weather January 6, 2023 11:03 am What Is a Bomb Cyclone? The term “bomb cyclone” describes a storm that’s rapidly intensifying. The weather event happens when the atmospheric pressure of the storm drops 24-millibar (the unit that measures atmospheric pressure) in 24 hours. US & World Videos 2:55 Kari's forecast: Rain becomes scattered 2:18 Kari's forecast: Rainy start to the week 3:49 Rain returns to the Bay Area as communities clean up from flooding 3:32 Rob's Forecast: rain chances returning 2:44 Forecast: rain chances returning