The 36-hour period from Friday evening into Sunday morning will be the most dangerous, as an additional 6 to 12 inches of rain will fall over already drenched areas.
The severe weather system overturned a tractor-trailer in Indiana, killing the driver, and sent a tree crashing onto a car as it was being driven in Michigan, among other damage.
The top official in Hidalgo County issued a disaster declaration after more than a foot of rain fell, causing widespread damage. One death was also reported across the border in Mexico.