As the deadly floodwaters in parts of central Texas recede, there are growing questions about how the catastrophic rainfall seemingly caught the area by surprise. Some local officials say the National Weather Service underestimated the extreme rain but the agency says an initial flood watch was issued Thursday afternoon.

NWS says Flash Flood Warnings were issued on July 3 and early July 4 in Central Texas, giving more than three hours of warning.

Heavy rains fell quickly in the predawn hours of Friday in the Texas Hill Country, causing the Gaudalupe River to rise 26 feet in just 45 minutes.

Texas Hill Country, where much of the flooding took place this time, is often referred to as “flash flood alley.” It's home to steep terrain and a lack of vegetation that creates a perfect storm for waters to rise quickly.