I dunno if this will help.
I usually use the following for my weather pattern specially in Prime Roots:
Pattern 1 combo: Fair (Windy,Fair,Sap) + time (am,pm)
Pattern 2 combe: Sap (Windy,Fair,Sap) + time (am,pm)
Fair Windy am
Fair Fair am
Fair Sap am
I use the above pattern since there are 2 weather in Prime Root (Fair,Sap) and also I don't know programming so I can not decode the source code of Rzyom even if it is available. Windy,Fair,Sap are weather effects in Prime Roots (my observation I don't know if we have same weather effects).
How do I use my pattern:
Prospect using the above pattern combo until I got the desired output and mark my map according to the pattern combo and the grade of the mats.
Zun FWAS, FFAE
FWAS = Fair Windy AM Supreme will pop
FFAE = Fair Fair AM Excellent will pop
note: I still use bmsite for the availability of the mats in every season since I never include it in my map marking.
You can think of there being 4 weather patterns in PR for non-SN sups:
2 season sups pop from Best to Good
4 season sups pop at worst and above
The other 2 weathers correspond to 1 season sups.
One, and only one, weather type is always up, if you know the weather type you know which sups will pop (if not depleted).
LoC and US sup zun pop at worst, and SCi and FD pop at best to good.
Map and on screen weather are a mess, but there is also the possibility that onscreen and map weather were only intended to be a clue that mats could pop at this time, not that they would 100%. BM weather seems to be informantion that players were never intended have access to.