It's not a question of "if," forecasters say.

It's a question of where heavy thunderstorms will form today in the Carolinas.

Yet another day of slow-moving storms is expected, with another threat of flash flooding and dangerous lightning strikes.

This is in the wake of Wednesday evening's storms, which pounded southern Mecklenburg and western Union counties, causing flooding and several cases in which houses were struck by lightning.

Earlier in the day, thunderstorms dropped heavy rain on portions of Stanly, Anson, Richmond and Montgomery counties, causing brief flash flooding there.

Thunderstorms have caused episodes of flooding on a daily basis since Monday, and one automated rain gage -- at Alexander Graham Middle School in the Myers Park area -- has recorded more than 7 inches of rain over a three-day period.

Forecasters say it is impossible to predict exactly which area will be hammered today, but they say the same type of scenario is likely, given the humid and unstable atmosphere in place across the region.

"With the above-normal temperatures and very moist air mass in place, moderate instability will develop once again," said Rodney Hinson, of the National Weather Service office in Greer, S.C.

Temperatures are expected to climb into the upper 80s today before storms develop. Similar conditions are forecast for Friday. Saturday will be hot, with highs in the low 90s and a slightly lower chance of storms. But the thunderstorm chances will increase Sunday, when a cold front approaches the region.

Wednesday night's storms dropped between 1.5 and 3 inches of rain over south and southeast Mecklenburg County and northern and western Union County.

About 3 inches of rain was recorded in the Myers Park area, with 2 1/2 inches near Ballantyne, and 1 3/4 inches near SouthPark and in Matthews. More than 2 inches fell at Wesley Chapel and Indian Trail in Union County.

Authorities reported Dells Creek spilled out of its banks onto two streets off Rama Road in southeast Charlotte, and a creek flooded Willhaven Drive off Randolph Road nearby.

Lightning struck homes on Watersreach Lane, Providence Hills Drive and Redstone Mountain Lane, but no injuries were reported in any of those cases.