Severe thunderstorms broke out across Boulder, Denver, Elbert, Jefferson and Larimer Counties.  Two large and long lived tornadoes developed in Larimer County near Berthoud and near Simla in Elbert County.  The tornado that occurred along the Boulder and Larimer county line was rated an EF3 at it's highest damage point, with maximum winds estimated at 135 to 140 mph.  The path length was 6 miles long with a width of one quarter mile at times.  In Elbert County, 17 tornadoes touched down, with EF1 damage observed southwest and southeast of Simla.  Four homes suffered severe damage; two were uninhabitable.  In addition, two other homes suffered moderate damage with slight damage reported to eight other residences.  Large hail up to baseball size occurred in Elbert County, with hail up to tennis ball size observed in Boulder County.  The hail damaged cars and homes; breaking windows and windshields.

Hail in ELBERT, COLORADO
From 04-JUN-15 14:52:00 to 04-JUN-15 14:52:00 (MST-7)
Location: AGATE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Hail in LARIMER, COLORADO
From 04-JUN-15 17:08:00 to 04-JUN-15 17:08:00 (MST-7)
Location: WELLINGTON
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in DENVER, COLORADO
From 04-JUN-15 15:22:00 to 04-JUN-15 15:22:00 (MST-7)
Location: (DEN)DENVER INTL ARP
Magnitude: 0.88 
Reported by: Public

Hail in ELBERT, COLORADO
From 04-JUN-15 14:22:00 to 04-JUN-15 14:22:00 (MST-7)
Location: CEDAR PT
Magnitude: 1.50 
Reported by: Storm Chaser

Hail in ELBERT, COLORADO
From 04-JUN-15 14:42:00 to 04-JUN-15 14:42:00 (MST-7)
Location: AGATE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in ELBERT, COLORADO
From 04-JUN-15 14:46:00 to 04-JUN-15 14:46:00 (MST-7)
Location: MATHESON
Magnitude: 1.50 
Reported by: Storm Chaser

Hail in LARIMER, COLORADO
From 04-JUN-15 17:33:00 to 04-JUN-15 17:33:00 (MST-7)
Location: LOVELAND
Magnitude: 1.00 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 04-JUN-15 17:20:00 to 04-JUN-15 17:20:00 (MST-7)
Location: HARMONY
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 04-JUN-15 18:03:00 to 04-JUN-15 18:03:00 (MST-7)
Location: LYONS
Magnitude: 2.50 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 04-JUN-15 16:48:00 to 04-JUN-15 16:48:00 (MST-7)
Location: DRAKES
Magnitude: 1.00 
Reported by: CoCoRaHS

Hail in ELBERT, COLORADO
From 04-JUN-15 17:00:00 to 04-JUN-15 17:00:00 (MST-7)
Location: SIMLA
Magnitude: 2.50 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 04-JUN-15 16:51:00 to 04-JUN-15 16:51:00 (MST-7)
Location: HARMONY
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 04-JUN-15 19:30:00 to 04-JUN-15 19:30:00 (MST-7)
Location: LYONS
Magnitude: 2.50 
Reported by: CoCoRaHS

Hail in BOULDER, COLORADO
From 04-JUN-15 19:30:00 to 04-JUN-15 19:30:00 (MST-7)
Location: LONGMONT
Magnitude: 1.00 
Reported by: CoCoRaHS

Hail in LARIMER, COLORADO
From 04-JUN-15 17:46:00 to 04-JUN-15 17:46:00 (MST-7)
Location: BERTHOUD
Magnitude: 2.00 
Reported by: CoCoRaHS

Hail in JEFFERSON, COLORADO
From 04-JUN-15 20:44:00 to 04-JUN-15 20:44:00 (MST-7)
Location: ARVADA
Magnitude: 1.00 
Reported by: State Official

Hail in DENVER, COLORADO
From 04-JUN-15 22:10:00 to 04-JUN-15 22:10:00 (MST-7)
Location: DENVER
Magnitude: 1.50 
Reported by: Trained Spotter

Tornado in BOULDER, COLORADO
From 04-JUN-15 17:30:00 to 04-JUN-15 18:03:00 (MST-7)
Location: HIGHLAND
Tornado F-scale: EF3
Reported by: Trained Spotter

The tornado first touched about 3 miles south of Berthoud, and then tracked to the west/northwest and lifted about 6 miles southwest of Berthoud. The majority of the damage was EF1, with some areas of EF2, and a few small areas of EF3.  At least 25 homes between Longmont and Berthoud were damaged; three of them destroyed.  No injuries were reported as the winds tore apart homes and rolled vehicles.

