A very warm, moist and unstable airmass was in place on July 4th. This lead to a few early morning storms which developed along the lake shores, including one that briefly produced severe winds in Algonac. Skies then cleared out during the morning of the 4th, allowing temperatures to soar into the upper 80s and lower 90s across southeast Michigan. Meanwhile, an  MCS developed over MN during the overnight hours of July 3rd and quickly raced southeast. This thunderstorm complex moved through Lower Michigan during the late morning hours of the 4th. The very unstable airmass over southeast Michigan allowed the squall line to intensify as it moved through. Severe wind reports occurred from I-69 and points south. There was also one report of severe hail in Northville. The entire event lasted around two hours, leaving 170,000 customers in southeast Michigan without power.

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:21:00 to 04-JUL-03 12:21:00 (EST)
Location: DETROIT
Magnitude: 55 MG
Reported by: UTILITY COMPANY

Thunderstorm Wind in MACOMB, MICHIGAN
From 04-JUL-03 12:40:00 to 04-JUL-03 12:40:00 (EST)
Location: RAY CENTER
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported a large tree blown down.

Thunderstorm Wind in MACOMB, MICHIGAN
From 04-JUL-03 12:35:00 to 04-JUL-03 12:35:00 (EST)
Location: MACOMB
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large limbs down.

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:26:00 to 04-JUL-03 12:26:00 (EST)
Location: DETROIT
Magnitude: 56 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large tree limbs down.

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:11:00 to 04-JUL-03 12:11:00 (EST)
Location: DETROIT
Magnitude: 52 EG
Reported by: METEOROLOGIST(NON NWS)

A local television meteorologist reported a large tree blown down.

Thunderstorm Wind in MACOMB, MICHIGAN
From 04-JUL-03 12:50:00 to 04-JUL-03 12:50:00 (EST)
Location: CADY
Magnitude: 55 EG
Reported by: NEWSPAPER

A large maple tree was blown down. The tree knocked out power and landed on a house.

Thunderstorm Wind in SHIAWASSEE, MICHIGAN
From 04-JUL-03 11:30:00 to 04-JUL-03 11:30:00 (EST)
Location: CORUNNA
Magnitude: 52 EG
Reported by: NEWSPAPER

Thunderstorm winds downed numerous trees and power lines.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:13:00 to 04-JUL-03 12:13:00 (EST)
Location: BLOOMFIELD HILLS
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large limbs down.

Hail in WAYNE, MICHIGAN
From 04-JUL-03 12:10:00 to 04-JUL-03 12:10:00 (EST)
Location: NORTHVILLE
Magnitude: 1.00 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:16:00 to 04-JUL-03 12:16:00 (EST)
Location: WYANDOTTE
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported tree and power lines blown down.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:20:00 to 04-JUL-03 12:20:00 (EST)
Location: BERKLEY
Magnitude: 56 EG
Reported by: TRAINED SPOTTER

Thunderstorm Wind in GENESEE, MICHIGAN
From 04-JUL-03 11:44:00 to 04-JUL-03 11:44:00 (EST)
Location: FLINT
Magnitude: 54 MG
Reported by: TRAINED SPOTTER

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 13:00:00 to 04-JUL-03 13:00:00 (EST)
Location: KIMBALL
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large tree limbs down, as well as shingles off a roof.

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 13:06:00 to 04-JUL-03 13:06:00 (EST)
Location: ALGONAC
Magnitude: 52 EG
Reported by: LAW ENFORCEMENT

Law enforcement reported trees and power lines blown down.

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 13:05:00 to 04-JUL-03 13:05:00 (EST)
Location: MARINE CITY
Magnitude: 52 EG
Reported by: LAW ENFORCEMENT

Law enforcement reported numerous trees down.

Thunderstorm Wind in MACOMB, MICHIGAN
From 04-JUL-03 12:41:00 to 04-JUL-03 12:41:00 (EST)
Location: ST CLAIR SHRS
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large tree limbs down.

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 13:13:00 to 04-JUL-03 13:13:00 (EST)
Location: PORT HURON
Magnitude: 52 EG
Property damage: 5K
Reported by: NEWSPAPER

A large tree limb, about 2 feet in circumference, crashed into a minivan, severing a power line on its way down.

Thunderstorm Wind in SAGINAW, MICHIGAN
From 04-JUL-03 11:50:00 to 04-JUL-03 11:50:00 (EST)
Location: SAGINAW
Magnitude: 55 EG
Reported by: NEWSPAPER

An estimated 50-foot tall maple tree broke a few feet above the ground and smashed into the windshield area of a vehicle, pinning the driver for more than an hour. Fallen trees or tree branches closed 27 streets in Saginaw, while another five were closed due to downed power lines.

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:07:00 to 04-JUL-03 12:07:00 (EST)
Location: LIVONIA
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

Trained spotters reported a three foot tree blown down.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:04:00 to 04-JUL-03 12:04:00 (EST)
Location: PONTIAC ARPT
Magnitude: 56 MG
Reported by: AWOS,ASOS,MESONET,ETC

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:06:00 to 04-JUL-03 12:06:00 (EST)
Location: FARMINGTON
Magnitude: 50 EG
Reported by: METEOROLOGIST(NON NWS)

A local television meteorologist reported tree limbs down.

