I live in Minnesota and it is common in December and January to have temps fall to -15 or -19 below zero fahrenheit. Normally -5 is no big deal but for -15 I need to turn up the heat to stop some cold water lines from freezing. It would be nice if a user could create a pop up alert if the low temp forecast for the next day is expected to be below a user entered custom temp ( or for people in the south maybe above a custom temp). You already have the temps by day in the forecast - just allow a custom alert that can pop up so it is not missed. Same for your separate custom alerts that I separately signed up for to be sent by email to my cell phone. Thanks.
I like your idea and I think it would be a good fit for Weather Watcher Alerts. I made a note to plan on adding it as a feature there.