Tornado Rating unknown
5 ENE Avalon Rock County
“Snapped and uprooted trees... damage to houses... and sheet metal wrapped around trees near Emerald Grove. Time estimated from radar. (MKX)”
— NOAA / SPC storm report
Hail in Darien Apr 17, 2026
Both radar surfaces caught this storm: NEXRAD logged 24 hail signatures up to 2", and the radar-estimated size reached 0.75" aloft. At 2" — tennis ball — this is severe, roof-replacing hail: close to every roof inside the footprint becomes a claim candidate.
A tornado was also reported to the National Weather Service during this storm — see the ground reports below.
Largest hailstone
2"
≈ tennis ball · the largest NEXRAD radar signature Homes in the hail footprint
808
Ground reports
3
3 tornadoThe most severe storm Darien 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.
6.0 /10
- Hail size
- 50 /100
- Homes exposed
- 58 /100
- Ground truth
- 100 /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 Darien saw the hail — from two instruments
The maps here read the same storm from two angles — point detections from NEXRAD, and modeled hail size aloft. Where the two disagree is informative: it marks where estimated size outran the signatures, or trailed them.
NEXRAD radar signatures
Where NEXRAD flagged hail as the storm passed — point signatures from the radar, which indicate hail overhead rather than confirm what landed.
Max size
2"
Detections
24
Radar-estimated hail size
The modeled maximum hail size across the swath, derived from radar aloft — the largest stone the storm could have supported, which is not necessarily what reached the ground.
Max size
0.75"
Where Apr 17, 2026 sits in Darien's hail record
This was Darien's 2nd recorded hail day, arriving 17 days after the Mar 31, 2026 storm. By severity it ranks 1st of the 4 storms we have logged here. Radar put the day's largest stone over Darien at 2" — the largest NEXRAD radar signature.
The Apr 17, 2026 convective day was bigger than Darien: the same system put hail over 1,016 other tracked cities, 178 of them in Wisconsin. Nearest: Delavan (5 miles east, up to 2.75"); Avalon (9 miles northwest, up to 2"); Sharon (9 miles southwest, up to 1").
These maps are stills from Darien's Apr 17, 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.
Tornado reports
3 reports Tornado Rating unknown
3 WNW Delavan Walworth County
“NWS Damage Survey concludes an EF-1 tornado occurred with estimated peak winds of 100 mph. The tornado started near Turtle Creek by Klug Road... lifting northeastward t (MKX)”
— NOAA / SPC storm report
Tornado Rating unknown
3 NNW Darien Walworth County
“NWS Storm Survey concludes an EF-1 tornado occurred with estimated peak winds of 100 mph. The tornado started just north of School Section Road... traveled along State (MKX)”
— 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 east at roughly 5 mph, based on the timing of ground reports.
Hail was reported over 37 minutes, from to .
Reports came from Avalon and Delavan — beyond Darien itself.
What 2" hail means for Darien roofs
Two-inch-plus hail punctures shingles, breaks skylights and windows, and dents anything soft. In the core of a footprint like this, close to every roof is a candidate for an insurance claim. Speed decides who writes those jobs.
What this storm is worth to a roofer
$9.7M
Potential roof exposure — 808 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Illustrative jobs
4 jobs
Illustrative work
~$60K
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 Darien on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Darien storm history — this Apr 17, 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
Darien hail history
← All hail in Darien 4 recorded storm days in Darien, WI
Other storms in Darien
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.