SOUTH MISSISSIPPI (WLOX) - Our windy conditions this week are thanks to a strong extratropical system which is impacting the central and east U.S.
This is a different type of system compared to the tropical systems that normally affect us in the warm season.
Extratropical systems commonly move from west to east across the U.S., sometimes as frequently as once a week during the winter season.
They are marked with a red 'L' on the weather map and should be very familiar to you since every time a cold front passes through South Mississippi, it’s almost always attached to an extratropical system.
The difference between tropical systems and extratropical systems has to do with their structure and their ability to strengthen.
Tropical systems tap into warm water and can get very strong very quickly. Some go from tropical storm to cat 4 hurricane in a day or so. The strongest thunderstorm activity is usually confined to their centers.
Extratropical systems can spread significant impacts far away from their centers. While most don’t strengthen quickly, this one sure did!
You may have heard the major storm affecting the country this week referred to as a “bomb cyclone.” It was called a “bomb” because of how quickly the system’s barometric air pressure dropped in a short amount of time.
In North America, a “bomb” cyclone or bomb system is defined as when the central barometric air pressure in a system decreases by 24 millibars or more in 24 hours. This process is the extratropical equivalent of when tropical systems undergo rapid intensification.
Although their structure is totally different from that of tropical systems, bomb systems can produce winds as strong as category one or two of the Saffir-Simpson scale and they can produce heavy precipitation.
These strong winds can affect areas far away from the system’s center. And it’s why even though the center of the system has been well to our west, we have been windy anyway right here on the Gulf Coast.