Hail in ELBERT, COLORADO
From 04-JUN-15 17:05:00 to 04-JUN-15 17:05:00 (MST-7)
Location: SIMLA
Magnitude: 2.75 
Reported by: Amateur Radio

Hail in ELBERT, COLORADO
From 04-JUN-15 16:59:00 to 04-JUN-15 16:59:00 (MST-7)
Location: SIMLA
Magnitude: 2.50 
Reported by: Trained Spotter

Hail in JEFFERSON, COLORADO
From 04-JUN-15 17:35:00 to 04-JUN-15 17:35:00 (MST-7)
Location: ARVADA
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in JEFFERSON, COLORADO
From 04-JUN-15 20:30:00 to 04-JUN-15 20:30:00 (MST-7)
Location: ARVADA
Magnitude: 1.00 
Reported by: Trained Spotter

Flash Flood in LARIMER, COLORADO
From 04-JUN-15 20:15:00 to 05-JUN-15 03:00:00 (MST-7)
Location: BERTHOUD
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 10.00K
Reported by: Local Official

Significant flooding was observed along the Larimer/Boulder county line.  Numerous roads were closed due to flash flooding.

Thunderstorm Wind in ELBERT, COLORADO
From 04-JUN-15 12:19:00 to 04-JUN-15 12:19:00 (MST-7)
Location: SIMLA
Magnitude: 70.00 EG
Reported by: NWS Storm Survey

A home sustained some roof and window damage and an RV was blown on its side.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:21:00 to 04-JUN-15 17:33:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

Two tornadoes touched down in close proximity to one another, one of which was anticyclonic.  Both occurred in open country so no damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:15:00 to 04-JUN-15 17:19:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down in open country.  No damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:26:00 to 04-JUN-15 17:30:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A well defined tornado touched down in open country.  No damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:32:00 to 04-JUN-15 17:33:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down in open country.  No damage was observed.

Tornado in LARIMER, COLORADO
From 04-JUN-15 18:03:00 to 04-JUN-15 18:08:00 (MST-7)
Location: BERTHOUD
Tornado F-scale: EF3
Reported by: Trained Spotter

The tornado contiinued its track into Larimer County.  At least 25 homes between Longmont and Berthoud were damaged; three of them destroyed.  No injuries were reported as the winds tore apart homes and rolled vehicles.

Hail in LARIMER, COLORADO
From 04-JUN-15 16:58:00 to 04-JUN-15 16:58:00 (MST-7)
Location: LOVELAND
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in DENVER, COLORADO
From 04-JUN-15 22:04:00 to 04-JUN-15 22:04:00 (MST-7)
Location: DENVER
Magnitude: 1.00 
Reported by: Trained Spotter

Tornado in ELBERT, COLORADO
From 04-JUN-15 15:38:00 to 04-JUN-15 15:39:00 (MST-7)
Location: FONDIS
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down briefly but did no damage.

Hail in LARIMER, COLORADO
From 04-JUN-15 16:57:00 to 04-JUN-15 16:57:00 (MST-7)
Location: LAPORTE
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in LARIMER, COLORADO
From 04-JUN-15 16:52:00 to 04-JUN-15 16:52:00 (MST-7)
Location: FT COLLINS
Magnitude: 1.25 
Reported by: Amateur Radio

Hail in JEFFERSON, COLORADO
From 04-JUN-15 18:00:00 to 04-JUN-15 18:00:00 (MST-7)
Location: GOLDEN
Magnitude: 0.88 
Reported by: CoCoRaHS

Hail in DENVER, COLORADO
From 04-JUN-15 22:23:00 to 04-JUN-15 22:23:00 (MST-7)
Location: DENVER
Magnitude: 1.00 
Reported by: Trained Spotter

Tornado in ELBERT, COLORADO
From 04-JUN-15 16:53:00 to 04-JUN-15 16:54:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF1
Reported by: Storm Chaser

A tornado touched down and destroyed a pole barn.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:34:00 to 04-JUN-15 17:37:00 (MST-7)
Location: MATHESON
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A well defined tornado touched down in open country.  No damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:36:00 to 04-JUN-15 17:39:00 (MST-7)
Location: KUTCH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

An anticyclonic tornado touched down in open country.  No damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:41:00 to 04-JUN-15 17:44:00 (MST-7)
Location: KUTCH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down in open country.  No damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 16:12:00 to 04-JUN-15 16:16:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down for a short time but no damage was observed.

