Australia does not have a dedicated "Weather Alert" service as they do in the US and which is supported by many US CB radios.
In Australia some areas have an Early Warning Network tramsitted on UHF CHannel 30
http://www.uhfcb.com.au/UHFCB-Broadcast-Network.php but I have no idea how widespread this is or how reliable.
I have used a weather resistant Uniden UHF076SX on the trail a couple of times when walking with separate parties but no longer do so as it is not worth the weight penalty.