@ ThaMan: For some reason the sync isn't holding over interior/exterior transitions, so either something is releasing the weather override, or something is causing the data to be lost during the transition. Those are the only possibilities if you've got everything installed correctly. Are you Importing Cells into the Bashed Patch?
@ arcwolf: Could you you recap for me again what exactly is the nature of your bug and where it occurs?
ThaMan's issues also happen to me by the way. I didnt want to mention it but since you've jumped on it I'll mention I do see that too.
The scenario for me with this oddity [ I admit this is an extreme case ] is this: Go to Anvil its raining. Enter the Black smith, turn right back around exit. Its now foggy. Turn right back around enter black smith. Turn right back around exit black smith. Its clear day. Turn right back around enter black smith. Turn right back around exit black smith. Its Thunder storm. The issue also occurs randomly if you take your time and go about your business within a shop. So since I dont do the above extreme test under normal circumstances I dont care about it. I'm just leaving that one above alone. Ive seen it too much to care about it. Like for many versions. so ... anyway, if it happens I enter a shop on a sunny day buy some junk and head out and its a downpour I just chalk it up to a cloud burst or blame sheogorath.
If you want to see a log of that issue check the Logs I sent you, Its going to be Log: Without Streamline 2.log around line 354 and 355 you see this
Cell: 0003053B Weather: 02000CE6 Percent: 1.00
Cell: 0000617F Weather: 00038EF1 Percent: 1.00
SO on to the real issue you want to hear about from me, as follows:
A new game. Just AN loaded, Includes Real Lights, EW NW AWS combo and the weather filter. Rest except the Alt Start Mod is vanilla.
{note: Alt Start so I dont have to walk out of that stupid jail yet again. I really doubt it messes with weather. }
{edit: Now that I think about it maybe I had landscape mods in these tests. Like elswyre and xul. But nothing that should mess with weather that I know of anyway. Its been a few days slept since then}
Check log with streamline nopurgeperiod.log
Line 3462 and 3463
Cell: 0000617F Weather: 00038EEE Percent: 0.80
Cell: 0000617F Weather: 02005195 Percent: 1.00
That was an obvious instant transition. In fact its why the log was so short. I got PO'd at the game and had to chill for a while

heh
Other examples are harder to see because the log shows only that the percentage went from 1.00 to 0 but when it hits 0 it changes with a snap. No fade just BAM clear, to Rain. or Rain to fog. Honestly I cant even remember where in the logs insta-transitions occurred now because of that. The logs look normal to me anyway but in amongst them there are instant transitions.
In these tests the issues usually occur on the yellow road running away from Open Cities, Layawiin reborn. Although they can occur when going from the Mage guild side of Leyawiin across the bridge to the castle center island. I've seen them also happen around Anvil and the Brena Cross inn. As well as near Bravil on the Orange Road.
The other one I've talked about was the below. When the weather typically will transition from 00038EF1 to 00038EF2 and back again repeatedly. Transitions occur normally, you can see this in the log without streamline 2.log
Check around the following lines:
951 & 952
4271 & 4272
7388 & 7389
I anticipated it would keep doing that if I had turned around and headed back to Leyawiin. But I kept going and headed on to the Imperial City Isle and made a loop then came back. Normal weather until I believe I came around Bravil area check lines
21617 & 21618
26344 & 26345
29316 & 29317
Having experience with programming I know this is going to be a frustrating issue and make little if any since. So, no rush, I only want to help. Not going to hammer ya or anything. If you need more testing from me please dont hesitate to ask. I'd be glad to.