Back in June 2008, I did a post titled Color and Temperature: Perception is everything.
One WUWT reader, Jes Simon noticed that since that time, something changed in the way NOAA was presenting the CONUS surface temperature, he worked up this comparison at right, and magnified below. I located the full size graphics as well, and he is correct, there has been a change, but the reason isn’t what he concluded.
Here is the original image from 2008, seen at left in the above image.
And here is an image I got from NOAA’s forecast database on 5/27/2014 that has a similar distribution of temperature:
Now some might say that something insidious is going on here, that NOAA has purposely adjusted the color scale, they’d be half right.
What we have here is a sliding scale where the units change range, but the color range stays the same. Compare the two scales side-by-side:
The reason for this is some small pockets of 110F+ temperatures in the 2008 map, in and near Death Valley, seen magnified below, and with the scale and arrow placed so that it is obvious.
So the point here is that just one station, plotting a single pixel of 110F+ temperature is enough to change the entire sliding scale. NOAA isn’t really doing a purposeful adjustment of color here to alter anyone’s perception, it is just the program adjusting the numeric scale based on the range of temperatures within the CONUS.
A better way to handle this problem is to create a set of fixed colors for temperature, much like Dr. Ryan Maue did for WeatherBell’s CONUS temperature images:
![rtma_tmp2m_conus[1]](http://wattsupwiththat.files.wordpress.com/2014/05/rtma_tmp2m_conus1.png?quality=75)
Now, NOAA is about to redo the presentation with a new look, like this:
Source: http://preview.weather.gov/graphical/
Note that they say:
Below is a proposed replacement of the National Weather Service Graphical Forecast Page, a product of the National Digital Forecast Database. Comments are encouraged and can be done by taking our survey.
The survey can be taken here http://www.nws.noaa.gov/survey/nws-survey.php?code=wxmap
Comments can be left. This might be a good time to suggest a color scale that doesn’t give hot yellows and reds for 70-80F temperatures.
UPDATE: 5/29/14 Reader Rick W. sends along this image and notes:
![qrTVPLL[1]](https://wattsupwiththat.files.wordpress.com/2014/05/qrtvpll1.png?quality=75)
So is one pixel enough to slide NOAA’s magical scale as Anthony claims? Apparently not. Here is the NOAA high temperature map for May 29th at 8 p.m. EDT. Note the temperature scale goes from 0 to 100 degrees.
The coldest point on this map is the Mount Rainer area in Washington State. It is showing a deep blue pixel indicating a temperature in the low 30s.
The hottest area on this map is the southwest. It is showing temperatures between Phoenix, Yuma and Indio above 100 degrees. This is not a pixel we’re talking about; it is several thousand square miles of temperatures above 100 degrees.
Note the temperature scale does not go above 100 degrees in any of these maps.
================================================================
So rather than speculate as to how the NOAA system works, I’m going to ask NOAA directly rather than speculate further. When I get an answer on why the map scale/colors are not representative of actual surface temperatures at the high end, I’ll post either an update here or a new post about it. – Anthony
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But hot yellows and reds are all the style, doncha know. Actually, it is amazing how warm it makes the map look, and I’m sure they are happy with that. It’ll be something if they pay attention to the suggestions.
I just wish the US could drop the F scale and use C like everyone else. That would really twit the tails of the Alarmists, i.e. having the local TV weatherman warn of a 40 degree forecast.
The other favorite trick is to not have a neutral tone around zero for anomaly maps. In reality, a (IMHO fairly large) band of anomaly near zero is effectively the same as “no change”. But all the big player’s maps have a bright line at zero, with any positive anomaly shown as the first red shade, and any negative anomaly shown as either a green shade or the first blue shade.
Back on topic, a fixed color scale for absolute temperature maps makes sense too much sense and is too honest, so I’m cynical enough to believe that it won’t be done unless the color mapping is biased so that the “normal” temps make the map look hot.
‘This might be a good time to suggest a color scale that doesn’t give hot yellows and reds for 70-80F temperatures.’
which will see adoption straight after the Turkeys vote for Christmas .
It’s no accident that red/bright orange is used , and it is not about the science it is very much about how their colours are perceived by humans.
Colour all the scale green.
For the eye sees better in green
Shades of all be seen
Please, please do not change the Fahrenheit readings to Celsius (centigrade)! The C scale is rougher, with a larger range per degree, thus not as accurate without more decimal places. Not only that, but the F scale has a better rendering of freezing fresh water at rest (32 degrees) and the point where all water is frozen (0 degrees) regardless of motion (I hope my understanding of that range is accurate). F is Fine! C is Curmudgeonly! Keep F!
‘This might be a good time to suggest a color scale that doesn’t give hot yellows and reds for 70-80F temperatures.’
Not to mention showing an ominous deep red for normal human body temperature.
Are we all roasting from the inside out ?
For colour blind humane see.
different colours be difficult to see compre’.
Take viridian green as main centre theme.
And it is even worse when reds are used to show higher than average temperature anomolies like the pink Antarctic or red siberia.
I came across this curious little bit of info years ago, apparently our eyes have 3 colour filters provided by evolution (dogs only have 2), which do not give evenly spaced filtering; they filter colours based on their arbitrary chemical structure, which gives a distinct bias away from yellow, in particular. So what you see in the world is a ‘false’ representation of reality, we don’t see enough yellows, and we see too much red and blue.
This may sound trivial, but it has implications, it means that most of art is a superficial construction, it is dependent on the arbitrary filtering in our eyes. (The Mona Lisa would be seen by an alien differently). And the relationship between science and art is also affected, which is partly why science and art are sometimes at odds etc etc.
