I have the 604 which is the US version.
The IC-M604 has 10 pre-programmed weather channels. These are used for monitoring broadcasts from NOAA (Na- tional Oceanographic and Atmospheric Administration.)
The transceiver can automatically detect a weather alert tone on the selected weather channel while receiving the channel, during standby on a regular channel or while scanning. (p. 44)
q Push [CH/WX] once or twice to select a weather channel. ? ?WX? appears when a weather channel is selected.
? ?WX ALERT? appears when the weather alert function is turned
ON. (p. 44)
w Rotate [SELECTOR] to select a channel.
? Pushing the keypad or [Y]/[Z] on the microphone also selects a channel.