September 10th and 12th – Sonoma County is conducting Emergency Alert Tests. September 10: Sonoma County will use SoCoAlert to call everyone who is subscribed and all landlines in the county. You can sign up for SoCoAlert.com or call 866-939-0911. September 12: Sonoma County will send TEST Wireless Emergency Alerts to cell phones in Roseland, Healdsburg, Guerneville, Penngrove and Glen Ellen/Kenwood. There will also be a broadcast of the test on local television and radio.