AtmosFear is a mod for S.T.A.L.K.E.R. - Call Of Pripyat that tweaks and expands the vanilla weather system to be more realistic and various.
A description of the new features of upcoming AtmosFear 3
Posted by CrommCruac on Jun 3rd, 2011
As you certainly noticed Call of Pripyat has reversed east-west sun position that couln't be changed. Thanks to Kolmogor who amended FDL renderers AtmosFear 3 will have the correct sun position. The sun position will be accurate for Chernobyl geographical position on 15 Aug. This give slightly longer nights.
Kolmogor's fix allows to create real moon that casts dynamic shadows. The moon will change the phases in 28 day cycle of faster 8day cycle.
Psi storms are the new kind of weather anomaly that is very dangerous to unequipped stalkers. Psi radiation cumulates in vortexes which generate high psi levels when they discharge. Decent armor/drugs protection reduces the mind damage but the vortexes are still dangerous as they generate hi-voltage electrostatic damage in close distance. Vortexes could spawn artefacts (although possibility to spawn is quite low - 5%) so after the psi storm don't forget to sweep the area with your detector.
Annoyed by the rain from the clear sky? In AtmosFear 3 it won't be possible. It will feature smooth weather transitions so before it rains the sky will become cloudy.
Everything customizable. AtmosFear 3 could be customized from in-game options window without the need of reinstalling or starting the new game. There will be options for weather balance, periods length, NPC fate during the events, event warnings etc.
NPCs will run for cover during events like blowout, fallout or psi storm. They also could be hurt by those events if they stay in the open.
During the events the protection from armor, helmets and drugs will be effective. It means with decent armor (e.g SEVA) and after using the protector drugs it will be possible to walk almost unharmed during the fallouts or psi storms.