There are two main factors to the Thursday storm that will make it more potent than its predecessors. The storm will quickly follow on the heels of a storm on Wednesday, so Southern California and Arizona may not even notice a break between the two systems.
Thursday's storm will also bring a greater danger of widespread and serious flooding. Not only will the storm itself unleash substantial rain, but the ground will not be able to absorb much of the rain. Previous storms will leave the ground extremely oversaturated.
A dangerous situation is definitely taking shape across the Southwest. Be sure to follow any evacuation orders issued by officials, as well as keep away from raging waterways or flooded roads.
Story By AccuWeather.com Senior Meteorologist Kristina Pydynowski