Currently we are using forecasted hourly data. PWS do not broadcast forecasts which are derived from weather services that take many factors like radar, satellite, stations, secret sauce, etc.
We use forecasted hourly data for our 12 and one hour weather intelligence skip checks. If we did start using forecasted hourly data for 12 hour checks, and PWS data for current condition checks (one hour) I believe you would have a system that is using two different sources of truth which would ultimately lead to more confusion. I’m still having the team review our options.
Since this feature is “new” we haven’t had time to do data analysis on the results/performance. I’d try 20MPH and see if you get good results. The one drawback of this skip is that you don’t get the schedule back after it is skipped , but in some cases your water would be sprayed all over the sidewalk and driveway so it might be a moot point.