Have you seen the word Bomb Cyclone floating around? What exactly is it, and how will it impact California today? Look at this!
A bomb cyclone simply refers to a low pressure system (similar to what we see with hurricanes) that simply deepen in pressure and intensify very quickly over a short period.
There are a lot of dynamics involved, but this is a process that most efficiently happens over water, as favorable atmospheric conditions allow the central low pressure to drop extremely quickly.
In the image below is an atmospheric moisture map, you can see this cyclone pulling in lots of moisture and dragging it into California, which will result in elongated periods of rainfall for their area. This trailing moisture being dragging into California is known as an Atmospheric River. Numerous storm impacts occur when these two atmospheric conditions meet one another.
So what is this process called? Bombogensis. Let's take a look at what that can look like visually. You can see below the storm goes from somewhat of a blob to a very organized spiral formed low pressure storm system.
Bombogensis occurs when the mb pressure drops 24 millibars in a 24 hour period. The momentum in how fast this deepening can occur is a result of the difference between a cold air mass forming over warm waters. The larger that differences, the better that central pressure can drop and bombogensis can occur.
The result of a bomb cyclone in combination with an atmospheric river will bring extended periods of rain to areas that are normally much drier. There will also be strong winds that will become damaging for the Pacific North West Coast along with snow fall for higher elevations.
