Quote Originally Posted by dawgday166 View Post
So when TV forecaster says it will hit you at ... say at 12:42 am ... does this mean it's really more like 12:36 instead?

I would think their SW model calculations would take into account all the variables you typed in your description above.

Appreciate it dude!
Most of the time they'll only put those tracks up right after a scan update. But even then, most will say those are approximations. Storms speed up, slow down, and change direction. All can make a difference on when they arrive. But just for an example I pulled up my radar app on my phone and it was 7 minutes behind. I changed radars and it was 3 behind. So just those two at random had an average lag of 5 minutes. The reason for the lag is that one radar image you see is actually about 4 images stacked on each other. The radar makes a scan at different degrees. Each scan is called a tilt. The lowest angle, or tilt, 0.5 degrees. I'm drawing a blank at the others but it's done to give a look at much of the storm as possible. It takes time for the radar to make a scan, adjust up to the next tilt, make a scan, rinse and repeat through all four scans. Then it has to process that information and send it out to all the radar apps and software at news studios.