Severe Thunderstorm at Mt Isa dumped more than 60 mm of rain with winds up to 67 km/hr. Report form train near Kurbaya (40km south Mt Isa) stated very strong winds with hail 1/2 inch diameter with the odd large stone to golf ball size. Dry creek beds crossed before the storm were reported 1hr later to be only 1foot under the railway bridges. Driver could only just see the front of the train engine at height of storm.