A weak cold front moved through southeast Michigan on July 13th, ushering in slightly cooler and less humid air.  However, thanks to a strong upper level disturbance, temperatures aloft cooled off much more quickly.  This cold air aloft, combined with ample heating from sunshine on the 14th, resulted in an unstable atmosphere.  Thunderstorms developed explosively early in the afternoon, and many became severe.Large hail was the predominant severe weather type on this day.  The strongest storm of the day was a supercell that moved south along the Lake Huron lake breeze boundary.  This storm developed near Port Sanilac, and moved through Port Huron before exiting the area near Algonac.  Golfball sized hail was reported near Lexington and Port Huron with this storm.  Hailstones as large as baseballs crashed down on Algonac, damaging cars and roofs, ripping gutters off of homes, denting air conditioning units, and breaking windows.  The force of impact when these hailstones landed in Algonac canals propelled water 5 feet into the air.  Several other storms produced large hail, though none as large as in Algonac.  Golfball sized hail also fell in metro Flint, as well as near Hartland.  Dime, nickel, and quarter sized hail was quite common.Wind damage was not as widespread, though a few very strong gusts occurred.  Numerous trees were downed between Gratiot and Court Streets in Saginaw, damaging vehicles, fences, and outbuildings.  A few trees were also downed by severe thunderstorm winds in Millington and Gagetown.  Near the end of the episode, a severe thunderstorm produced estimated 80 mph winds near Gaines.  Several agricultural outbuildings were heavily damaged or destroyed.

Hail in LAPEER, MICHIGAN
From 14-JUL-00 14:43:00 to 14-JUL-00 14:43:00 (EST)
Location: IMLAY CITY
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in GENESEE, MICHIGAN
From 14-JUL-00 12:25:00 to 14-JUL-00 12:36:00 (EST)
Location: FLINT
Magnitude: 1.75 
Reported by: GENERAL PUBLIC

Hail in LAPEER, MICHIGAN
From 14-JUL-00 12:34:00 to 14-JUL-00 12:34:00 (EST)
Location: LAPEER
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Hail in GENESEE, MICHIGAN
From 14-JUL-00 12:45:00 to 14-JUL-00 12:45:00 (EST)
Location: GOODRICH
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Thunderstorm Wind in GENESEE, MICHIGAN
From 14-JUL-00 13:35:00 to 14-JUL-00 13:35:00 (EST)
Location: FENTON
Magnitude: 52 E
Reported by: TRAINED SPOTTER

Thunderstorm Wind in SAGINAW, MICHIGAN
From 14-JUL-00 13:00:00 to 14-JUL-00 13:00:00 (EST)
Location: SAGINAW
Magnitude: 55 E
Property damage: 60K
Reported by: TRAINED SPOTTER

Hail in LENAWEE, MICHIGAN
From 14-JUL-00 15:00:00 to 14-JUL-00 15:00:00 (EST)
Location: CLINTON
Magnitude: 1.00 
Reported by: GENERAL PUBLIC

Hail in GENESEE, MICHIGAN
From 14-JUL-00 17:07:00 to 14-JUL-00 17:07:00 (EST)
Location: ARGENTINE
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in TUSCOLA, MICHIGAN
From 14-JUL-00 15:40:00 to 14-JUL-00 15:40:00 (EST)
Location: CASS CITY
Magnitude: 50 E
Property damage: 3K
Reported by: LAW ENFORCEMENT

Hail in LIVINGSTON, MICHIGAN
From 14-JUL-00 15:15:00 to 14-JUL-00 15:15:00 (EST)
Location: HARTLAND
Magnitude: 1.75 
Reported by: TRAINED SPOTTER

Hail in OAKLAND, MICHIGAN
From 14-JUL-00 13:05:00 to 14-JUL-00 13:05:00 (EST)
Location: HOLLY
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Hail in ST. CLAIR, MICHIGAN
From 14-JUL-00 13:43:00 to 14-JUL-00 13:43:00 (EST)
Location: MARINE CITY
Magnitude: 1.25 
Reported by: TRAINED SPOTTER

