses this behavior to the viewers.

Questioning these things on air is likely confusing to the watchers, although they are all valid questions. But this may lose viewers and the news network is afraid of this. The technical difficulty panel further cements this, apologizing for hiring a person with a pure math background. Often seen as one that do not understand how to talk to regular people.

When they get back on air gain a new meteorologist, Blondie, steps in. The management enquires (on air) to make sure she is not also a mathematician. She states no, but tells that she has a linguistics degree, which the management thinks is fine, and thus believes they have prevented the problem with Cueball. However, this proves to be in vain, as Blondie goes into a tangent once more but from a linguistics standpoint, rather than a mathematical one, detailing the true meaning of the word "it" as referring to the weather. After one panel of this the management calls for security again.

While, at the most basic level, human speech is broken into subject, object, and verb; for some reason we are capable of producing and comprehending speech without both objects or verbs, but there is a certain "resistance" to speech without a subject. Thus if you are in the passenger seat of a car going down the highway and happened to see some deer in the trees nearby, you could simply say "Deer.", rather than "there is a deer over there", deer being the subject of the sentence. However, if you noticed that it had begun to rain, you could not simply say "Raining." on it's own. Feel how that sentence just seems weird? Hence we have developed the tendency to use the filler word "it" despite the fact that when we say "It's raining." the "it" is not a reference to the clouds producing the rain, but the general state of the rainfall around us. (McWhorter, John. Understanding Linguistics: The Science of Language. https://www.thegreatcourses.com/courses/understanding-linguistics-the-science-of-language.html )

In the title text, the news station has made the same error again, by this time hiring a software developer as the third meteorologist. This last person is stating concerns about the feasibility of the time system used to correlate to the weather patterns. Because it appears simple, many people would simply assume they understand what is being said when a meteorologist talks about "12pm" or "1pm". However, because software developers frequently have to deal with things such as specifying exactly what time-label means what, the new meteorologist begins to wonder what time period is actually meant on a per-hour forecast. On such an hour forecast does 12pm refer to the hour from 12 to 1pm, from 11:30 to 12:30 or is it actually only to the weather precisely at 12:00 that is referred to? The software developer also worries about an off-by-one error, which is a common error in software development occurring when boundary conditions include one element too few or too many: when counting by 24 once every set period (for example), it is common to forget whether the count should stop at 23 or at 24, especially if the number 0 (midnight) is included. In the 24-hour forecast, that means there's 25 hours represented every day, and the software developer worries that these 25 hours might add up and, every progressive day, the forecast is one more hour off.

Of course it should be pointed out that hiring someone without any meteorological training to read the weather does not make them an actual meteorologist, no more than say hiring a bricklayer as a doctor would actually make them a real doctor.

Management would certainly answer the mathematician's questions! The questions themselves have been asked of meteorologists before, and NOAA has published relevant answers for probability of precipitation, as well as timing and the meanings of particular forecast words. The naming is also addressed here.

Regarding probability of precipitation, NOAA forecasts give the probability that it will rain at all at any given point in an area. To rephrase it, it is the probability of rain occurring at all within a forecast area, multiplied by the percentage of area affected by the rain. The "forecast area" is a clearly defined area of land and can be seen in the map of any official National Weather Service forecast. Here is an example.

Regarding the timing of the forecast, an hourly forecast gives the probability for each particular hour, stretching from the time listed to right before the next hour listed. So, the forecast for noon describes the time period from noon to 1pm. The forecasts for individual hours can be correlated; for this reason, the NOAA generates forecasts that stretch over longer time periods, giving a useful estimate for that time range. Thus, the chance of rain for "Today" specifically means: what is the chance of it raining at any given location during any time between 6am and 6pm?

Regarding phrases like "scattered showers", this specifically means a 25-54% probability of precipitation from convective cloud sources. Other phrases, and when they are used, are detailed in the chart at the end of this PDF.

