This is a question, probably for Chris Willis.Browsing the texture options in AS Graphics, I note that none of the options for either overcast or broken cirrus show very much cloud as a percentage of the sky, in fact there doesn't seem to be much difference from the options for few or scattered cirrus. Surely overcast is what it says, no sky visible only cloud? I have set up ASG themes with the thickest looking options but there doesn't seem to be much cloud when you use Overcast at say 25000 in a metar to set up a weather template in the configurator and apply it to all stations. Am I missing something?Mervyn

Hi Mervyn,Cirrus clouds only cover the direct FS9 station region (16km^2) and are not subject to FS9 interpolation. Thus, for example, if you are setting a cirrus layer i.e. OVC250 at KLAX, you'll only see a fairly round section of clouds directly above KLAX, with an apparent diameter of only about 10nm.Even if you set every station in the region, you are going to see plenty of gaps, as only the direct station regions will depict the layers.This is a limitation of FS9 cirrus cloud depiction, something we are hoping that FSX improves! Best,

Thanks for that Damian,I don't doubt what you say but FS9 limitations have been cited for every question I have asked in this forum. This one seems bizarre in the extreme. If the explanation in this case is correct there would be no cirrus except on the horizon when I am 50 or 100 miles from the nearest station (a common occurrence in the regions I fly in). I must check that out next time I'm in the Himalayas or New Zealand. I will also look up when I'm at the station to see if there is a patch of cirrus overhead. I can't say I have ever noticed it. I still don't understand why there is no real difference between the textures for scattered and ovc cirrus, but perhaps your preview images are what you get when FS9 has finished with them, not the textures themselves. Roll on FSX.Mervyn

Actually I must have been lying when I wrote about not doubting what you said because I've checked it out as I suggested and there is plenty of overhead cirrus in the Himalayas - see attached screenshot 53 miles from the nearest station - and a second flight at a station where ASV6 says the nearest station was 0 miles showed exactly the same cirrus overhead and around the horizon. In the second case, not shown, there were undoubtedly other stations in the vicinity but the similarity of cirrus forms with the first case suggests that FS9 does produce cirrus over the whole sky dome.Mervyn;-)

Hi,Well this is perplexing. We've done many tests in the past and thus my comments per my experience. I just went in and added a single 25K cirrus level at a single station, and did indeed find interpolation (with various cirrus 'patches') out to about 15nm from the station, but clear everywhere else from 15nm to 150nm, at least in the areas I quickly looked via slew. I could not duplicate any cirrus more than 15nm from the station like your shot here but I'm sure it's possible given the interp system DOES seem to be going active on cirrus.Obviously there are some unknown influences on the cirrus depiction that probably have to do with various factors (altitudes, thicknesses, station locations, other station weather settings?). I'll let Chris chime in some more while I do some further investigation.Concerning differences in the depicted "patches" themselves based on coverage settings, I was under the impression that you were experiencing gaps between the patches and not within the patches themselves. Sorry for the mix-up. Chris, can you verify and follow up on this?Best,

Hi,Any thoughts Chris?Mervyn

I'll drop him a note to stop by!Hope this helps,Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/

HI Mervyn,"I note that none of the options for either overcast or broken cirrus show very much cloud as a percentage of the sky, in fact there doesn't seem to be much difference from the options for few or scattered cirrusThe percentage of cirrus is made from Fs9, Fs9 will show cirrus in a "box patch" in the sky most of the time, unless there is 2 or 3 layer togheter with different formation, like few, scattered and broken togheter they will covers more the sky, others than that's you will see cirrus "box patch" in the sky, limitation of Fs9.ThanksChris Willishttp://www.hifisim.comhttp://sales.hifisim.com/pub-download/asv6...development.jpg

Hi Chris, Thanks for that (and thanks Jim!). My example (reply #3) was a template with SCT 230 BKN 250 as the only cloud, which seemed to give a reasonable spread of cirrus. I must admit I haven't tried an example with OVC. I constructed these templates because I wasn't seeing much cirrus from online weather (earlier thread) but that was largely because most of the time it is not 'significant' in reporting terms so is not put in the metar. I don't think I have never seen the "box patch" effect. As the amount of cloud is constructed by FS9, why do we have different texture options in ASG for the different amounts? Is that so we can have different forms in the sky at the same time with multilayers? There are very distinctive differences between the cloud forms of cirrus in the international classification, e.g between standard wispy cirrus (type 1 say), cirrostratus and cirrocumulus but I don't see this range expressed in the texture options. I know the configurator only allows the cloud to be specified via a metar, which doesn't these days give cloud type, so it is not obvious when specifying a level whether cirrus will appear. Does FS9 have a base height above which all layers are assumed to be cirrus, or is it more complex (e.g. varying with latitude)? My template has occasionally given me a high layer of shallow cumuliform clouds for the FL230 layer instead of cirrus. I would be greatful for your insight.Mervyn

Hi Mervyn,--Does FS9 have a base height above which all layers are assumed to be cirrus, or is it more complex (e.g. varying with latitude)? My template has occasionally given me a high layer of shallow cumuliform clouds for the FL230 layer instead of cirrus. I would be greatful for your insight.--I am not certain on the details of FS9's cirrus logic, which appears to be based on fairly fixed altitude with a bit of variation, but we use our own logic and aloft temperature is the biggest influence, but there are other factors as well (some random). There is no fixed altitude based on latitude.Best,