So as the title says when looking to a rain shaft my fps goes from 40 to 13. It only happens with this condition, not with cloud nor anything just this. I’m using ultra graphics with a 1070 8Gb RAM 16Gb and CPU 4GHz
Start dropping some of those settings too high for your 1070.Drop your super sampling down to 4x.Super Sampling will saturate your vram. My sim slows down the moment I use 6x or 8x here on a 2060super which is faster than a 1070.I run stuff on Ultra too and trust me my 2060super is struggling especially on 1440p.
Your settings are too much for what your GPU can handle.
Use the default settings, if they are Medium (as per your PC specs), then try to increase some of the inputs. As said by MLTAVIATOR99, you have exceeded your PC with those settings.
Don’t forget to limit FPS to 30 in Nvidia control panel.
I assume you have the Nvidia control panel installed.
As I have it in Spanish, the text may not match but it is understandable.
Select control 3d application
Open the Program Settings tab.
Locate Microsoft Flight Simulator
Find Maximum frame rate, activate put 30 and save
For your name it seems that you can be spanish speaker, those are the steps: Seleccionar controlar la aplicacion3d Abrir la pestaña Configuración del programa. Localizar Microsoft Flight Simulator Buscar Velocidad maxima de fotogramas, activar poner 30 y guardar