Tarrant County was awash with rain showers Monday, and more was expected through Tuesday, forecasters said.
An upper-level low pressure system from Canada arrived in the southern plains over the weekend.
The system was in the Texas Panhandle early Monday, said Jennifer Dunn, a meteorologist with the National Weather Service in Fort Worth.
It was sending pulses of energy into North Texas Monday, where a ready supply of moist air from the Gulf of Mexico waited for something to shake it loose.
"The atmosphere is very saturated," she said. "There is a lot of water being held in the atmosphere."
Chances for rain are 70-80 percent through Tuesday when the Canadian system is expected to be over North Texas.
"The majority will stay west and southwest of us," Dunn said. "But there still is a very good chance we could see 1-2 in the Metroplex, possibly even 4 inches, by the time the event is over."