Preliminary Severe Weather Roundup For The 24 Hours Ending At 1200 UTC May 12, 2025
- Bob Cox
- 7 days ago
- 4 min read
A significant severe weather event impacted multiple regions across the United States, characterized by hail and high wind events, spanning several states, with a concentration of activity in the Intermountain West (Idaho, Utah, Wyoming, Montana), the Great Plains (North Dakota, South Dakota), and isolated incidents in the Southeast (Florida, Georgia, Mississippi, South Carolina).
Overview
The severe weather was marked by:
Hail Reports: Four reported incidents, primarily in Idaho and Montana, with hail sizes ranging from 1.00 inches (quarter-sized) to 1.50 inches (ping pong ball-sized).
Wind Reports: 68 reported incidents across multiple states, with wind gusts ranging from 58 mph to 79 mph, and several reports of wind-related damage (trees down, structural damage, and vehicle incidents).
Geographic Spread: The majority of reports originated from Idaho (27), Utah (26), Wyoming (8), and Montana (7), with additional incidents in Florida, Georgia, Mississippi, South Carolina, North Dakota, and South Dakota.
Time Frame: Reports spanned from 1349 UTC (early morning local time) to 0720 UTC on May 12, 2025, with peak activity between 1800 and 0100 UTC.
Hail Reports
Summary
Total Reports: 4
Size Range: 1.00 inches (quarter-sized) to 1.50 inches (ping pong ball-sized)
Locations: Idaho (3), Montana (1)
Time Range: 1951 UTC (May 11) to 0555 UTC (May 12)
Detailed Reports
1951 UTC – 2 W Inkom, Bannock County, ID (Lat: 42.80, Lon: -112.29)
Size: 1.00 inches (quarter-sized)
Comments: Photo and video evidence submitted, showing quarter-sized hail falling west of Inkom. Time estimated via radar.
Impact: No specific damage reported, but quarter-sized hail can cause minor damage to vehicles and crops.
2101 UTC – Swan Valley, Bonneville County, ID (Lat: 43.44, Lon: -111.32)
Size: 1.00 inches (quarter-sized)
Comments: Report submitted via Facebook, with time estimated by radar.
Impact: No damage reported, but similar risks as above.
0030 UTC – Pinehurst, Shoshone County, ID (Lat: 47.53, Lon: -116.24)
Size: 1.00 inches (quarter-sized)
Comments: No additional details provided.
Impact: Likely minor, given hail size.
0555 UTC – 9 NE Weeksville, Sanders County, MT (Lat: 47.61, Lon: -114.86)
Size: 1.50 inches (ping pong ball-sized)
Comments: Reported hail ranging from pea-sized to golf ball-sized (1.50 inches). Largest hail in the dataset.
Impact: Potential for significant damage to vehicles, windows, and agricultural assets due to larger hail size.
Analysis
The hail events were relatively small in number but significant in potential impact, particularly the 1.50-inch hail in Montana, which poses a higher risk of damage.
All reports occurred in the Intermountain West, suggesting a regional focus of thunderstorm activity conducive to hail production.
The timing (late afternoon to early morning) aligns with diurnal heating and thunderstorm development.
Wind Reports
Summary
Total Reports: 68
Speed Range: 58 mph to 79 mph (highest gust at 11 SE Wapiti, WY)
Damage Reports: 13 reports of wind-related damage (trees down, structural damage, vehicle incidents)
Locations: Utah (26), Idaho (27), Wyoming (8), Montana (7), North Dakota (4), South Dakota (1), Florida (1), Georgia (1), Mississippi (1), South Carolina (1)
Time Range: 1349 UTC (May 11) to 0720 UTC (May 12)
Key Wind Gusts
Highest Gusts:
79 mph: 11 SE Wapiti, Park County, WY (2330 UTC)
79 mph: 3 N Hansen, Jerome County, ID (1945 UTC)
77 mph: 1 NNW Hettinger, Adams County, ND (0228 UTC)
75 mph (multiple locations): 6 WNW Lakeside, UT; 26 NW Knalls, UT; 6 ENE Lame Deer, MT; 10 NE Atlantic City, WY
Damage Highlights:
Trees Down: Grantsville, UT; Smithfield, UT; Victor, ID; Great Falls, MT; Starkville, MS; Ucon, ID; Rigby, ID
Structural Damage: Broxton, GA (mobile home off foundation); Starkville, MS (tree on house); Burnettown, SC (fire station doors ripped off)
Vehicle Incident: Knolls, UT (semi rollover)
Regional Breakdown
Utah (26 reports)
Peak Gust: 75 mph (6 WNW Lakeside, 2029 UTC; 26 NW Knolls, 2058 UTC)
Notable Damage:
Grantsville: Large tree down with root ball (1850 UTC).
