gdavej

Yes, that did the trick. Looks like P3Dv2.5 is in need of another hotfix. I guess this problem affects every weather preset, I thought I'd seen some behaviour in your weather themes that didn't seem to tally with the description, obviously this is the cause of that too. Many thanks for tracking it down.

The issue has to have been caused by either PrecipitFX or 777Immersion, since it wasn't present before I installed those products. In addition, the effect I'm seeing appears to be typical of the intended effect of PreciptFX, albeit a rather magnified effect. The product might have been out for 10 months, but that doesn't imply the code is 100% bug free... I work in software development and I know there is no such thing as bug-free code.I would appreciate some assistance in tracking down this problem, since I am not prepared to spend a week re-installing P3Dv2.5 with all sceneries and aircraft I currently have installed.

I uninstalled PrecipitFX, and I still see the issue with the Mustang. I also uninstalled 777 Immersion, although I noticed that the additional weather themes still existed after the uninstall, so I'm not sure how effective the uninstall process was. I can't believe though that this issue is caused by some other addon, since all I've installed are aircraft and sceneries, and I didn't notice the problem until after I'd installed PrecipitFX.

I tried cycling through all the weather themes, and they all seemed okay other than the Fair weather theme, which unfortunately is the one I always use. It was this theme that gave me the sudden onset of rain. I tried loading a Warbirdsim Mustang and using the Fair Weather theme, and this gave the following effect: Obviously, with that cloud on the front fuselage obscuring the view from the cockpit, the plane is practically unflyable. I also bought the 777 Immersion package and installed that at the same time... don't know if this has any impact? I can see that this package did install 3 additional weather themes. Not sure what you mean when you ask "Have you changed it manually before?" When I create a simple scenario, I just select aircraft, location, weather (almost always FairWeather) and fly. And of course, I didn't notice any issues before installing PrecipitFX.

I just purchased PrecipitFX and installed it in P3Dv2.5, I initially installed all 4 effects. I'm getting a couple of issues: The first issue: without using any weather engine, and selecting the Fair Weather theme in P3D, whilst in the aircraft, rain suddenly starts falling for a brief while. This has happened a couple of times, most notably when I was sat on the runway at Doha in Qatar... not a place renowned for it's monsoon season! The second issue seemed to be caused by the Contrails effect. Directly behind the aircraft, whilst on the runway, I would see a large cloud appear, this happened both with propeller aircraft like the Constellation and a Jet fighter like the F16. At one time, whilst on the runway at Dallas Fort Worth, I saw some foggy cloud away from the aircraft around the terminal buildings. These effects can be seen below. When I uninstalled the contrails effect, the foggy cloud did not show.