The modifications were conducted by the weather service and the modified radars took the successive names of WSR-1, WSR-1A, WSR-3 and WSR-4, depending on the gradual improvement of hardware.

[1] In August of the same year, the WSR-1 installed at Norfolk, Nebraska proved its usefulness and cost savings by alerting the Elkhorn Valley power system of the approach of thunderstorms.

The Weather Bureau agreed to operate these radars and maintain them in order to alert the public in case of danger, as soon as a visual confirmation was obtained.

[1] It took nearly six years for the network to be fully operational; 17 radars have been modified and installed thanks to the joint efforts of local authorities, the state, federal agencies and a university.

[1] After 1956 the modification of the APS-2F radars in their WSR-1, WSR-1A, WSR-3 and WSR-4 versions was assigned to the Weather Office headquarters which had to move some antennas that had originally been installed to locations where it was difficult to ensure the maintenance.

The WSR-1 to 4 series, the first operational weather radar in the United States, used the AN/APS-2F electronics, including a superheterodyne receiver, but with a larger antenna.

As time progressed and experience with the original design increased, the Weather Bureau felt confident enough to upgrade the WSR-1 to WSR-1A, eventually finalizing on the WSR-3 and WSR-4 model.