Heber City: Intense winds breaking tree parts and damaging household items (1932 UTC).
Smithfield: Large trees down (2017 UTC).
Hotspots: Knolls (multiple gusts up to 74 mph), Lake Point, Grantsville, West Warren.
Analysis: Utah experienced widespread high winds, with Tooele and Box Elder Counties particularly affected. Mesonet stations provided precise measurements, indicating microburst activity (e.g., 72 mph microburst at West Warren, 0100 UTC).
Idaho (27 reports)
Peak Gust: 79 mph (3 N Hansen, 1945 UTC)
Notable Damage:
Victor: Several trees down in Game Creek area (2114 UTC).
Ucon: 2-3 foot diameter tree uprooted (0100 UTC).
Rigby: Several trees uprooted at Pioneer Cemetery (0100 UTC).
Hotspots: Hansen, Atomic City, Twin Falls, Victor.
Analysis: Idaho saw some of the highest wind gusts, with significant tree damage in eastern areas. The 79 mph gust in Hansen suggests a powerful thunderstorm or downburst.
Wyoming (8 reports)
Peak Gust: 79 mph (11 SE Wapiti, 2330 UTC)
Notable Damage: None reported.
Hotspots: Wapiti, Atlantic City, Farson, Moose.
Analysis: Wyoming experienced high winds in mountainous and open terrain, with gusts up to 79 mph indicating strong thunderstorm activity.
Montana (7 reports)
Peak Gust: 75 mph (6 ENE Lame Deer, 0001 UTC)
Notable Damage:
Great Falls: Large conifer tree snapped (2120 UTC).
Hotspots: Great Falls, Lame Deer.
Analysis: Montana’s reports included both high winds and damage, with the Great Falls area affected by thunderstorm-related gusts.
Southeast (FL, GA, MS, SC – 4 reports)
Notable Damage:
Hyde Park, FL: Fallen trees causing power outage (1349 UTC).
Broxton, GA: Mobile home knocked off foundation (1820 UTC).
Starkville, MS: Large elm tree on house (2150 UTC).
Burnettown, SC: Fire station bay doors ripped off (0720 UTC).
Analysis: Isolated but significant damage in the Southeast, likely from localized thunderstorms.
Great Plains (ND, SD – 5 reports)
Peak Gust: 77 mph (Hettinger, ND, 0228 UTC)
Notable Damage: None reported.
Hotspots: Hettinger, Bowman.
Analysis: High winds in North Dakota were notable, with Hettinger recording one of the highest gusts.
Damage Assessment
Tree Damage: Widespread, with reports of large trees uprooted or snapped in Utah, Idaho, Montana, and Mississippi. ThisReducers: 10,000,000
Structural Damage: Significant incidents included a mobile home off its foundation (GA), a tree on a house (MS), and fire station damage (SC).
Vehicle Incidents: A semi rollover in Knolls, UT, highlights risks to transportation.
Power Outages: Reported in Hyde Park, FL, due to fallen trees/limbs.
Meteorological Context
The severe weather on May 11, 2025, was driven by:
A strong upper-level trough/low-pressure system moving into the northwestern, contiguous U.S., and a cold front providing lift and instability, conducive to severe thunderstorms.
High wind gusts suggest downbursts or microbursts, particularly in Utah and Idaho, where mesonet stations recorded precise measurements.
Hail production indicates strong updrafts within thunderstorms, especially in Montana, where larger hail (1.50 inches) was reported.
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