An upper disturbance interacting with a very warm airmass and frontal boundary over southern Lake Superior helped set the stage for severe thunderstorms across portions of northern Upper Michigan during the late evening of the 15th into the morning hours of the 16th.  The hardest hit area was over the north half of Houghton County where numerous thunderstorms caused damaging winds, large hail and flash flooding from torrential downpours.  Keweenaw, Alger, Luce and northern Schoolcraft counties also observed damaging winds and/or large hail from the storms.

Flash Flood in HOUGHTON, MICHIGAN
From 16-JUL-06 04:00:00 to 16-JUL-06 09:00:00 (EST)
Location: NORTH PORTION
Reported by: TRAINED SPOTTER

Spotters measured nearly four inches of rain in Laurium with street and basement flooding reported.  2.99 inches of rain was reported at the Houghton County Airport with a washout of County Road 203 in Calumet Township.

Thunderstorm Wind in SCHOOLCRAFT, MICHIGAN
From 16-JUL-06 05:01:00 to 16-JUL-06 05:01:00 (EST)
Location: SENEY
Magnitude: 55 EG
Property damage: 3K
Reported by: GENERAL PUBLIC

Several trees down along Highway M-77 and adjoining side roads.

Hail in KEWEENAW, MICHIGAN
From 15-JUL-06 23:00:00 to 15-JUL-06 23:00:00 (EST)
Location: ISLE ROYAL NAT PARK
Magnitude: 0.88 
Reported by: PARK/FOREST SERVICE

Nickel-sized hail reported at Rock Harbor Lodge on Isle Royale.  Hail lasted approximately ten minutes.

Hail in HOUGHTON, MICHIGAN
From 16-JUL-06 04:35:00 to 16-JUL-06 04:35:00 (EST)
Location: LAURIUM
Magnitude: 0.75 
Reported by: AMATEUR RADIO

Thunderstorm Wind in HOUGHTON, MICHIGAN
From 16-JUL-06 03:00:00 to 16-JUL-06 03:00:00 (EST)
Location: FREDA
Magnitude: 50 EG
Reported by: TRAINED SPOTTER

Four-inch tree down.

Thunderstorm Wind in KEWEENAW, MICHIGAN
From 16-JUL-06 04:28:00 to 16-JUL-06 04:33:00 (EST)
Location: (P59)COPPER HARBOR
Magnitude: 55 EG
Property damage: 4K
Reported by: GENERAL PUBLIC

A dozen six to eight-inch diameter trees down between Copper Harbor and Delaware.

Heavy Rain in HOUGHTON, MICHIGAN
From 16-JUL-06 03:00:00 to 16-JUL-06 05:00:00 (EST)
Location: LAURIUM
Reported by: AMATEUR RADIO

3.67 inches of rain fell mainly between 3 and 5 am EST.

Hail in HOUGHTON, MICHIGAN
From 16-JUL-06 08:43:00 to 16-JUL-06 08:43:00 (EST)
Location: CALUMET
Magnitude: 0.75 
Reported by: TRAINED SPOTTER

Thunderstorm Wind in LUCE, MICHIGAN
From 16-JUL-06 05:18:00 to 16-JUL-06 05:18:00 (EST)
Location: NEWBERRY
Magnitude: 55 EG
Property damage: 4K
Reported by: LAW ENFORCEMENT

Numerous trees and power lines down.

Thunderstorm Wind in LUCE, MICHIGAN
From 16-JUL-06 05:25:00 to 16-JUL-06 05:30:00 (EST)
Location: NEWBERRY
Magnitude: 60 EG
Property damage: 10K
Reported by: EMERGENCY MANAGER

12-14 trees up to twelve inches in diameter down across Highway M-123 between Newberry and Tahquamenon Falls.  One tree fell on a house.

Thunderstorm Wind in HOUGHTON, MICHIGAN
From 16-JUL-06 07:28:00 to 16-JUL-06 07:28:00 (EST)
Location: (CMX)HOUGHTON-HANCOC
Magnitude: 57 MG
Reported by: AWOS,ASOS,MESONET,ETC

Gust to 69 mph also measured at the Michigan Tech Research Center.

Hail in HOUGHTON, MICHIGAN
From 16-JUL-06 04:38:00 to 16-JUL-06 04:38:00 (EST)
Location: CALUMET
Magnitude: 1.00 
Reported by: GENERAL PUBLIC

Hail fell in the Calumet/Laurium area.

Thunderstorm Wind in ALGER, MICHIGAN
From 16-JUL-06 04:44:00 to 16-JUL-06 04:44:00 (EST)
Location: GRAND MARAIS
Magnitude: 55 EG
Property damage: 4K
Reported by: LAW ENFORCEMENT

Trees down across roads and power outages.

Hail in HOUGHTON, MICHIGAN
From 16-JUL-06 05:00:00 to 16-JUL-06 05:00:00 (EST)
Location: HANCOCK
Magnitude: 2.00 
Reported by: GENERAL PUBLIC

Thunderstorm Wind in HOUGHTON, MICHIGAN
From 16-JUL-06 07:25:00 to 16-JUL-06 07:30:00 (EST)
Location: HANCOCK
Magnitude: 60 EG
Property damage: 5K
Reported by: FIRE DEPT/RESCUE SQUAD

Numerous trees down across Salo Road, Bear Lake Road and along Highway M-203 south of McLain State Park.