An upper level low pressure system was entrenched in the western Great Lakes, maintaining cool air aloft across the region.  Thunderstorms developed in the heat of the day, with the most widespread activity developing along the Lake Michigan lake breeze boundary in western lower Michigan.  These storms organized as they moved slowly but steadily eastward, evolving into a squall line that crossed southeast Michigan in the late afternoon and early evening hours.Several of the thunderstorms became severe.  Only a couple of storms produced damaging wind; large hail was the most common type of severe weather.  An isolated storm ahead of the squall line produced silver dollar sized hail in Shelby Township (Macomb County); this was the largest hail report of the day.  The same storm downed trees in that area.  Trees were also downed in Bancroft due to severe thunderstorm winds.  The rest of the severe weather was composed of dime to quarter sized hail events.For some parts of southeast Michigan - particularly metro Detroit - this was the third straight day of thunderstorm activity.  As mentioned above, the storms tended to move slowly, and thus dumped very heavy rain.  Macomb County had seen another batch of storms earlier on the 28th; rainfall totals in the central part of county were as high as five and a half inches.   Another nearly stationary cluster of storms produced 4 to 5 inches of rain near Saline and Milan.  Runoff from these downpours produced flash flooding across parts of the area.Interstate 94 was closed near Chelsea due to flooding.  Many streets in and around Saline flooded, and the Saline River rose out of its banks.  Urban flooding was widespread in Detroit, with many freeways closed, and some industrial facilities flooded.  In Novi, a stranded family was rescued by a boat after their car stalled in flood waters.  Davison Lake Road in Lapeer County was washed out south of Metamora, while water was several feet deep across roads in Almont and Imlay City.  In Almont, the flood waters approached the front doors of homes and businesses.

Flash Flood in WASHTENAW, MICHIGAN
From 28-JUL-00 16:36:00 to 28-JUL-00 18:30:00 (EST)
Location: CHELSEA
Property damage: 20K
Reported by: TRAINED SPOTTER

Flash Flood in WAYNE, MICHIGAN
From 28-JUL-00 18:30:00 to 29-JUL-00 00:30:00 (EST)
Location: DETROIT
Property damage: 150K
Reported by: LAW ENFORCEMENT

Flash Flood in MACOMB, MICHIGAN
From 28-JUL-00 19:10:00 to 28-JUL-00 21:15:00 (EST)
Location: COUNTYWIDE
Property damage: 25K
Reported by: LAW ENFORCEMENT

Flash Flood in OAKLAND, MICHIGAN
From 28-JUL-00 18:25:00 to 28-JUL-00 21:15:00 (EST)
Location: NOVI
Property damage: 25K
Reported by: TRAINED SPOTTER

Flash Flood in LAPEER, MICHIGAN
From 28-JUL-00 18:35:00 to 28-JUL-00 21:15:00 (EST)
Location: METAMORA
Property damage: 50K
Reported by: TRAINED SPOTTER

Hail in MACOMB, MICHIGAN
From 28-JUL-00 14:35:00 to 28-JUL-00 14:35:00 (EST)
Location: UTICA
Magnitude: 1.50 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in MACOMB, MICHIGAN
From 28-JUL-00 14:35:00 to 28-JUL-00 14:35:00 (EST)
Location: UTICA
Magnitude: 52 E
Property damage: 6K
Reported by: TRAINED SPOTTER

Thunderstorm Wind in SHIAWASSEE, MICHIGAN
From 28-JUL-00 15:30:00 to 28-JUL-00 15:30:00 (EST)
Location: BANCROFT
Magnitude: 52 E
Property damage: 5K
Reported by: LAW ENFORCEMENT

Hail in WASHTENAW, MICHIGAN
From 28-JUL-00 15:40:00 to 28-JUL-00 15:40:00 (EST)
Location: SALINE
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in WASHTENAW, MICHIGAN
From 28-JUL-00 15:56:00 to 28-JUL-00 15:56:00 (EST)
Location: SALINE
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in LIVINGSTON, MICHIGAN
From 28-JUL-00 15:59:00 to 28-JUL-00 15:59:00 (EST)
Location: FOWLERVILLE
Magnitude: 0.75 
Reported by: BROADCAST MEDIA

Hail in LENAWEE, MICHIGAN
From 28-JUL-00 16:20:00 to 28-JUL-00 16:20:00 (EST)
Location: CLINTON
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in WAYNE, MICHIGAN
From 28-JUL-00 17:25:00 to 28-JUL-00 17:25:00 (EST)
Location: LIVONIA
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Hail in OAKLAND, MICHIGAN
From 28-JUL-00 17:42:00 to 28-JUL-00 17:51:00 (EST)
Location: BIRMINGHAM
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Hail in ST. CLAIR, MICHIGAN
From 28-JUL-00 17:21:00 to 28-JUL-00 17:21:00 (EST)
Location: YALE
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in LAPEER, MICHIGAN
From 28-JUL-00 18:21:00 to 28-JUL-00 18:27:00 (EST)
Location: ALMONT
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Lightning in MACOMB, MICHIGAN
From 28-JUL-00 19:05:00 to 28-JUL-00 19:05:00 (EST)
Location: ROMEO
Property damage: 1M
Reported by: NEWSPAPER

A lightning strike started a fire that destroyed an automall.