Why does AM radio signal seem to be weaker than it used to be?

Episode 1384 (2:14:05)

Tom from San Dimas, CA
Waze

Tom is a truck driver and relies on AM radio for traffic conditions, but he's had more difficulty picking up stations lately. He's wondering if the stations aren't broadcasting as strong of a signal these days. Leo says that the signal should be just as strong. The way that we hear AM radio over a long distance varies on the weather, because the signal is actually skipping off the atmosphere as it's traveling. When the atmosphere is just right, it will skip off of it and enable him to hear distant stations. If Tom is saying he can't hear local stations, then Leo would guess that's our modern world creating more interference than ever before.

Leo suggests using the Waze app for traffic in addition to listening to AM radio. It's crowd-sourced traffic information.