So, to conclude:

• "How likely is it to rain this afternoon?" We don't know, you need to show the 12pm to 6pm forecast, not the hourly.
• "Is each hour independent? Correlated?" Hourly values are given for that hour only. They can be correlated, hence why they can't be used to calculate the answer to "How likely is it to rain this afternoon?"
• "Is rain guaranteed and we're just unsure of the timing?" You cannot tell from the data given. It's possible (though unlikely), that this is the case.
• "It says 'scattered showers.' Is this the chance of rain somewhere in your area?" Yes, it is, and it means the the rain will come from convective cloud sources with a probability of precipitation somewhere between 25 and 54%.
• "How big is your area?" It's detailed in the forecast the mathematician would be reading from.
• "What if you have two locations you're worried about?" You would check two separate forecasts, one for each area.
• "Hey, when we say 12pm, does that mean the hour from 12pm to 1pm, or the hour centered on 12pm? Or is it a snapshot at 12:00 exactly?" It means the hour from noon to 12:59pm.

## Transcript

[Cueball is presenting a weather forecast while seated with his arms resting on a table. The graphic to the left of Cueball shows five hours from 12pm to 4pm, each with a rainy cloud icon and the figure 20%. The "News 4 Weather" logo is shown on the bottom left.]
Cueball: Our forecast says there's a 20% chance of rain for each of the next five hours.
Cueball: How likely is it to rain this afternoon? It's a simple question, but I don't know the answer. Is each hour independent? Correlated? Or is rain guaranteed and we're just unsure of the timing?
Cueball: It says "scattered showers." Is this the chance of rain somewhere in your area? How big is your area? What if you have two locations you're worried about?
Cueball: I've asked management, but they've stopped answering my emails, so—hang on, the security guy is coming over.
[A black screen is shown with white text:]
Technical Difficulties
We apologize for hiring a meteorologist with a pure math background.
We'll be back on the air shortly.
News 4
[Cueball is replaced with Blondie.]
Off-panel voice: And you're not a mathematician, right?
Blondie: No. I do have a linguistics degree.
Off-panel voice: That's fine.
Blondie: It might rain this afternoon.
Blondie: But what is "it" here? Is it a true dummy pronoun, as in the phrase "It's too bad?" Or is the weather an entity?
Blondie: Also, what if I say, "It's hot out, and getting bigger?"
Off-panel voice: Security!

# Discussion

I’ve wondered about this (from both the math and software development perspectives anyway, not the linguist), so I look forward to seeing some actual answers as the explanation gets filled in :) PotatoGod (talk) 16:36, 25 April 2018 (UTC)

The weather service has a nice explanation of this. After reading it you come away understanding that the percentage chance is... still almost impossible to discern :) 172.68.189.205 (talk) (please sign your comments with ~~~~)

I really liked this one. I don't know why though. Linker (talk) 17:35, 25 April 2018 (UTC)

Yep - all three of the 'experts' express problems that I have with every single weather forecast. It gets worse though. Our local TV station uses a rotating 3D graphic of downtown Austin where the shadows of the buildings flicker violently as it rotates - they've been doing this for YEARS. I'm a 3D computer graphics professional and I know PRECISELY why that is happening (they are rendering the back-faces of the building polygons in the shadow rendering pass instead of the front-faces...trust me on this one!)...I could fix the bug with ONE LINE OF CODE - and I bet I could find and fix it within 20 minutes if left alone with the source code. But when I call them and BEG to be allowed t...SECURITY!!! SteveBaker (talk) 17:36, 25 April 2018 (UTC)
Hah, that's pretty funny, but understandably frustrating. I rarely watch the weather though... that is why I find it a little strange I liked it so much. Have you actually called them though? I mean, if you have proof to show you are a professional...Linker (talk) 12:33, 26 April 2018 (UTC)
Randall
wonders about something and puts it in an xkcd comic.
Explainxkcd participants

TobyBartels (talk) 20:52, 25 April 2018 (UTC)

Am I allowed to be slightly offended by the suggestion that "information being conveyed is to people, who would probably be able to interpret it easily"? Okay, I'm a software engineer, but even if I weren't I'd still not know whether the report system defines "12:00" as "in the period between 12:00 and 13:00" or "between 11:30 and 12:30". I usually wonder, but get so many variants of weather reports exposed to me that I can't be bothered to check which arbitrary decision any given one has made, and whether they all agree. A software engineer might instantly spot the ambiguity, but it affects everyone. Fluppeteer (talk) 23:58, 25 April 2018 (UTC)

