“Mesonet site: UP830 reported at 62.0 mph gust. (GLD)”
— NOAA / SPC storm report
Hail in Grinnell · Aug 13, 2026
NEXRAD logged 0 hail signatures up to 0"; the estimated-size surface reached 1" aloft. Open it on the live map to see the swath over the streets.
Convective day · Aug 13, 2026 · noon–noon UTC
Severity
The 3rd most severe storm Grinnell has seen in the last 12 months
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
- Peak hail signal
- 25 /100
- Homes exposed
- 59 /100
- Ground truth
- 17 /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 Grinnell 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.
Radar signature field 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.
Estimated size field Maximum hail size as estimated from radar aloft. Treat it as the storm's ceiling — the largest supportable stone — rather than a ground measurement.
The storm in context
Where Aug 13, 2026 sits in Grinnell's hail record.
This was Grinnell's 8th recorded hail day, arriving 35 days after the Jul 9, 2026 storm. By severity it ranks 3rd of the 9 storms we have logged here. Radar put the day's largest stone over Grinnell at 1" — radar-estimated size aloft.
The Aug 13, 2026 convective day was bigger than Grinnell: the same system put hail over 437 other tracked cities, 62 of them in Kansas. Nearest: Gove (13 miles southeast, up to 1.75"); Grainfield (13 miles northeast, up to 1"); Oakley (15 miles northwest, up to 1.25").
These maps are stills. In the app this date is one of 9 Grinnell 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
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
1 reportDamage-capable hail signal
What 1" hail means for Grinnell 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.
Potential roof exposure
$11M
Potential roof exposure — 875 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
- Illustrative jobs
- 4 jobs
- Illustrative work
- ~$60K
Close just 0.5% of the 875 homes in this footprint at the average $15,000 roof job. Illustrative math, not a projection — your results depend on your outreach and how the market responds.
Claim window
August 2028
Claims from this storm can typically be filed until around August 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 $184 on top of the $150 plan.
Grinnell hail history
Other storms in Grinnell.
Estimated-size surface Aug 19, 2026
1"
Estimated-size surface Jul 9, 2026
1"
Estimated-size surface Jul 3, 2026
1"
Estimated-size surface Jun 30, 2026
1"
Estimated-size surface Jun 20, 2026
2.5"
Estimated-size surface Jun 1, 2026
1"
Estimated-size surface Apr 26, 2026
0.5"
Estimated-size surface Apr 11, 2026
0.75"Take your next area into the field.
See the hail, review your recommendations, and canvass with Overview on iPhone.
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