Description

This mod changes the weather chances in the game's regions, including an increasing chance of blight before the Main Quest is completed.
 
There are two versions of the mod, a plugin version and an MWSE version. The MWSE version is more compatible, and additionally allows you to configure the base weather chances for each region. It also includes a "time elapsed" feature (blight chances increase as the days pass before finishing the Main Quest) that the plugin version lacks.

Base Weather Chances

The first set of changes in this mod are changes to the base weather chances in the game's regions, in ways that I think make more sense. This refers to the default/base weather chances, not the increased chance of blight during the Main Quest.
 
In the plugin version, these base weather chances are set in stone unless you modify the plugin. In the MWSE version, the Mod Config Menu allows you to adjust the base weather chances to your liking. (It basically incorporates the functionality of Weather Chances Adjuster).
 
A summary of these changes to weather chances follows:
 
1. Ashstorms (but not blight) are now possible in all regions of Vvardenfell. This includes Sheogorad. Regions closer to Red Mountain have higher chances of ashstorms. Probabilities range from 30% in the Ashlands to 5% in Azura's Coast.
 
2. All weather conditions (other than blight, snow and blizzard) are now possible in all regions of Vvardenfell. For example, rain and thunderstorms were previously not possible in the Ashlands or Molag Amur, and fog and overcast were not possible in the Ascadian Isles. Now they are.
 
3. The chance of fog has generally been lowered. It's now 5% to 10% everywhere, with coastal areas generally having higher chance of fog.
 
4. Rain is now always more likely than thunderstorm, with coastal regions generally having greater chances of these conditions.
 
5. Some of the very high chances in vanilla (for example, 60% for cloudy in the Bitter Coast, and 45% each for clear and cloudy in the Ascadian Isles) have been toned down and distributed to other weather conditions.
 
6. Regions that you'd think would have good weather (such as the Ascadian Isles and the Grazelands) have higher chances of clear and cloudy weather than other regions.
 
7. Red Mountain before finishing the Main Quest is still 100% blight. However, after completing the Main Quest, the weather chances for Red Mountain are different than vanilla. Previously, Red Mountain post-main quest had 50% chances each for clear and cloudy, with no possibility of any other condition. This has been changed to make more sense, with weather chances similar to the Ashlands, but with a somewhat higher chance of ashstorms.
 
8. Mournhold weather chances are the same as in vanilla.
 
9. Snow and blizzard are still not possible anywhere on Vvardenfell, including Sheogorad.
 
10. However, snow and blizzard are now both possible in all regions of Solstheim, including the Hirstaang Forest.
 
11. Snow is now always more likely than blizzard, with northern regions of Solstheim having greater chances of these conditions than southern regions.
 
12. Rain and thunderstorm were previously not possible anywhere on Solstheim; they now have relatively low probabilities in the Hirstaang Forest (some of which is free of snow accumulation), with rain more likely than thunderstorm. These conditions are still not possible further north.
 
13. Fog was previously not possible in a number of Solstheim regions. Now it's possible everywhere, with relatively low chances.
 
14. The southern, more temperate regions have higher chances for the "good" weather conditions like clear and cloudy than northern regions.
 
15. Brodir Grove now has the same weather chances as the Hirstaang Forest, and Thirsk now has the same chances as the Felsaad Coast.
 
16. Weather chances for the Firemoth Region are also different. Previously Firemoth was 100% thunderstorm. Now weather in this region is roughly similar to the Bitter Coast, except for much higher chances of rain and thunderstorm (higher than any other region) and a lower chance of ashstorm (the same as Azura's Coast). Note that this mod does not require Siege at Firemoth.
 
A few notes about the MWSE version:
 
Changes to a region's weather chances will be effective immediately, but that doesn't mean the actual weather will change immediately. The new weather chances won't be used until the game chooses a new weather for that region.
 
In a few cases, the configured weather chances will be overridden. The chances displayed for Red Mountain will only be effective after the Main Quest is complete. Before completing the Main Quest, Red Mountain will be 100% blight. Also, the configurable chances for Mournhold are for "normal" weather, and will be overridden when the weather machine is active during the Tribunal Main Quest.
 
Before the (Vvardenfell) Main Quest is complete, a portion of the base ashstorm chance for any region (except Mournhold) will be converted to blight chance, in increasing amounts as you progress in the Main Quest and as time passes regardless of quest progression. See below for more about this.
 
The Firemoth Region from the Siege at Firemoth official plugin is included in the MCM, so you can adjust the weather chances at Firemoth if you have it installed.