As for maps, the inability of the eye to pick up yellow might also affect them, which is perhaps why yellow is often given a very small range in colour schemes?. This has implications for the maps above. Because yellow is often in the middle of colour schemes, it may also mean that maps tend to one extreme or the other too easily, they tend to polarise cold and hot, which may not be polarised.
And the mind? Perhaps something like this is why people tend to become polarised, the’ middle ground’ is easily excluded by the way the mind has evolved. You see the problem, evenness is rare in nature, it may also be the case in the mind and in the eyes.
When a lot of colours are used, as in the Weatherbell map, I for one find it difficult to distinguish between some of the colours, especially if they are for a small area. I end up having to look at the regions next to them to work out what part of the scale they are meant to represent. I’ve noticed the issue you mention on some of the ice page maps. All of a sudden, it can look like a large area has warmed when it’s just that the scale has shifted.
“This might be a good time to suggest a color scale that doesn’t give hot yellows and reds for 70-80F temperatures.”
Good idea and worth commenting, but not a hope.
My “climate” prediction is another 10 or 20 degree shift if the scale making it redder.
Temps have not been moving 17 years but the marching orders are clear. By whatever means necessary, including outright untruthful statements as seen from Kerry recently and in NCA, the “climate change” is to be presented as “happening now” and ” in a place near you and your family”.
This is being pushed at national and state level by all arms of government.
This is the year of the big push. UNFCCCP wants all countries to sign a legally binding endebtment of future generations to the tune of $100 BILLION per year EVERY YEAR.
And this is the bottom line issue. As it always was in politics FOLLOW THE MONEY.
don’t expect more logical cooler colours any time soon.
I would ask “Does the software work the same way with the low/minimum temperatures?” before returning the verdict.
Quite frankly,as one of the 5 to 8% of males who are color blind, I have no use for charts that use colors to convey information and fail to provide numerical values accompanying the colors.
In the case here, I since all the colors are doing is to indicate intensity , i.e. how much/little heat
(temperature) there is at various places, the proper method for all concerned would be to use grayscale, where darker means hotter. In this case colors actually confuse the issue rather than clarifies it, as has been noted. In general I recommend NOT using colors to convey information.
Amazing that 99% of color blind folks are red-green insensitive, and yet what did those who created stop lights use for colors? Yep, red and green, the dumbest choice available.
@John Ware. Water freezes at 32F. The Fahrenheit scale is a centigrade scale. O F was the coldest repeatable temperature Fahrenheit could create. 100F was the temperature of the human body, as he measured it. and 200F was the boiling point of water. The fact that ALL the rest of the world uses Celsius already, and even American science is done in SI units means the days of Fahrenheit are numbered. I don’t think that there’s much of a problem with there being 2 F in every C. If it matters, people can handle a 1/2.
Done..It will be interesting to see if public servants will actually declare the results if everyone wanted it changed or even the majority. But that would only happen in a democracy, wouldn’t it !!..:)
Use the drop-down box to change from the National to the Hawaii map. Check out the ocean color. It’s a hideous yellow-orange and they make it more yellow when you switch from maximum temperature to minimum.
To my eye the Weatherbell map shows weather. You can clearly see the front pushing down into Texas and the midwest. Which tells you what to expect over the next day or two.
The US Weather Service map on the other hand doesn’t show weather. So much of the map ends up being the same color that everything is washed out. You can’t see where the fronts are developing, so you can’t get any idea of what is likely going to happen.
There is really nothing unexpected in this. Government agencies are largely ineffective, because they do not have to compete. No matter how poor their products, they cannot go out of business.
Yes Farenheit is much more precise. As far as I know from personal experience most meteorologist prefer to work with Farenheit. Chick farms as well LOL (they have too)
John M Ware
“Not only that, but the F scale has a better rendering of freezing fresh water at rest (32 degrees) and the point where all water is frozen (0 degrees) regardless of motion (I hope my understanding of that range is accurate).”
It isn’t, there is no such thing as a “point where all water is frozen regardless of motion”, it all depends on how much the water moves. Zero on the Fahrenheit scale is quite arbitrary (it was simply the lowest temperature that could be achieved in the laboratory in the early 18th century, by mixing ice and and a saline solution), in contrast to the Celsius scale where 0 and 100 mark the points where water freezes and boils respectively at normal air pressure.
As a matter of fact, I find the fact that the F scale has the freezing point at such an arbitrary number as 32 quite annoying since it makes quite difficult to locate on e. g. a map with isopleths.
Didn’t a study out of Sweden say that people started to drop dead from heatstroke as soon as temperatures start to get into the 70’s??? /sarc
Red is the new green….
Why would you want to use a temperature scale based on French socialism? I mean, if you’re not going to use a 10-day work-week (don’t worry, you still get Primidi & Décadi to drink yourself into oblivion) how dedicated are you to this concept?
Anyway, everybody knows that the only real temperature scale is Planck.
“NOAA isn’t really doing a purposeful adjustment of color here to alter anyone’s perception, it is just the program adjusting the numeric scale based on the range of temperatures within the CONUS”…This might be believable if computer programs were to write themselves. I can’t imagine the programmer not noticing the effect.
John M. Ware says: May 28, 2014 at 2:13 am
Please, please do not change the Fahrenheit readings to Celsius (centigrade)! F is Fine! C is Curmudgeonly! Keep F!
_____________________________
Yes, but there are only a couple of Dark Age nations in the world who understand what on earth the F system is all about. Freezing at 34 degrees and boiling at 275 degrees? What is that all about?
Ralph