From the National Weather Service Des Moines website:

Boone county residents (especially residents in Northwest Boone county), may now tune their receivers to WXK-84 broadcasting from Fort Dodge. This broadcast will now provide severe weather Watches and Warnings for Boone county. WXK-84 at Fort Dodge broadcasts on 162.400 MHz.

Boone county has been, and will continue to be served by WXL-57 at Des Moines which transmits on 162.550 MHz. Those listeners who find that WXL-57 provides the strongest signal should continue to tune to this channel.

Listeners who find that the WXK-84 provides the strongest signal (especially in Northwest Boone county)should tune their receivers to 162.400 MHz.

WXK-84 transmits on 162.400 MHz and serves the following counties.

Boone
Calhoun
Hamilton
Humboldt
Pocahontas
Webster
Wright