Wind gust 67 mph
11 SSE Big Sandy Chouteau County
“Corrects previous tstm wnd gst report from 11 SSE Big Sandy. Montana Mesonet Big Sandy SE. (TFX)”
— NOAA / SPC storm report
Hail in Big Sandy May 13, 2026
Both radar surfaces caught this storm: NEXRAD logged 8 hail signatures up to 1.25", and the radar-estimated size reached 0.5" aloft.
Largest hailstone
1.25"
≈ half-dollar · the largest NEXRAD radar signature Homes in the hail footprint
33
Ground reports
2
2 windThe 2nd most severe storm Big Sandy has seen in the last 12 months
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
3.1 /10
- Hail size
- 31 /100
- Homes exposed
- 31 /100
- Ground truth
- 33 /100
Largest hailstone — the top predictor of roof damage.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
How Big Sandy saw the hail — from two instruments
Each storm gets two readings: the radar signatures NEXRAD recorded as the cells passed overhead, and a modeled estimate of hail size in the air. They are independent surfaces, so a mismatch between them is expected — and worth reading.
NEXRAD radar signatures
The point detections NEXRAD recorded overhead. Each signature marks where the radar saw hail aloft — it is a detection, not a stone measured on the ground.
Max size
1.25"
Detections
8
Radar-estimated hail size
Radar-estimated hail size over the swath. The model reports the biggest stone the storm could sustain in the air; what actually fell may have been smaller.
Max size
0.5"
Where May 13, 2026 sits in Big Sandy's hail record
This was Big Sandy's 1st recorded hail day — the first hail day in our records for the city. By severity it ranks 2nd of the 5 storms we have logged here. Radar put the day's largest stone over Big Sandy at 1.25" — the largest NEXRAD radar signature.
The May 13, 2026 convective day was bigger than Big Sandy: the same system put hail over 122 other tracked cities, 10 of them in Montana. Nearest: Denton (28 miles south, up to 0.75"); Geraldine (34 miles southwest, up to 1.25"); Roy (52 miles southeast, up to 1").
These maps are stills from Big Sandy's May 13, 2026 storm. In the Overview app the same surfaces are live — radar updating in real time, radar-estimated hail size as it forms, and NWS spotter reports pinned where they're filed — with a radar replay you can scrub back over any past day.
What people on the ground reported
These are storm reports filed with the National Weather Service and released through the NOAA Storm Prediction Center — public-domain observations from spotters, the public, and NWS surveys. We quote each one exactly as filed.
Wind reports
2 reports Wind gust 67 mph
11 SSE Big Sandy Chouteau County
“Montana Mesonet Big Sandy SE. (TFX)”
— NOAA / SPC storm report
Storm forensics
Read from the arrival times and locations of the NOAA ground reports,
not a radar-measured storm track.
How the storm moved
Hail was reported over 120 minutes, from to .
What 1.25" hail means for Big Sandy roofs
Quarter-size and larger hail is where asphalt shingle damage starts in earnest: bruised mats and granule loss that homeowners can't see from the ground. Most people inside the footprint won't know their roof was hit until someone inspects it.
What this storm is worth to a roofer
$396K
Potential roof exposure — 33 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage. Claims from this storm can typically be filed until around May 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Track hail over Big Sandy on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Big Sandy storm history — this May 13, 2026 storm included — sits underneath. When you're ready, draw this storm's footprint and pull highly accurate homeowner contact information for every address inside it.
Highly accurate contact information starting at $0.23 per address — every contact included. Digital leads cost $15–$40. Start with a 7-day free trial — no credit card required. See pricing
Big Sandy hail history
← All hail in Big Sandy 5 recorded storm days in Big Sandy, MT
Other storms in Big Sandy
Jun 25, 2026
1.5" Estimated 1.5"
No ground reports filed 
Jun 12, 2026
0.75" Estimated 0.75"
No ground reports filed 
May 29, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed 
May 28, 2026
1.25" Signatures 1.25" Estimated 0.75"
No ground reports filed
A storm day here is a convective day — it runs from noon to noon
UTC, so late-night hail is grouped with the afternoon storm that
spawned it rather than split across two calendar dates. Ground
reports are public-domain observations from the NOAA Storm
Prediction Center. Radar surfaces are detections and estimates,
not confirmed damage. Last updated Aug 2, 2026.