Cloud Elevation - Above Ground or Sea Level ?

[Guest]

I'm a FSMeteo and ActiveSky user and after a couple of months of using ActiveSky I have recently encountered some bad weather on a few of my flights. I have come across a situation when the weather was at zero visabilty and impossible to land as it appeared that the cloud elevation was below the ground elevation. After switching to FSMeteo at the same location the weather appeared to be correct as was reported. I know with FSMeteo that the cloud elevation is compensated for ground elevation. My question is as follows, does ActiveSky compensate for this ground elevation in the weather that is downloaded and if so what is the setting make this happen.Thanks in AdvanceGrant BeachWindow XP ProIntel D850MV MotherboardIntel Pentium 4 2.00 GHz 1000 Mb RAMATI Radeon 9700 Pro 128 MbCH USB YokeCH Pro PedalsGoFlight GF-AC Cockpit Control System2x GF-P8, 2x GF-T8, 2x GF-45, 3x GF166A, 1x GF-MCP & 1x GF-LGTMicroSoft FS2002 / X-Plane 7.00 / Fly! II

[Damian Clark 1,043]

Hi Grant,METAR reports are given in AGL (Above ground level) not MSL (Mean sea level) and of course wxRE knows this. Ground elevation is computed from the icao.txt database. The elevation figure is for the METAR station not the ground you are flying over, which can vary. For example, you are 20nm from station ABCD which is at 4000ft elevation and has report of OVC030. MSL of the cloud base over this station would be 7000. Now lets say you fly into an area (still active ABCD) of higher elevation and land at an airport (not a METAR station) at 6000ft MSL. The OVC base is still 7000MSL based on the METAR station elevation computation but now it is only 1000AGL not 3000 as reported from ABCD. I suspect this may be why your figures are off but you have not specified the details of the METAR report, your distance to it, ground elevation at the airport you landed at etc.. Let me know the details and I can investigate further to see if there is a problem here.Also note that wxRE has random and intelligent variation in all weather including cloud bases so it won't be uncommon for the bases to be off up to a couple hundred feet, as is in real life.Hope that all makes sense.. let me know your details and I can troubleshoot further.. Thanks!-Damian[table border=0" cellspacing="30" cellpadding="0][tr][td align = "left"]Damian ClarkHiFi Simulation SoftwareDeveloper of ActiveSkyThe next-generation weather environment simulation for FS2002!http://hifi.avsim.net/activesky[/td][td]http://hifi.avsim.net/activesky/images/wxrebeta.jpg][/td][/tr][/table://http://hifi.avsim.net/activesky/ima...[/tr][/table

[Guest]

Damian ClarkI may have found the reason for the zero visability I was experiencing - The airport I was landing at had an elevation of 523m in the ICAO.TXT file but according to the Jeppesen SimChart the elevation is 670m, a difference of 147m. I have made the changes to the ICAO.TXT file and will give a try thanks for the info.

[Damian Clark 1,043]

Aha! That would do it.. let me know what METAR station had the error and I will update it in the dist file.. thanks!-Damian[table border=0" cellspacing="30" cellpadding="0][tr][td align = "left"]Damian ClarkHiFi Simulation SoftwareDeveloper of ActiveSkyThe next-generation weather environment simulation for FS2002!http://hifi.avsim.net/activesky[/td][td]http://hifi.avsim.net/activesky/images/wxrebeta.jpg][/td][/tr][/table://http://hifi.avsim.net/activesky/ima...[/tr][/table