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Region of Lower CX! Clouds


Bulau
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I had read of Hodge's low cloud problem here:

http://www.forum.aerosoft.com/index.php?showtopic=24556

I just made a short task out of Heath Canyon. I am careful when setting weather to only set a single layer of cu at the height I want, so this task weather has a single cu layer 2200-3200m. I'm using CumulusX! with the default configuration, which has thermals from 1500-3000m, but I'm assuming it will use the levels set in the FSX weather.

And it did, for the most part. At Heath Canyon and around it, both the FSX and the CumulusX! clouds are all at 2200m, where I want them, but to the south towards the TP at Terminal, I can see some CumulusX! clouds that are lower. So, I head there, and sure enough, there is a broad region around the turnpoint where all the CumulusX! clouds are down around 1400m. The FSX clouds are all up at 2200m. Looking south and west, clouds are all up where they should be at 2200m.

What could cause this cloud level anomaly? It doesn't seem to be the same reason in Hodge's thread.

125kmNoobHeathCanyon.zip

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post-36204-077714500 1294362435_thumb.jp

post-36204-019773000 1294362452_thumb.jp

post-36204-051780200 1294362474_thumb.jp

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Hi Dave,

it can be that CumulusX! did not recognize the FSX clouds around the turnpoint. The cloud coverage which is reported by the FSX METAR system is often different from what you see. I such a case, CumulusX! falls back on the global weather setting of FSX, and if there is a suitable cloud layer defined there it uses this ceiling. If there is not even a suitable global cloud setting, it makes a blue (unless Unblue is selected) thermal with a random ceiling. This happens frequently with the "Fair weather theme" and also with real weather.

best regards,

Peter

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I haven't really explored much of the weather options in FSX. For setting these tasks, I'm trying to avoid the unexpected, so I've been following the advice I have usually found associated with CumulusX!, which is to first select "Clear skies (clears all weather)" for the weather theme, then select User-defined weather...Customize...and set the single cloud layer where I want them to be. So far it has always resulted in what I expect...except for this one occasion, which seems not repeatable.

Are there occasions where the above procedure can still result in this sort of unexpected weather results? Would it help to edit the CumulusX! configuration so that the thermal height range matches what I'm setting in FSX for cloud level?

Now, don't get me wrong...I like soaring weather to have a little variation from run to run. In Condor, I always check the "Randomize" box, so that even though the weather is set a certain way, if I fly the same task twice, I don't see the same thermals in the same locations. I realize CumulusX! does not have such a checkbox, and that's fine. But this anomaly was a little too....anomalous, if you know what I mean.

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  • 1 month later...

I have just recently had this Phenomena whilst soaring in Omarama.

I was using a shared CumulusX! script for multiplayer use so my FSX cloud height was fixed at 8000ft, winds at 240/9knts and my CumulusX! was also fixed at 8000ft.

The majority of the thermals were at the correct thermal height but heading out northeast their was a localised spread of low CumulusX! at about 1350ft.

I think that the Temperature and dew point may have a bearing on this. I had a Temp of 20 deg C with a dew point of 14 deg C which would have brought the presipitation layer down.

I changed the weather to 23 deg C and dew point 2 deg C and the CumulusX! cloud displayed much better.

Other Multiplayers were seeing the same effects and thermal improvements also.

Can anyone actually confirm that FSX Temp and dew point has a bearing on clousd effects in FSX.?

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Interesting! I'm used to setting weather in Condor, where cloud height is inexorably linked to temperature and dewpoint. I tried to duplicate the Condor weather when I made this task for FSX, even to the point of setting the same temp/dewpoint, although it does not appear to have any bearing on cloud height in FSX, i.e. you can set them independently at the weather planner.

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Although it does not appear to have any bearing on cloud height in FSX, i.e. you can set them independently at the weather planner.

This seems to be true, but it could have a bearing on CumulusX! cloud which were at the lower level, FSX clouds were at the correct level.

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Hi all,

CumulusX! does not observe any temperature/dewpoint information, instead it determines the cloud ceiling solely from the prevailing FSX coverage, if any suitable cloud layers can be determined.

Usually this is the lowest cumulus layer, provided by FSX weather. The reason is that the FSX coverage is too frequent inconsistent with the actual temp, so that using the temp would give an irritating picture most of the time.

If there is no cumulus layer in FSX, than CumulusX! gambles a ceiling from the range between the minimum an maximum ceiling given in the CumulusX! settings.

You are of course free to create your own reasonable temp, but it doesn't has any effect on CumulusX!.

When you saw the low cloud layers, you may compare it's ceiling with the range given in CumulusX! settings pane. The values there are MSL. So it can happen, that when there is an area without recgonizable cumulus layer, CumulusX! picks a cloud ceiling from the predefined range. In high level terrain this can lead to apparantly low cloud layers. Please note, that due to the way FSX handles weather definition, there can be quite some areas were FSX reports cloud layers but doesn't show any clouds a specific location, because of the structure in FSX predefined cloud patterns (flocks of clouds with clear regions in between), and vice versa.

In addition, CumulusX! evaluates also the global weather information if local clouds are not found, although FSX does not use it in real weather and custom weather mode. In principle, this is a bug (coming from my limited understanding of the weather engine in the beginning of the project), but I left it this way, because this gives a nice option to influence the "blue sky" behavior, without using the UnBlue option. It's described in the manual. If there was previously a weather setting active, which contained a low cumulus layer in the global weather definition, and you change thereafter to custum weather with local stations, or real weather, then the previous global setting persists in the background. If CumulusX! doesn't find positive cloud information in the local weather, it will request the global data, in order the check cloud existence there. If this is not wanted, please start with weather theme "Clear skies" first before using custom weather or real weather. When saving flights, the entirety of all information will be stored in the WX-file, so this information (including global) will reproduced on loading.

Hope that clarifies and explains the occasional cloud layer deviations sufficiently.

Cheers,

Peter

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