Clearly, what that sentence is trying to convey is that software developers are no longer considered "people" - since, you know, everyone knows that software developers have actually been replaced by robots. ;p
I agree that that section is pretty poorly worded (in more ways than one) and was likely written by somebody quickly trying to get as much explanation out as possible so that future people could fix it. So, I'm going to see if I can fix that sentence and the surrounding section. Jeudi Violist (talk) 01:40, 26 April 2018 (UTC)

As someone who's asked many questions along these lines, this comic makes me happy. Elvenivle (talk) 01:53, 26 April 2018 (UTC)

There is no such thing as "12 [post meridiem]" - it's literally at meridian. Grammatically, "pm" should be capitalized as an abbreviation. Should this be noted? (The linguist could explain it to the programmer.)Roguetech (talk) 12:54, 26 April 2018 (UTC)

The text is currently mathematically incorrect about correlated events. The type of correlated described is just a special form. 172.68.51.22 (talk) (please sign your comments with ~~~~)

Captcha1 is no longer working, so you can no longer create new accounts here or edit anonymously. 172.68.51.22 (talk) (please sign your comments with ~~~~)

See above the explanation. At the time of writing this (and the above comment) this text was there:
```Hi all, the upgrade is now going to happen next weekend, the weekend of the 28th/29th. Bear with us as we get up to date and fix the ReCaptcha.
```
So just wait a few more days.--Kynde (talk) 21:59, 26 April 2018 (UTC)
Captcha1 works fine, you just have to do what it says (that’s how I’m adding this comment now) 162.158.62.153 04:30, 27 April 2018 (UTC)
New category for weather/meteorology ?

Do we need a new category for meteorology or wheather/wheather forcast, maybe one combining all things to do with weather and possibly climate? Suggestions for a name for such a category (or if we need it or more than one) would be appreciated. I have found the following comics apart from this one, that has some clear relation to weather in some form or another:

Plus of course the whole set from

and possibly also from

Feel free to add your ideas. --Kynde (talk) 21:51, 26 April 2018 (UTC)

I think we can create a new "Weather" or "Meteorology" category, and make the hurricane and tornado categories subcategories of the new weather/meteorology category. But should it be weather or meteorology? Herobrine (talk) 05:38, 27 April 2018 (UTC)
How about "Weather and Meteorology"? Elektrizikekswerk (talk) 10:02, 27 April 2018 (UTC)

Does anyone know what the part in the explanation about classifying linear functions into two vector spaces means? Neither I nor anyone I know who's studied maths knows how to interpret this.

Re 'even if I weren't I'd still not know whether the report system defines "12:00" as ...': Well, isn't part of the joke that it doesn't really matter? Weather forecasts use all these precise numbers and they have specific definitions for everything, but it's all just approximations -- there are wide error bars that are not mentioned. When they predict the temperature as "68 degrees", I mentally translate that to "high 60's". And "1pm" means "early afternoon". So even though their prediction for 12:00 means from 12:00 to 1:00, it's also likely to be a good approximation for 11:30 to 12:30. . Barmar (talk) 16:29, 27 April 2018 (UTC)

1) '... there is a certain "resistance" to speech without a subject. Thus if you are in the passenger seat of a car going down the highway and happened to see some deer in the trees nearby, you could simply say "Deer.", rather than "there is a deer over there", deer being the subject of the sentence.' Sure, you can! How do you know that the person said "Deer" and not "Dear"? 2) If you are one of those who prefer punctuation inside quotes, note that "Dear?" is not the samething as "Dear." as the pitch could be used to disambiguate "Deer." and "Dear?"; this is not the case for "Deer." and "Dear." 3) "Of course it should be pointed out that hiring someone without any meteorological training to read the weather does not make them an actual meteorologist, no more than say hiring a bricklayer as a doctor would actually make them a real doctor." So what is "a real doctor"? I consider that a real doctor is someone who has a doctorate (degree). Some consider it to be someone who is a medical doctor (and who probably does not have a doctorate). 4) My degree is a minor in Math, a major in Computing Science, and one course in it was in Linguistics. Gene Wirchenko [email protected] 108.162.216.220 05:45, 1 May 2018 (UTC)

The chance is 20%+20%*0.8+20%*0.64+20%*0.512+20%0.4096=20%+16%+12.8%+10.24%+8.192%=67.232%. 162.158.91.137 15:00, 29 July 2018 (UTC)