Actually, predicting the progress of frontal rainfall is by far the easiest nowcasting problem. The squall lines that develop along cold fronts more-or-less mov

Actually, predicting the progress of frontal rainfall is by far the easiest nowcasting problem. The squall lines that develop along cold fronts more-or-less move in a straight line at a constant speed. They're easy to isolate and track in sequences of imagery using well-developed image processing and segmentation techniques. Their total motion is grossly constrained by large-scale kinematics in the atmosphere. And over short time periods (0-3 hours) individual features/cells embedded in a line are more-or-less persistent. With conventional extrapolation (e.g. DarkSky) you can nail the timing of rain at your location down to about 1-2 minutes by looking at a few sequential radar images, give or take a minute or two if the the edge of the precipitation is a bit more diffuse.