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
/ Storm field report · Chouteau
Hail in Big Sandy · May 13, 2026
NEXRAD logged 8 hail signatures up to 1.25"; the estimated-size surface reached 0.5" aloft. Open it on the live map to see the swath over the streets.
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Peak hail signal 1.25" ≈ half-dollar · the largest NEXRAD radar signature
Homes in the hail footprint 33
Ground reports 2 2 wind
Radar surfaces 2 NEXRAD + estimated size
Convective day · May 13, 2026 · noon–noon UTC
Severity
The 2nd most severe storm Big Sandy has seen in the last 12 months
Composite score · 3.1 / 10
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
3.1 /10
- Peak hail signal
- 31 /100
- Homes exposed
- 31 /100
- Ground truth
- 33 /100
Largest radar-indicated size — a signal of damage potential, not confirmation.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
Evidence / storm surfaces
How Big Sandy saw the hail — from two instruments
May 13, 2026 · Big Sandy, MT
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 Surface resolved
Radar signature field 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 Surface resolved
Estimated size field 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"
The storm in context
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: Geraldine (33 miles southwest, up to 1.25"); Denton (35 miles south, up to 0.75"); Rudyard (49 miles northwest, up to 1.25").
These maps are stills. In the app this date is one of 5 Big Sandy storm dates on a live map — both surfaces, the reports, and a replay — and the same map is where you draw the swath. This page rebuilds nightly.
Ground reports
What people on the ground reported
2 reports filed with the NWS
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
How the storm moved
Timing and place names from NOAA ground reports
Read from the arrival times and locations of the NOAA ground reports, not a radar-measured storm track.
Hail was reported over 120 minutes, from to .
Damage-capable hail signal
What 1.25" hail means for Big Sandy roofs.
Quarter-size and larger hail can bruise asphalt mats, remove granules, and dent exposed soft metal. The mapped footprint identifies an inspection priority area — it does not identify which individual roofs, if any, sustained damage.
Radar reading · not confirmed damage
Roofing exposure
What this storm is worth to a roofer.
33 homes × $12,000 avg. claim
Potential roof exposure
$396K
Potential roof exposure — 33 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Claim window
May 2028
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.
Names and phones for every home in the footprint: at most $7 on top of the $150 plan.
Big Sandy hail history
Other storms in Big Sandy.
5 recorded storm days in Big Sandy, MT
Estimated-size surface Storm date Big Sandy / MT
Jun 25, 2026
1.5" Estimated 1.5"
No ground reports filed Open report →
Estimated-size surface Storm date Big Sandy / MT
Jun 12, 2026
0.75" Estimated 0.75"
No ground reports filed Open report →
Estimated-size surface Storm date Big Sandy / MT
May 29, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Big Sandy / MT
May 28, 2026
1.25" Signatures 1.25" Estimated 0.75"
No ground reports filed Open report →
The next storm won’t wait for you.
Set your territory and alerts today. When hail hits, use Overview to choose your streets and get moving.
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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 tells you where to look. Only an inspection confirms damage at an address. Last updated Aug 2, 2026.