In mid-April 2016, a large, slow-moving upper-level low emerged from the Four Corners region in Rocky Mountains over the Central United States. Simultaneously, a ridge became anchored over the Eastern United States with another low to the east, creating an omega block—a stagnant weather pattern. The low near the Rockies pulled large quantities of moisture north from the Gulf of Mexico, leading to both heavy snow in the mountains and widespread heavy rain to the plains. During the overnight hours of April 15-18, a nearly stationary mesoscale convective system developed over the Houston Metropolitan Area. Southeasterly flow from a low level jet fueled the system with ample moisture, leading to widespread rainfall rates of per hour. Rainfall intensified throughout the night into the morning of April 18 with rainfall rates reaching per hour, leading to a life-threatening situation. At 4:39 a.m. CDT, a flash flood emergency was declared for parts of Colorado, Waller, Grimes, Montgomery, Harris, and Austin counties, later expanding to Fort Bend.