Hail size 1"
Fort Mc Coy Monroe County
“(ARX)”
— NOAA / SPC storm report
Hail in Sparta Apr 13, 2026
Both radar surfaces caught this storm: NEXRAD logged 0 hail signatures up to 0", and the radar-estimated size reached 1" aloft.
Largest hailstone
1"
≈ quarter · radar-estimated size aloft Homes in the hail footprint
4,986
Ground reports
3
3 hailThe 2nd most severe storm Sparta 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.
4.1 /10
- Hail size
- 25 /100
- Homes exposed
- 74 /100
- Ground truth
- 50 /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 Sparta saw the hail — from two instruments
We map this storm two ways: the NEXRAD radar signatures the storm produced overhead, and the radar-estimated size of the hail in the air. The two surfaces don’t have to match — where they diverge is where estimated size aloft ran ahead of, or behind, what the signatures caught.
NEXRAD radar signatures
NEXRAD radar signatures — the point detections the storm produced overhead. A signature is where the radar saw hail, not a confirmed stone on the ground.
Max size
0"
Detections
0
Radar-estimated hail size
Maximum hail size as estimated from radar aloft. Treat it as the storm's ceiling — the largest supportable stone — rather than a ground measurement.
Max size
1"
Where Apr 13, 2026 sits in Sparta's hail record
This was Sparta's 3rd recorded hail day, arriving 13 days after the Mar 31, 2026 storm. By severity it ranks 2nd of the 9 storms we have logged here. Radar put the day's largest stone over Sparta at 1" — radar-estimated size aloft.
The Apr 13, 2026 convective day was bigger than Sparta: the same system put hail over 467 other tracked cities, 108 of them in Wisconsin. Nearest: Tomah (12 miles northeast, up to 0.5"); Warrens (16 miles northeast, up to 1"); Mindoro (19 miles west, up to 0.5").
These maps are stills from Sparta's Apr 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.
Hail reports
3 reports Hail size 1"
6 S Four Corners Monroe County
“(ARX)”
— NOAA / SPC storm report
Hail size 1"
2 S Millston Monroe County
“(ARX)”
— 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
The storm tracked southwest at roughly 10 mph, based on the timing of ground reports.
Hail was reported over 86 minutes, from to .
Reports came from Fort Mc Coy, Four Corners, and Millston — beyond Sparta itself.
What 1" hail means for Sparta 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
$60M
Potential roof exposure — 4,986 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Illustrative jobs
25 jobs
Illustrative work
~$375K
Claims from this storm can typically be filed until around April 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Track hail over Sparta on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Sparta storm history — this Apr 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
Sparta hail history
← All hail in Sparta 9 recorded storm days in Sparta, WI
Other storms in Sparta
Jul 1, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed 
Jun 30, 2026
1.25" Signatures 1.25"
No ground reports filed 
Jun 5, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed 
May 17, 2026
Apr 23, 2026
1" Signatures 1"
No ground reports filed 
Apr 17, 2026
1" Signatures 1"
No ground reports filed 
Mar 31, 2026
1.75" Signatures 1.75" Estimated 0.5"
No ground reports filed 
Mar 30, 2026
1.75" Signatures 1.75" 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 3, 2026.