Are there not at least four ways of measuring the probability of a worthwhile frost?

1. Deltas. For example, Delta 180C last night was one in twenty.
2. Spreadage. Since dominated by Commercials, should they not have the best pre-info?
3. Crossage. Ditto.
4. One's own daily tracking of the weather maps. Sadly we lack dear departed Ursula's acumen here, but still we can track it and have some idea.

Your own Positions & Views?

TIA & Regards,
Barefoot