@StephenVDK
You can always just disregard a number of yweather:forecast lines until finding the days ahead that you're looking for. Some
(?:<yweather:forecast[^\n]*\n){3}<yweather:forecast[^\n]*low="(\d*)
for instance would be the fourth item, or the third day forecast. You could control it with the {1,2,3....}. I just recently requested adding capture group number to HTTP retriever specifically so that you could use backreferences on forecast information to make it feel like a reasonable regex.