Do not understand temperature change in chart

Hi I’m checking out the new features with the one-hour step of the GFS and icon I cannot understand want the temperature variation mean on the chart see screenshot.

When the cold front approaches I can see temperature changes in the future days. But the Chart shows big temperature changes (blue and red areas ) but is not consistent with the regular temperature line.

Can you explain what’s the interpretation of this colors


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@neavilag Red is a warm front blue is a cold front

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Hi Bryan, thanks, I understand that, is just that does not make sense, if you see the temp line, for prior 24 is not the value of the red / blue areas, in other words

No cold of warm front on the forecast, did you check the image ?


@neavilag yes seen the image there are always warm or cold fronts they don’t tell temperature they just indicate warming and cooling trends

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@neavilag when you slide left to right watch the temp in comparison to the warm/cold front just shows a little or big change in temperature

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This certainly looks like a bug. I’ll check it out for the next release.

Cheers, Duane.


This is how mine looks, pretty normal for this time of year showing unstablility or instability lol :joy::joy:


In your screenshot @BrianLY-38 the bug is eaven more clear.

If looking in the big blue area, and the red area to the right, is seams as if the temperature that the graph is compared with is 3 days prior rather than just the day before.

This is less clear in the example by @neavilag.

The difference between the example by @neavilag

and by @BrianLY-38 is that in the example by @neavilag the data in the graph is from two different sources, and is seams as if the temperature in red/blie is being compared to a completely different graph, perhaps from a different source.

@Ohan @neavilag

It’s not showing temperature just means warmer or colder air mass

From the Flowx help:

“Cricket Chirps - this is the which shows the temperature (blue line) along with cold (blue) and warm (red) changes compared to the same time on the previous day.”

So what is being discussed here is a bug that leads to the DeltaTemp graph not being compared to the same time on the previous day, but instead to something else.

In some examples it seams to be to the the same day 3 days earlier, and in other examples to something completely different.

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It’s not comparing warm and cold temperatures it’s showing warm and cold fronts

thank you for your feedback but I still consider it’s a bug

I agree not necessarily a cold front but expecting to show temperature change in the last 24 hours

I am passing the bug in red as it’s currently and a screenshot from last year when I think is okay.

Painted area matches the prev 24-hour temperature chart


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I thank you for your feedback

I cannot identify which data is the bug showing

I don’t think that Delta temperature shown has occurred here in the last 3 months. As we don’t have those big temperature variations year-round.

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@neavilag when you have temp selected along with warm and cold fronts when it’s a small warm or cold front the temperature line covers them that’s why I don’t have temp selected.

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If you add the temperature to the same graph as the the warm, and the cold blue/red areas, then it’s easier to see that they are temperatures.

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@Ohan it just means there is a warm or cold front moving through Temps rise (warm front) Temps drop (cold front)

Me neither. Let’s see what @duane can make of this.

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Hi all,

Delta temperature shows the change in temperature from the same time the day before. This is good at highlighting changes in temperature, i.e., getting colder or warmer, which is often caused by warm and cold fronts. I’m guessing there are other weather phenomena that will cause changes in temperatures.

There is definitely a bug.

Before, GFS had a constant 3 hour time step so I would subtract the temperature form 8 time steps (8 x 3hr = 24 hours) prior to get the change in temperature.

Now, GFS has both 1 hour time steps and 3 hour times steps after 5 days of data but I assume 1 hour time steps all the way through when calculating the delta temperature. This is why you see the bug after 5 days.

I will fix this today.