Blight Increase upon Main Quest Progression

The second component of this mod is the addition of changes to weather chances, occuring periodically as you make progress in the Main Quest, which implement the possibility of blight storms outside of Red Mountain.
 
In the plugin version, these changes are also set in stone, and apply to all regions of Vvardenfell outside of Red Mountain, including Sheogorad. Mournhold and Solstheim are not affected by these changes.
 
In the MWSE version, these changes apply to any region (other than Mournhold) which has a base chance of ashstorms. Any region without a base ashstorm chance will not be affected by these changes.
 
These changes lower the chance of ashstorms and correspondingly increase the chance of blight; chances for other weather conditions are not affected. In other words, ashstorms are replaced by blight storms, with increasing frequency as you progress through the Main Quest.
 
Blight chances are increased upon reaching the following milestones:
 
1. Giving the Dwemer Puzzle Box to Hasphat Antabolis.
 
2. Receiving Hassour Zainsubani's notes on the Ashlanders.
 
3. Defeating Dagoth Gares.
 
4. Taking the cure from Divayth Fyr.
 
5. Receiving Moon-and-Star in the Cavern of the Incarnate.
 
6. Receiving (a working) Wraithguard from Vivec or Yagrum Bagarn.

As your conflict with the Sixth House reaches its climax, so too does the influence of Dagoth Ur outside Red Mountain.
 
At their highest (after receiving Wraithguard but before finishing the main quest), in the plugin version, blight probabilities range from 25% in the Ashlands to 4% in Azura's Coast. Regions closer to Red Mountain are more likely to experience blight (because their base chance of ashstorms is also higher).
 
In the MWSE version, the magnitude of these changes is configurable. It depends on a setting in the MCM, the max quest progression factor. This is the percentage of ashstorms that will be replaced by blight storms at the peak of the blight (after receiving Wraithguard but before completing the Main Quest). By default this setting is 90%, meaning at the blight's peak, roughly 90% of ashstorms will be replaced by blight storms (not taking into account how much time has elapsed, for which see below).
 
For example, by default the base chances in the Ashlands are 30% ash, 0% blight. Toward the end of the Main Quest, with default settings, 90% of those ashstorms will be blight storms instead, meaning the new chances will be 3% ash, 27% blight. Earlier in the Main Quest, ash chance will be higher and blight chance lower.

Blight Increase as Time Passes

In addition, in the MWSE version (but not the plugin version), the mere passage of time prior to completing the Main Quest will increase the chances of blight. Dagoth Ur is getting stronger, whether you choose to do something about it or not.
 
The rate of blight increase due to the passage of time depends on two settings in the MCM, the max time elapsed factor, and the "days to max time factor." By default these settings are 75% and 365 days. With these settings, the proportion of ashstorms transformed to blight steadily (and linearly) increases until it reaches 75% (not taking into account Main Quest progression) after 365 days.
 
So, for example, default base chances in Molag Amur are 20% ash, 0% blight. After 365 days have passed, chances in Molag Amur will be 5% ash, 15% blight, assuming no Main Quest progression. After the configured number of days have passed, the time elapsed factor will not continue to increase beyond the max.
 
This time elapsed factor (max 75% by default) and the quest progression factor (max 90% by default) will be added together to determine the actual proportion of ashstorms transformed into blight. This total proportion cannot exceed 100%. Both of these features are configurable in the MCM, and can be disabled by setting the corresponding max factor to 0.
 
Upon finishing the Main Quest, the weather chances for all affected regions are returned to their normal base values. With default settings, ashstorms are still possible throughout Vvardenfell after the Main Quest is complete, but there will be no more blight.
 
The plugin version's addon for Siege at Firemoth also includes the Firemoth region in these changes. The highest chance of blight at Firemoth is 4%. In the MWSE version, Firemoth is affected by these changes like any other region, as long as there is a base chance of ash in Firemoth (which there is by default).
 
Finally, in the plugin version, one more change has been made to weather chances. In vanilla Morrowind, there is an inconsistency in the script on the weather machine under Mournhold. If you set the machine to produce "normal" weather, the resulting weather chances are different than the base chances in the Mournhold region record. Now they're the same. (In the MWSE version, this inconsistency no longer applies.)
 
Both archives contain a spreadsheet detailing all base weather chances both in vanilla and with this mod.

Installation

Plugin version:
 
Use a mod management tool such as Wrye Mash, or just copy the plugin(s) of your choice to your Data Files directory and select them in the Morrowind Launcher.
 
