by Nina Peyrat

In late December, a series of storms started to hit California. These storms were called  “bomb cyclones” and “atmospheric rivers.” 

Bomb cyclones are large and intense storms that cause heavy rain and strong winds. Cyclones are large columns of air. Regular cyclones are made when high pressure air meets low pressure air. Bomb cyclones are made when the low air pressure drops before being met with high pressure air. This makes the cyclone more intensified. The columns of bomb cyclones rise super quickly before abruptly dropping in air pressure in the center of the column. It forms a vacuum-like effect, causing strong winds. These drops in air pressure are a result of the temperature changes. That is why bomb cyclones are more common in the winter months. 

Atmospheric rivers are currents in the air that carry water vapor. They can be as big as 15 times the size of the Mississippi River. They carry so much water vapor that when released, can form intense amounts of snow and rain. The smaller atmospheric rivers are actually really good. They can replenish our water supply and provide the water needed for living things to survive. But the larger ones are capable of causing flooding and mudslides. 

In California this past month, these bomb cyclones and atmospheric rivers have caused an extreme amount of damage. They have caused heavy rains, mudslides, high winds, flooding, and power outages. Many rivers have overflowed and highways are completely covered with water. In areas of higher elevation, these storms have caused snowfall up to eight inches. In Los Angeles, the temperature dropped to 32 degrees after being at 70 degrees in the weeks leading up to the storm. 12 million residents have received flood watches and some areas have even received freeze warnings. One of the Southern California piers has shut down for repairs after it was hit with high tides and overwhelming winds. At least six people have died from the storms. 

There is a large concern for the places that the wildfires have hit. Because of all of the droughts in California, the strong winds of this storm uprooted many of the trees that were weakened by the long droughts. This resulted in roadway blocks and power lines being down. Scientists predict that because of climate change, these rivers will continue to grow in size and we will witness increasingly larger storms. The warmer air and water from climate change will cause more water to evaporate, giving the atmosphere more water for rainfall.