Thunderstorms develop across western and southwest Montana, and continue to become more widespread. Daytime heating provides moderate instability for convective initiation. Inverted-v type soundings, characterized by a deep and dry boundary layer, support DCAPE values near 1000 J/kg. Thus, damaging wind gusts are the primary hazard associated with stronger thunderstorms. Shear profiles strengthen and may be enough to support a few supercell thunderstorms capable of producing locally heavy
rain, small hail, and with marginal support for an isolated larger hail event to the size of quarters. The severe storm potential peaks by early evening, although showers and thunderstorms continue to spread across the region overnight. This activity is associated with a passing upper level shortwave trough and its associated surface front.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 18:54:00 to 24-JUN-20 18:54:00 (MST-7)
Location: FLOWEREE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Corrected time. Reports strong winds brought rain into attic of house and knocked down trees. Also, reports a pile of peas sized hail. Wind speed and gust estimate not reported.

Hail in TETON, MONTANA
From 24-JUN-20 18:36:00 to 24-JUN-20 18:36:00 (MST-7)
Location: POWER
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A lot of quarter to ping pong sized hail. Also, reports wind shredded pine trees and a lot of branches down.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 19:06:00 to 24-JUN-20 19:06:00 (MST-7)
Location: FLOWEREE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Relayed report from trained spotter of trees stripped and power outage from thunderstorm winds gusts. Wind speed and gust estimate not reported.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 19:12:00 to 24-JUN-20 19:12:00 (MST-7)
Location: CARTER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports some tree branch damage from strong winds. Small hail also observed along with some water on road. Wind speed and gust estimate not reported.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 19:37:00 to 24-JUN-20 19:37:00 (MST-7)
Location: FLOWEREE
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports strong winds brought rain into attic of house and knocked down trees. Also, reports a pile of pea sized hail. Wind speed and gust estimate not reported.

Thunderstorm Wind in MADISON, MONTANA
From 24-JUN-20 16:55:00 to 24-JUN-20 16:55:00 (MST-7)
Location: TWIN BRIDGES ARPT
Magnitude: 64.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Data from awos station K7S1 Twin Bridges.

Thunderstorm Wind in LEWIS AND CLARK, MONTANA
From 24-JUN-20 16:58:00 to 24-JUN-20 16:58:00 (MST-7)
Location: SIEBEN
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Report from 8 SSW Wolf Creek. Mesonet station  301005 Sieben.

Thunderstorm Wind in MADISON, MONTANA
From 24-JUN-20 17:50:00 to 24-JUN-20 17:50:00 (MST-7)
Location: ENNIS
Magnitude: 54.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Mesonet station ENNM8 Ennis raws. Time estimated based on radar.

Thunderstorm Wind in TETON, MONTANA
From 24-JUN-20 18:04:00 to 24-JUN-20 18:04:00 (MST-7)
Location: CLEIV
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public report.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 19:00:00 to 24-JUN-20 19:00:00 (MST-7)
Location: CARTER
Magnitude: 52.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reports estimated wind gusts near 60 mph in Carter.

Thunderstorm Wind in CHOUTEAU, MONTANA
From 24-JUN-20 19:06:00 to 24-JUN-20 19:06:00 (MST-7)
Location: FLOWEREE
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind and rain reduced visibility to less than 100 feet. Reports 0.80 inches of rain in 15 minutes. Also, reports pea sized hail.