There is some conflicting data on the history of Weather Radio Stations.
For example, Wikipedia states this about the Weather Radio station in Buras, Louisiana (which is near the mouth of the Mississippi River):
Broadcasting activities of WXL41 began on August 17, 2005
However, if you were to look at the 1979 Radio Shack Catalog on the page for Weather Radios, you will see "Buras" listed under Louisiana.
I personally wish I could get a detailed history of my local station KIH23 which serves South Central and the western portions of Southeast Louisiana. All I know is that it signed on in 1975 or so...