Flash Flooding and Lightning Strike in Michigan, August 9, 1998

A warm and humid airmass blanketed southeast Michigan. Thunderstorms repeatedly developed in the afternoon along a lake breeze boundary off of Lake St Clair. These thunderstorms generated extremely heavy rainfall over a small portion of eastern Macomb County. National Weather Service radar estimated over eight inches of rain in the southern part of Clinton Township, near 15 Mile Road and Gratiot Avenue (M-3). An volunteer observer for a local television station measured 8.16 inches of rain near this location. This rain fell between 1 pm and 430 pm EDT.Substantial urban flooding resulted in southern Clinton Township and southern Mt Clemens. Most roads in the immediate vicinity were closed due to high water, including Gratiot, Harper, Little Mack, and Metro Parkway. Cars stranded on Gratiot were up to their windshields in water, and numerous homes had flooded yards and basements. Minor urban flooding also took place in adjacent Harrison Township. More serious flooding in the area was averted because the areal extent of heavy rain was extremely small.In the late afternoon and early evening hours, a band of showers and thunderstorms produced heavy rain in southern Oakland County. Rainfall amounts were generally less than two inches; however, this area had seen flood-producing rainfall just three days previous, and was thus vulnerable to any additional rain. High water closed many roads in southern Oakland County, with most of the flooding problems near the I-696 corridor.Lightning struck the Shiawassee County complex early in the evening. The strike damaged computers, heating and cooling systems, and elevators at the courthouse.