Yesterday there were some quite heavy rain storms in the SFO area, perfect stuff for instrument rating practice, and as in most cases when there's a storm in that area the winds favored the runways 19L/19R. I ran ASA and in the "historical" section opted for one download line in the historical static configuration. The zulu time was 1500. on October 13, 2009. The METAR on my avitaion site indicated "KSFO 131456Z 14017G25KT 1 1/2SM +RA BR FEW015 BKN026 OVC032 15/14 A2947", perfect.When everything launched I went to the "Map" page in ASA, and sure enough the weather was very close to the above metar. But when on short approach to 19R, while in similar weather to that above, suddenly the weather cleared as I was about to touch down, and remained clear until I was half way down the runway when it resumed to being the above IMC weather.I played around with this a bit, and always got the same consisent extreme change just at that spot on short final. I even generated my own metar for KSFO and established a perimter of 10 miles (I think I'm right with the perimeter variable, this was yesterday), and I still got fair weather on short final.I'm not sure what is happening. I have default textures, and no other wx engine running. I do have FSUIPC (licensed), but have the wx settings turned off (I only use it for the control functions).Thanks for any info, Bruce.

Hi,When that happens, pause FS and see if ASA is reporting a different station.Sometimes a closer station will show up depending on where the actual weather station is located.I know that might not be true if you use the Wx Config screen and applied the weather.Thanks,

Hi,When that happens, pause FS and see if ASA is reporting a different station.Sometimes a closer station will show up depending on where the actual weather station is located.I know that might not be true if you use the Wx Config screen and applied the weather.Thanks,

Thanks Jim, I have still to try this some more and will do what you suggest. Is it just a matter of deleting the other station if that's the issue? Thanks, Bruce.

Hi,Yes, but I don't think at KSFO this is the case. There would be too many other reports of this.Thanks,

Hi,Yes, but I don't think at KSFO this is the case. There would be too many other reports of this.Thanks,

Thanks Jim.I tried this again today and actually removed FSUIPC, but the issue still remains. Once again, with the metar above loaded:"KSFO 131556Z 18030G39KT 1 1/4SM +RA BR FEW003 OVC027 17/16 A2948 RMK AO2 PK WND 17045/1534 SLP984 P0036 T01670156 $"through the Historical tab (Oct 13, 1600Z), and this same wx showing on the Map page for KSFO, when "position and hold" at runway 19L, I get (in the FSX Weather menu where actual wx is displayed):"Winds 232 15G21, 40sm vis, BKN, temps 57/43, alt 29.71". Moving towards the center of the airport I get the weather in the METAR, as I do when approaching the airport on 19L approach, until about 1 mile from the 19L threshold.Obviously this is not a nearby station :). While I'm sure that this is at my end, would you mind confirming (or anyone reading this) that in the same location you either get the wx I do, or the correct wx?Thanks, Bruce.

Just to remove ASA from this picture, I also get this weather change when setting all weather stations to IFR in the sim itself, where a large chunk of KSFO is VFR/clear when the station has been set to IFR wx. The only way I can get IFR wx at the 19L/R end of the airport is to set it with a theme in FSX. I might try posting in the main FSX forum. ASA is certainly not the cause, but it's still wierd! Thanks, Bruce.