Thunderstorm Wind in LIVINGSTON, MICHIGAN
From 04-JUL-03 11:32:00 to 04-JUL-03 11:32:00 (EST)
Location: HOWELL
Magnitude: 52 MG
Reported by: UTILITY COMPANY

Thunderstorm Wind in GENESEE, MICHIGAN
From 04-JUL-03 11:36:00 to 04-JUL-03 11:36:00 (EST)
Location: LINDEN
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported four inch diameter trees and power lines blown down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:31:00 to 04-JUL-03 11:31:00 (EST)
Location: MANCHESTER
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

Spotters reported a tree blown down on M-52.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:03:00 to 04-JUL-03 12:03:00 (EST)
Location: CLARKSTON
Magnitude: 52 EG
Reported by: NWS EMPLOYEE(OFF DUTY)

A NWS employee and trained spotter reported numerous large tree limbs down.

Thunderstorm Wind in SHIAWASSEE, MICHIGAN
From 04-JUL-03 11:15:00 to 04-JUL-03 11:15:00 (EST)
Location: PERRY
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees blown down.

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 05:30:00 to 04-JUL-03 05:30:00 (EST)
Location: ALGONAC
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

Spotters reported one tree and power pole blown down.

Thunderstorm Wind in GENESEE, MICHIGAN
From 04-JUL-03 11:35:00 to 04-JUL-03 11:35:00 (EST)
Location: LINDEN
Magnitude: 55 EG
Reported by: NWS EMPLOYEE(OFF DUTY)

A NWS employee reported two large trees blown down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:50:00 to 04-JUL-03 11:50:00 (EST)
Location: YPSILANTI
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A boat capsized on Ford Lake, but all of its passengers were rescued without incident.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:50:00 to 04-JUL-03 11:50:00 (EST)
Location: MILAN
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

Thunderstorm Wind in MONROE, MICHIGAN
From 04-JUL-03 12:04:00 to 04-JUL-03 12:04:00 (EST)
Location: DUNDEE
Magnitude: 55 EG
Reported by: LAW ENFORCEMENT

Law enforcement reported large trees and power lines blown down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:50:00 to 04-JUL-03 11:50:00 (EST)
Location: YPSILANTI
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees and power lines blown down.

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 04-JUL-03 12:51:00 to 04-JUL-03 12:51:00 (EST)
Location: SNYDERVILLE
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large limbs down.

Thunderstorm Wind in MACOMB, MICHIGAN
From 04-JUL-03 12:25:00 to 04-JUL-03 12:25:00 (EST)
Location: DISCO
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees blown down.

Thunderstorm Wind in SHIAWASSEE, MICHIGAN
From 04-JUL-03 11:21:00 to 04-JUL-03 11:21:00 (EST)
Location: OWOSSO
Magnitude: 52 EG
Reported by: LAW ENFORCEMENT

Law enforcement reported trees and wires blown down.

Thunderstorm Wind in WAYNE, MICHIGAN
From 04-JUL-03 12:04:00 to 04-JUL-03 12:04:00 (EST)
Location: WESTLAND
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees blown down.

Thunderstorm Wind in LAPEER, MICHIGAN
From 04-JUL-03 12:26:00 to 04-JUL-03 12:26:00 (EST)
Location: DRYDEN
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees blown down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:50:00 to 04-JUL-03 11:50:00 (EST)
Location: MILAN
Magnitude: 52 EG
Reported by: TRAINED SPOTTER

A trained spotter reported a tree blown onto the road.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:00:00 to 04-JUL-03 12:00:00 (EST)
Location: WHITE LAKE
Magnitude: 53 MG
Reported by: AWOS,ASOS,MESONET,ETC

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 11:54:00 to 04-JUL-03 11:54:00 (EST)
Location: WALLED LAKE
Magnitude: 50 EG
Reported by: BROADCAST MEDIA

Local media reported a tree blown onto a car.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:37:00 to 04-JUL-03 11:37:00 (EST)
Location: ANN ARBOR
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported trees blown down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:36:00 to 04-JUL-03 11:36:00 (EST)
Location: SALINE
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported large limbs down.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:40:00 to 04-JUL-03 11:40:00 (EST)
Location: WHITMORE LAKE
Magnitude: 55 EG
Property damage: 50K
Reported by: TRAINED SPOTTER

A trained spotter reported a large tree blown onto a house, trapping the residents inside.

Thunderstorm Wind in WASHTENAW, MICHIGAN
From 04-JUL-03 11:30:00 to 04-JUL-03 11:30:00 (EST)
Location: CHELSEA
Magnitude: 55 EG
Reported by: FIRE DEPT/RESCUE SQUAD

The Fire Department reported large trees and power lines down.

Thunderstorm Wind in LIVINGSTON, MICHIGAN
From 04-JUL-03 11:25:00 to 04-JUL-03 11:25:00 (EST)
Location: PINCKNEY
Magnitude: 50 EG
Reported by: GENERAL PUBLIC

The public reported numerous trees blown down.

Thunderstorm Wind in LENAWEE, MICHIGAN
From 04-JUL-03 11:37:00 to 04-JUL-03 11:37:00 (EST)
Location: ADRIAN
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

Law enforcement reported trees blown down.

Thunderstorm Wind in OAKLAND, MICHIGAN
From 04-JUL-03 12:04:00 to 04-JUL-03 12:04:00 (EST)
Location: SOUTHFIELD
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

A trained spotter reported power lines blown down.