Here;s something that I first posted on the ASA/HiFi forum here, but have discovered that ASA is not the cause- which leaves FSX I guess. I'm wondering if anyone has seen this and has a fix?I am at KSFO, 19L threshold. If I set the weather in FSX to IFR (low vis, low clouds, RA+, etc.) in FSX by setting the weather in "User Defined Weather, Customize" selecting "all weather stations", then I find I am in VFR conditions at the 19 L threshold and remain so until I get to the far end of the runway, where the wx changes to what I had set. It's like there is a "weather hole" for a significant part of the KSFO airport.I can get IFR weather at the 19L/R theshold end but need to set a theme in FSX to do so.I initially noticed this in ASA, but the sim itself has the issue too. I do have FSUIPC (registered), but disabled it and noted the same issue. It's a little irritating as usually when there is a storm at SFO the winds favor the 19's, however to fly along in IFR, then suddenly break out into VFR on short final, and stay VFR until almost the other end of the runway is annoying. I'm sure it's some setting that I have set somewhere! Although I have REX it is not controlling weather, I even tried removing it and later re-installing. Very wierd!Thanks for any info, Bruce.

There is a tight clustering of stations in the Bay Area and, in real life, the region has many microclimates: just a few miles away from KSFO the weather can be radically different. I don't think the weather engine is sophisticated enough to handle these variations in such a tight area. Anyhow, that is just my operating theory based on my own observations in other areas. It seems like FSX does best with mesoscale variations.

Whether or not there are a lot of stations at SFO, I believe the OP's point was that, even when he sets user defined weather - which by definition I believe would set the same weather at all stations - he still ends up with a clear day at the start end of 19L.Sorry, don't have any help for you.

Whether or not there are a lot of stations at SFO, I believe the OP's point was that, even when he sets user defined weather - which by definition I believe would set the same weather at all stations - he still ends up with a clear day at the start end of 19L.Sorry, don't have any help for you.

Thanks guys, if someone could just park their a/c at 19L with weather settings IFR by "User Defined Weather, Customize" selecting "all weather stations"", (not by weather theme) and confirm that this is not my unique system, that would be appreciated.I have tried ASA and have found that even by manually setting the KSFO weather to IFR and setting a radius of 15 miles, I still get VFR at KSFO/19L. very wierd!Thanks, Bruce.

Bruce,Going to 'User Defined' weather, then 'Advanced', and then saying 'OK' doesn't do everything. You may need to set your cloud bottom layer (ft). You may also have to define a 'visibility' layer where either you do, or do not, have the visibility down to 0 AGL (or MINUS if at high alt airport). Lift (drag) bottom edge of your visibility layer to 4K or 5K ft to have clear weather at SFO. Or set it to 0 AGL and you will be 'inside' the vis layer and if vis is set to 1/4 mile, then you will be in fog like weather until you climb above the top edge of the vis layer (what ever you set it to). This is the most ignored part of sim. And most mis understood, especially the visibility settings.'Normal' visibility could be bottom of 4600 ft, with top edge at 9999 ft? Then clouds 10000 ft to 19999 ft. Then cirrus (few) 20000 to 28000 ft. Just a suggestion. Then when you want to be 'socked in' all you have to do is change the visibility bottom edges (you don't even need clouds). Everything else (FSUIPC, ETC) stays the same. (Hope this makes my point more 'obvious'). Visibility, Visibility, Visibility. YOU HAVE TO SET IT YOURSELF. ALWAYS. No need to be in the 'dark' about it.Chuck BNapamule