A cold front making its way down from the north is expected to bring substantial rainfall to the Lawrence area Thursday night into Friday morning, according to the National Weather Service in Topeka.

The rain is expected to begin in Lawrence between 10 p.m. Thursday and midnight, then continue through Friday morning, said Kevin Skow, a meteorologist in Topeka.

The rain — between 1 and 2 inches — should be one prolonged event rather than several storms moving through the area, Skow said. However, isolated, heavier amounts could fall in some areas. A flash flood watch is in effect from 10 p.m. Thursday through Friday afternoon.

Another round of storms was expected to begin forming Friday evening through Saturday, causing more locally heavy rainfall and flash flooding.

Skow said Thursday afternoon that it was too early to know the severity of the storms, but they could include hail and strong winds.

By Sunday the skies should dry out, bringing a mostly sunny Labor Day on Monday with a high of 84 degrees.