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.
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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
On the 2014 map I see no reason to slide the temperature scale to show lower temperatures that
do not exist and where temps above 85 can’t be distinguished. I can’t accept the reasoning.
This does appear to be intentional propaganda.
Better red than dead.
Farenheit. What a name eh? and Isambard Kingdom Brunell,Nicolaus Copernicus
They sure knew how to have proper names in those days.
What do we get ? Mike Mann
Get a decorator to do this (male or female). Not a scientist. They don’t know color hue and scale from squat!
Propaganda is probably the polite word for what they are doing with the color scale. I don’t think they are done yet. Soon freezing will be denoted in red (as the anomaly maps are sometimes shown at the poles)
I have been experimenting with warm vs cool colors since the late 60s.
Didn’t realize in the early 70s that I was being prophetic with this painting of “The Finnish Army” by using warm red for the snow…
(click on pic for larger version) (my Finnish friends think it looks too Russian to look like Finland):
http://www.purecolorartist.com/the-finnish-army.html
Unless I misread this, the author of this post misses an opportunity. I suggest taking the exact same data (either 2008 or 2014 or both) and apply BOTH of the color scales side by side. Taking a 2014 image with a “similar” distribution of temperature doesn’t have the same impact. Showing the change when applying the different scales to the SAME data would have been much more effective (albeit more work).
Thanks, Anthony.
I can see no expansion or compression in the new scale as NWS fits the same temperature range (80°F, but 10-90°F instead of 30-110°F) into the same color gradation. So there is a shift down.
And surely all those reds are visual proof of global warming. And in case of global cooling, they are ready. 😉
You left out the /sarc tag.
“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.”
If it were simply a case of the numeric scale adjusting to the high temperature entered, then the low ends on the 2008 and 2014 scales would match. But the high and low ends are equally shifted downwards by 20 degrees in 2014. That leads me to believe it really is a purposeful adjustment of the color scale.
http://www.straightdope.com/columns/read/845/on-the-fahrenheit-scale-why-is-32-freezing-and-212-boiling
The NWS Customer Service Survey does not accept my response (“You have not filled in the required fields ! Sorry !”) although all entries are complete. Perhaps my response would be accepted if I submitted a higher approval rating and deleted my suggestions for improvement?
The color scale, whatever the colors are, should be chosen so that it would be understandable if printed in grayscale.
Select Alaska – 60F is red! I wonder what happens in Winter?
http://preview.weather.gov/graphical/
Also, there is an option to select C or F (English or Metric). Click the menu button on the upper right.
I recommend a color scale based on how much money it costs to stay comfortable. If you can leave your windows open it’s green. The more you have to crank up the heat, the more blue. The more A/C you need the more red.
thingadonta says:
May 28, 2014 at 2:46 am
:…evenness is rare in nature, it may also be the case in the mind and in the eyes.”
It is called “exception reporting”. We are wired to see the differences, not the same. Which is why
“man bites dog” gets our attention while “dog bites man” does not. Also why you don’t feel that shirt you are wearing: you’ve tuned it out.
It is a very interesting point you bring up, though: if exception reporting is a drive across all of our emotional, intellectual, spiritual and physical lives, we will find problems, i.e. divergences from the “normal” whatever we do, wherever we look.
Another, primal, reason to be a skeptic: we are genetically predisposed for disagreement with what we experience as it appears to diverge from the central “norm”.
srvdisciple: hawaii would be perpetually green, but it sure costs a lot to live there even though there is little need for heat or AC.
I too prefer Fahrenheit for weather. It uses the full range of double digits. Celsius doesn’t, as temperatures never get above 65 C, and rarely above 50 C. In Fahrenheit, temperature are usually in the 0-100 range while temperatures above 100 are simply too d****d hot, and below 0 too d****d cold.
Celsius makes more sense for cooking. For science Kelvin is king.
@John M. Ware
Took Survey. Suggested utilizing Non sliding band for color scheme and [recoloring] prior images to match new proposed scheme
“To maintain Historic Perspective and for accurate historic comparative analysis, I would suggest maintaining a Non-Sliding band of color representation for temperatures and a recoloring of prior historic images to match the new style “
Also suggested utilizing the Green color as the Ideal Temperate growing zone temperature scale (75 to 85 deg F)
David Reese says:
May 28, 2014 at 7:13 am
“‘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.”
Managers at pay grades higher than the programmer instituted this change.
C’mon guys, they didn’t deliberately create a system that when given a mild year with virtually no extremes it would paint the whole country bright red. It was an accident.
If that one pixel was enough to slide the scale up then the same should hold true for today’s temperatures correct? If you look at http://graphical.weather.gov/ for the May 28th, 5 p.m. map you’ll see it max out at 100. Yet if you zoom in on Phoenix and Tucson you see temperatures well into the 100’s (104 and 103). Today’s map is an example of a redder (hotter) U.S. map because they threw out anything over 100.
EternalOptimist says:
May 28, 2014 at 7:34 am
Farenheit. What a name eh? and Isambard Kingdom Brunell,Nicolaus Copernicus
They sure knew how to have proper names in those days.
What do we get ? Mike Mann
Hence MANNipulated
For a computer program to adjust its scale to the range is absolutely standard. Not doing so would cause massive amounts of work everywhere that graphs are used. If a fixed scale was used for the weather map, then in a warming period the entire map would shift towards red, so the automatic scaling actually operates against the propagandists.