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Guest aca_dia

I sure wish AS could interpret Vertical Visibility (VV)

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I know I brought this up before, but I have gotten pretty frustrated with this issue. Perhaps I am incorrect and the cause is not lack of VV interpretation. Here is a METAR, Local Radar Shot, and a Fs9 screen all from the same time at KBOS. I am finding the only way I can use ActiveSky to simulate low IFR is to save the weather and then go edit the file and make sure all stations near my flight have overcast(OVC) in place of vertical visibility (VV). KBOS 090204Z 31028G39KT 1/4SM R04R/2800V5500FT +SN FZFG VV002 M08/M11 A2890 RMK AO2 PK WND 31039/0158 P0000 $http://forums.avsim.net/user_files/109154.jpghttp://forums.avsim.net/user_files/109155.jpg

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The ActiveSky METAR when I loaded the weather was pretty much identical to the one above. I think it might have been VV001. On the ground at KBOS I did have low visibility and snow, but the minute I climbed away from the airport it was mostly clear throughout the area (and the airport looked completely clear from above). At the time several other airports also had VV in place of OVC due to super low IMC conditions at the field (KBED to the west and KPSM to the north both were showing VV).Douglas

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Just tried to download the weather from last night off your server. No mater what time I enter I am getting the METAR from 0102Z. No matter as this is close enough to the time used. Below is the METAR from the AS data.KBOS 090102Z 31026G38KT 1/4SM R04R/1000V1800FT +SN FZFG VV001 M08/M09

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It would certainly be worth looking into adding it. In the US most significant airports have equipment for VV reporting. Granted you can get a VV report for morning fog (with no cloud layer above), but the majority of the time it is due to very low IMC conditions. It is very common to have a weather system with low conditions move through an area and half or more of the stations are reporting VV. AS seems to interpret this as being more than half of the stations reporting clear so we end up with the complete opposite weather. One thought would be to use the precipitation info to determine cloud layers (though you often get VV with no precip). As a rule of thumb a cloud layer needs to be 4000

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I would think as a temporary measure at the AS weather server a VV report might be converted to an OC parameter so it would be seen as a cloud layer. With fog layer generation it might work.This make any sense?

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