The passage of a cold front through a very warm and unstable air mass generated scattered severe thunderstorms across portions of west and central Upper Michigan on the afternoon of the 21st.

Hail in MARQUETTE, MICHIGAN
From 21-AUG-13 15:00:00 to 21-AUG-13 15:10:00 (EST-5)
Location: SAND RIVER
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter to dime-sized hail fell for about five to ten minutes.

Thunderstorm Wind in ONTONAGON, MICHIGAN
From 21-AUG-13 15:25:00 to 21-AUG-13 15:29:00 (EST-5)
Location: BERGLAND
Magnitude: 55.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: NWS Employee

Several trees were downed, and one of the trees was estimated to have a 12-15 inch diameter.  Time of the event was estimated from radar.

Hail in ALGER, MICHIGAN
From 21-AUG-13 15:35:00 to 21-AUG-13 15:38:00 (EST-5)
Location: AU TRAIN
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny-sized hail was observed near Au Train.

Hail in MARQUETTE, MICHIGAN
From 21-AUG-13 16:25:00 to 21-AUG-13 16:29:00 (EST-5)
Location: SKANDIA
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny-sized hail was observed near Skandia.

Hail in IRON, MICHIGAN
From 21-AUG-13 15:31:00 to 21-AUG-13 15:36:00 (CST-6)
Location: SCOTT LAKE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Some quarter-sized hail was reported with a lot of pea to dime-sized hail.

Hail in ALGER, MICHIGAN
From 21-AUG-13 16:40:00 to 21-AUG-13 16:45:00 (EST-5)
Location: CHATHAM
Magnitude: 1.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Hail report near Chatham was received via WLUC-TV Facebook page.  Time of report was estimated from radar.

Hail in ALGER, MICHIGAN
From 21-AUG-13 16:40:00 to 21-AUG-13 16:45:00 (EST-5)
Location: CHATHAM
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Penny-sized hail was reported near Chatham.

Hail in IRON, MICHIGAN
From 21-AUG-13 16:02:00 to 21-AUG-13 16:07:00 (CST-6)
Location: ROGERS
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny-sized hail was reported northeast of Iron River.

Hail in ALGER, MICHIGAN
From 21-AUG-13 17:05:00 to 21-AUG-13 17:10:00 (EST-5)
Location: TRENARY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There were several reports of dime to quarter-sized hail in Trenary.

Hail in ALGER, MICHIGAN
From 21-AUG-13 17:05:00 to 21-AUG-13 17:28:00 (EST-5)
Location: WINTERS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter near Round Lake reported that two different storms dropped quarter-sized hail.  The first storm passed through around 17:05 EST and the second went through around 17:23 EST.

Hail in DICKINSON, MICHIGAN
From 21-AUG-13 16:46:00 to 21-AUG-13 16:50:00 (CST-6)
Location: ANTOINE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Penny-sized hail was reported near Iron Mountain.

Hail in MARQUETTE, MICHIGAN
From 21-AUG-13 14:54:00 to 21-AUG-13 14:59:00 (EST-5)
Location: TROWBRIDGE PARK
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Dime-sized hail with a few up to penny-sized hailstones reported near Wright Street and Highway US-41.

Hail in ONTONAGON, MICHIGAN
From 21-AUG-13 15:30:00 to 21-AUG-13 15:34:00 (EST-5)
Location: BERGLAND
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Gusty winds were also observed which knocked down some small limbs.

Hail in ALGER, MICHIGAN
From 21-AUG-13 16:03:00 to 21-AUG-13 16:08:00 (EST-5)
Location: GRAND MARAIS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mostly quarter-sized hail was observed in Grand Marais.  There were a few flat stones approaching the diameter of a golf ball.

Hail in ALGER, MICHIGAN
From 21-AUG-13 16:40:00 to 21-AUG-13 16:45:00 (EST-5)
Location: EBEN JCT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Quarter-sized hail was reported at Eben Junction.