"Weather Radios" pick up signals from the local NOAA radio station, not from TV stations. »www.nws.noaa.gov/nwr/nwrbro.htm -- It is better to have it and not need it, than to need it and not have it.
There are radios that have multi-band capability. The also happen to have a Wx band built into them.
OP is saying that he used his radio to also pick up TV stations that had weather broadcasts to supplement the NOAA broadcasts. -- "F is for Fire that burns down the whole town... U is for Uranium...... Bombs... N is for NO SURVIVORS!!!!!" Sheldon Plankton