First Alert Forecast March 21, 2021 7:54 am First Alert Forecast: First Week of Spring After a cool morning, temperatures reach the 70s. Shanna Mendiola has the forecast for Sunday March 21, 2021. US & World Videos 3:47 First Alert Forecast: Warming Up 2:56 First Alert Forecast: Morning clouds and fog 3:20 First Alert Forecast: Weekend outlook 3:37 First Alert Forecast: May Gray to June Gloom 2:40 First Alert Forecast: Clouds won't last long