Facebook
https://www.facebook.com/pages/Brush-Fire-Partyline-San-Diego-East-County/151582704905193
https://www.facebook.com/pages/Brush-Fire-Partyline-San-Diego-North-County/292656327414579?ref=hl
East County is the best
Twitter
https://twitter.com/ViejasAlerts
A lot of the Fire departments have twitter or Facebook but they are usually slow to post.