Affected areas include Armidale, Tenterfield, Glen Innes and Dorrigo. 

The State Emergency Service advises residents to follow these guidelines. 

* Move your car under cover or away from trees. 

* Secure or put away loose items around your house, yard and balcony. 

* Keep clear of fallen power lines. 

* Unplug computers and appliances. 

* Avoid using the phone during the storm. 

* Stay indoors away from windows, and keep children and pets indoors as well. 

* For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.