Hail in SANILAC, MICHIGAN
From 14-JUL-00 12:17:00 to 14-JUL-00 12:29:00 (EST)
Location: APPLEGATE
Magnitude: 1.75 
Reported by: LAW ENFORCEMENT

Hail in WASHTENAW, MICHIGAN
From 14-JUL-00 14:45:00 to 14-JUL-00 14:45:00 (EST)
Location: ANN ARBOR
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in ST. CLAIR, MICHIGAN
From 14-JUL-00 13:43:00 to 14-JUL-00 13:43:00 (EST)
Location: MARINE CITY
Magnitude: 52 E
Reported by: TRAINED SPOTTER

Hail in OAKLAND, MICHIGAN
From 14-JUL-00 15:45:00 to 14-JUL-00 15:45:00 (EST)
Location: SOUTH LYON
Magnitude: 1.00 
Reported by: GENERAL PUBLIC

Thunderstorm Wind in TUSCOLA, MICHIGAN
From 14-JUL-00 14:54:00 to 14-JUL-00 14:54:00 (EST)
Location: MILLINGTON
Magnitude: 54 E
Property damage: 10K
Reported by: LAW ENFORCEMENT

Thunderstorm Wind in GENESEE, MICHIGAN
From 14-JUL-00 17:00:00 to 14-JUL-00 17:00:00 (EST)
Location: GAINES
Magnitude: 69 E
Property damage: 40K
Reported by: NWS STORM SURVEY

Hail in ST. CLAIR, MICHIGAN
From 14-JUL-00 14:00:00 to 14-JUL-00 14:00:00 (EST)
Location: ALGONAC
Magnitude: 2.75 
Property damage: 125K
Reported by: BROADCAST MEDIA

Hail in GENESEE, MICHIGAN
From 14-JUL-00 16:53:00 to 14-JUL-00 16:55:00 (EST)
Location: GRAND BLANC
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in WASHTENAW, MICHIGAN
From 14-JUL-00 14:54:00 to 14-JUL-00 14:54:00 (EST)
Location: WHITTAKER
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in ST. CLAIR, MICHIGAN
From 14-JUL-00 13:05:00 to 14-JUL-00 13:08:00 (EST)
Location: PORT HURON
Magnitude: 1.75 
Reported by: LAW ENFORCEMENT

Hail in OAKLAND, MICHIGAN
From 14-JUL-00 14:45:00 to 14-JUL-00 14:45:00 (EST)
Location: PONTIAC
Magnitude: 0.75 
Reported by: LAW ENFORCEMENT

Hail in HURON, MICHIGAN
From 14-JUL-00 15:30:00 to 14-JUL-00 15:30:00 (EST)
Location: OWENDALE
Magnitude: 0.75 
Reported by: GENERAL PUBLIC

Hail in OAKLAND, MICHIGAN
From 14-JUL-00 14:08:00 to 14-JUL-00 14:08:00 (EST)
Location: PONTIAC
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in LIVINGSTON, MICHIGAN
From 14-JUL-00 15:25:00 to 14-JUL-00 15:30:00 (EST)
Location: HARTLAND
Magnitude: 1.50 
Reported by: GENERAL PUBLIC

Hail in SHIAWASSEE, MICHIGAN
From 14-JUL-00 16:35:00 to 14-JUL-00 16:35:00 (EST)
Location: JUDDVILLE
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Hail in SHIAWASSEE, MICHIGAN
From 14-JUL-00 13:00:00 to 14-JUL-00 13:00:00 (EST)
Location: PERRY
Magnitude: 1.00 
Reported by: LAW ENFORCEMENT

Hail in GENESEE, MICHIGAN
From 14-JUL-00 14:13:00 to 14-JUL-00 14:13:00 (EST)
Location: FLINT
Magnitude: 1.00 
Reported by: TRAINED SPOTTER