Hail in Knoxville · Aug 13, 2026
The estimated-size surface reached 0.5" aloft; NEXRAD logged no point detections over Knoxville that day. Open it on the live map to see the swath over the streets.
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Convective day · Aug 13, 2026 · noon–noon UTC
Severity
The 9th most severe storm Knoxville 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
- 13 /100
- Homes exposed
- 29 /100
- Ground truth
- 0 /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 Knoxville 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.
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.
Only the radar-estimated size surface resolved for Aug 13, 2026 — this storm produced no NEXRAD point detections over Knoxville, so there is one map to show, not two.
The storm in context
Where Aug 13, 2026 sits in Knoxville's hail record.
This was Knoxville's 10th recorded hail day, arriving 1 day after the Aug 12, 2026 storm. By severity it ranks 9th of the 11 storms we have logged here. Radar put the day's largest stone over Knoxville at 0.5" — radar-estimated size aloft.
The Aug 13, 2026 convective day was bigger than Knoxville: the same system put hail over 437 other tracked cities, 46 of them in Iowa. Nearest: Otley (14 miles north, up to 0.5"); Monroe (16 miles northwest, up to 0.5"); Eddyville (21 miles southeast, up to 0.5").
These maps are stills. In the app this date is one of 11 Knoxville 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.
For this storm over Knoxville, the NWS report log is empty — a common outcome, since ground reports only happen when someone witnesses the hail and takes the time to call it in. The detection record for the date lives in the radar maps above.
Below the severe threshold
What 0.5" hail means for Knoxville roofs.
Radar signals under three-quarters of an inch stay below the National Weather Service severe threshold and generally indicate lower roof risk. Older or already-worn materials can still show effects, but radar alone cannot determine whether a specific roof was damaged.
Radar reading · not confirmed damage
Roofing exposure
What this storm is worth to a roofer.
Potential roof exposure
$324K
Potential roof exposure — 27 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
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 $6 on top of the $150 plan.
Knoxville hail history
Other storms in Knoxville.
Sep 8, 2026
0.5"
Estimated-size surface Aug 12, 2026
0.5"
Estimated-size surface Jul 20, 2026
1.75"
Estimated-size surface Jul 3, 2026
1.75"
Estimated-size surface Jun 11, 2026
2.75"
Estimated-size surface Jun 10, 2026
0.5"
Estimated-size surface Jun 5, 2026
2.5"
Estimated-size surface May 18, 2026
0.5"
Estimated-size surface May 15, 2026
1"
Estimated-size surface Apr 17, 2026
1.5"Take your next area into the field.
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