As the base weather chances in the region records do not include blight, it's safe to install this plugin after the main quest is complete. Doing so will not re-introduce blight.
 
However, as savegame files contain references to the game's regions with their weather chances, and as savegame data always overrides plugin data, I recommend starting a new game with this mod to see the new weather chances. (Alternatively, you can use Enchanted Editor to delete the region references from your savegame.)
 
MWSE version:
 
Use a mod management tool such as Wrye Mash, or just copy the MWSE directory to your Data Files directory.
 
This mod can be installed at any point, including in the middle of or after the Main Quest. It does not require a new game, and there's no risk of it reintroducing blight after the Main Quest is complete.

Requirements and Load Order

Plugin version:

This mod requires both Tribunal and Bloodmoon.

If you're using Atmospheric Sound Effects, Morrowind Acoustic Overhaul or Better Sounds, then enable the relevant compatibility patch in addition to the main Creeping Blight plugin. The compatibility patches require their respective mods, and must load after both their respective sound mod and Creeping Blight.
 
If using ASE, I recommend using B00ze's modified version.
 
The MAO compatibility patch is based on the MAO 1.1 plugin.
 
If using Better Sounds, you should use the "fixed and clean" plugin which the compatibility patch is based on. There's no need to use the BM Weather Change plugin, since the compatibility patch incorporates it (with adjusted weather chances, of course).
 
The Firemoth addon requires both the Siege at Firemoth official plugin and the main Creeping Blight plugin, and must load after both. It can be used with any version of Siege at Firemoth (I recommend the UMOPP version).

MWSE version:
 
The MWSE version requires MGE XE and the latest version of MWSE 2.1. Just install MGE XE and run MWSE-Update.exe to download the latest build.

Recommendations

I highly recommend the use of Blighted Blight along with this mod. Blighted Blight implements Bethesda's originally intended mechanic where you can actually contract blight diseases when out in a blight storm. This creates a concrete consequence to the spreading blight.
 
If you're using the MWSE version of Creeping Blight, you might also want to use Dynamic Timescale. The time elapsed component of the increase in blight chances depends on the number of days passed in-game, which will depend heavily on the timescale. Dynamic Timescale slows down the passage of time while exploring dungeons and in civilized areas, while significantly speeding up time in wilderness areas. If you spend a lot of time exploring the wilderness, that's time that Dagoth Ur is using to increase his strength.

Compatibility

The plugin version will conflict with any mod that changes weather chances or otherwise edits regions. (Unfortunately, tes3merge does not merge region records, so it won't help here.) Compatibility patches are included for Atmospheric Sound Effects, Morrowind Acoustic Overhaul and Better Sounds, all of which modify regions to add new sounds.
 
In addition, the plugin modifies the following scripts:
 
CorprusOnPC
EndGame
MoonAndStar
tr_weathmachine
 
There will be conflicts with any mod that edits any of these scripts. (The EndGame script probably presents the greatest potential for conflicts.)

The MWSE version is much more compatible. Creeping Blight MWSE is compatible with mods that edit regions to add new sounds. It's also compatible with Weather Adjuster (as is the plugin version for that matter).
 
However, it will still conflict with any mod that changes weather chances. Such mods will be overridden by this mod. Do not use Weather Chances Adjuster with this mod, as the MWSE version incorporates the functionality of that mod.

Version History

Version 1.1.1 (Plugin version) - 2021-09-19
   - Fixed an issue in the Better Sounds compatibility patch where the name of the Moesring Mountains region was spelled incorrectly.

Version 2.1 (MWSE version) - 2020-06-19
   - Implemented configurable "time elapsed" feature: The chance of blight will now increase as the days pass until you complete the Main Quest.
   - This combines with Main Quest progression to determine chance of blight.
   - Minor MCM and coding improvements.

Version 2.0.1 (MWSE version) - 2020-06-17
   - Config file won't be so bloated anymore.
   - Fixed a typo in the MCM.
   - Various coding improvements. No change to functionality.

Version 2.0 (MWSE version) - 2020-06-16
   - Added MWSE version.

Version 1.1 (Plugin version) - 2020-06-04
   - Added compatibility patches for Morrowind Acoustic Overhaul and Better Sounds.
   - Compatibility plugin for Atmospheric Sound Effects is now a patch (to be used with ASE and the main Creeping Blight plugin) rather than a full version.

Version 1.0 (Plugin version) - 2020-05-01
   - Initial release.

Contact

Feel free to contact me on the Nexus with any comments or suggestions. You can also find me on Discord as Necrolesian#9692.

Usage

You can use this however you want.