Tornado in ELBERT, COLORADO
From 04-JUN-15 16:20:00 to 04-JUN-15 16:23:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down briefly but did no damage.

Hail in ELBERT, COLORADO
From 04-JUN-15 16:40:00 to 04-JUN-15 16:40:00 (MST-7)
Location: SIMLA
Magnitude: 2.75 
Reported by: Broadcast Media

Hail in BOULDER, COLORADO
From 04-JUN-15 19:10:00 to 04-JUN-15 19:10:00 (MST-7)
Location: LONGMONT
Magnitude: 1.25 
Reported by: Trained Spotter

Hail in BOULDER, COLORADO
From 04-JUN-15 18:13:00 to 04-JUN-15 18:13:00 (MST-7)
Location: LYONS
Magnitude: 2.00 
Reported by: CoCoRaHS

Hail in DENVER, COLORADO
From 04-JUN-15 22:19:00 to 04-JUN-15 22:19:00 (MST-7)
Location: (DEN)DENVER INTL ARP
Magnitude: 1.50 
Reported by: Trained Spotter

Tornado in ELBERT, COLORADO
From 04-JUN-15 16:30:00 to 04-JUN-15 16:40:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF1
Reported by: Storm Chaser

A well defined tornado touched down and produced some damage. Near U.S. Highway 24, tree branches 1 to 3 inches diameter were snapped.  The tornado then strengthened to a magnitude EF1 tornado as it tracked south of the highway.  Several hardwood trees were snapped near their trunks.  A fuel tank was thrown and a barn damaged.  In addition, a road sign was flattened at its base.

Hail in DENVER, COLORADO
From 04-JUN-15 22:15:00 to 04-JUN-15 22:15:00 (MST-7)
Location: DENVER
Magnitude: 1.00 
Reported by: Trained Spotter

Hail in DENVER, COLORADO
From 04-JUN-15 22:11:00 to 04-JUN-15 22:11:00 (MST-7)
Location: DENVER
Magnitude: 0.88 
Reported by: Trained Spotter

Tornado in ELBERT, COLORADO
From 04-JUN-15 18:10:00 to 04-JUN-15 18:14:00 (MST-7)
Location: KUTCH
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

The last in a series of well defined tornadoes touched down in open country.  No damage was observed.

Flash Flood in BOULDER, COLORADO
From 04-JUN-15 20:22:00 to 05-JUN-15 03:00:00 (MST-7)
Location: LYONS
Flood cause: Heavy Rain
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain, with radar estimates up to 8 inches northwest of Longmont, forced numerous road closures.  The heaviest rainfall occurred from around Lyons eastward along the Little Thompson River Basin.

Tornado in ELBERT, COLORADO
From 04-JUN-15 16:38:00 to 04-JUN-15 16:39:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado with an anticyclonic rotation touched down briefly but did no damage.

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:05:00 to 04-JUN-15 17:09:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Storm Chaser

A tornado touched down in open country.  No damage was observed.

Hail in DENVER, COLORADO
From 04-JUN-15 22:10:00 to 04-JUN-15 22:10:00 (MST-7)
Location: DENVER
Magnitude: 1.25 
Reported by: CoCoRaHS

Tornado in ELBERT, COLORADO
From 04-JUN-15 17:17:00 to 04-JUN-15 17:24:00 (MST-7)
Location: SIMLA
Tornado F-scale: EF0
Crop damage: 0.00K
Reported by: Storm Chaser

A well defined tornado touched down and produced some property damage at a farmstead.  The home, barn and nearby outbuildings sustained damage.  A power pole was also snapped about 5 feet above the ground.