Tropical Storm Imelda hit Southeast Texas this week, causing incredible flooding in much of the region. Some parts of the Houston-Galveston area recorded more than 40 inches of rain, inching toward the records set during Harvey. A flash flood warning was issued from the Texas-Louisiana border, reaching as far west as Fort Bend County. More rain fell in Houston on Thursday than during Hurricane Ike, which hit the region almost exactly 11 years ago.
The tropical storm formed in the Gulf of Mexico on Tuesday and made landfall around 10 p.m. Harris County Flood Control District initially predicted about a foot of rain on Thursday in isolated areas, and the National Weather Service downgraded the storm to a weaker tropical depression. But by Thursday, it was clear that the rainfall was far beyond those initial predictions, particularly in neighboring counties like Jefferson and Chambers, which saw the heaviest rain in the past 72 hours. The governor declared a state of disaster for 13 affected counties that morning.
Tropical Storm Imelda developed and intensified fairly quickly, but was focused on a smaller geographical area than Harvey, says Texas state climatologist John Nielsen-Gammon. Flash floods are hard to predict, since rainfall varies vastly depending on geography, he adds—so evacuations before the storm makes landfall are nearly impossible to plan for.
