Lightning-laced thunderstorms rolled through Tarrant County late Tuesday into early Wednesday, drenching much of the area.Rainfall at Dallas/Fort Worth Airport totaled 1.97 inches through 6 a.m. Normal rainfall for the area through Aug. 15 is .97 inches. Normal rainfall for the entire month is 1.91 inches. National Weather Service radar at 6 a.m. Wednesday indicated rainfall totals of up to three inches for much of northeast Tarrant County. A flash flood warning was in effect until 7 a.m. for that area.Most of the county had received at least an inch of rain, radar indicated. Some areas of southeast Wise County and southwest Denton County had received up to five inches.Oncor, which delivers electricity for much of North Texas, was reporting on its website almost 3,000 customers without power in Tarrant County at 6 a.m. Just under 19,000 customers were without power at that time in Dallas County.The storms moved into Tarrant County about 8 p.m. and "averaged two to three [lightning] strikes per minute," said meteorologist Nick Hampshire of the weather service."A stalled frontal boundary over the Metroplex and an upper level disturbance combined together to develop the thunderstorm," Hampshire said.The lightning was accompanied by heavy winds and downpours and brought some heat relief as the temperature dropped into the 70s.The day's high of 106 tied the record for the date set in 1911.The heavy rain helped completely douse grass fires in Fort Worth that developed Tuesday afternoon. The fires were on Angle Avenue, North Riverside Drive and North Tarrant Parkway.By 6:30 p.m., all were under control and firefighters were "mopping up," battalion chief Richard Harrison said.The weather service's Fort Worth office had a clear view of one of the fires and posted a photo online.The forecast calls for temperatures tin the upper 90s Wednesday and Thursday, but a cool front should arrive Thursday night and with it a 30 percent chance of rain.The high on Friday during the day will be in the mid-90s and should be a bit lower for the weekend.