Tornado Rating unknown
3 SSW Armstrong Emmet County
“Confirmed tornado estimated via webcam. (DMX)”
— NOAA / SPC storm report
/ Storm field report · Emmet
Hail in Armstrong · May 17, 2026
NEXRAD logged 0 hail signatures up to 0"; the estimated-size surface reached 0" aloft. Open it on the live map to see the swath over the streets.
A tornado was also reported to the National Weather Service during this storm. The ground reports below show where it was filed.
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Peak hail signal 0" ≈ pea to penny · radar-estimated size aloft
Homes in the hail footprint 0
Ground reports 1 1 tornado
Radar surfaces 2 NEXRAD + estimated size
Convective day · May 17, 2026 · noon–noon UTC
Severity
The 14th most severe storm Armstrong has seen in the last 12 months
Composite score · 0.5 / 10
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
0.5 /10
- Peak hail signal
- 0 /100
- Homes exposed
- 0 /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 Armstrong saw the hail — from two instruments
May 17, 2026 · Armstrong, IA
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 Surface resolved
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.
Max size
0"
Detections
0
Radar-estimated hail size Surface resolved
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.
Max size
0"
The storm in context
Where May 17, 2026 sits in Armstrong's hail record.
This was Armstrong's 4th recorded hail day, arriving 2 days after the May 15, 2026 storm. By severity it ranks 14th of the 14 storms we have logged here. Radar put the day's largest stone over Armstrong at 0" — radar-estimated size aloft.
The May 17, 2026 convective day was bigger than Armstrong: the same system put hail over 894 other tracked cities, 139 of them in Iowa. Nearest: Swea City (11 miles east, up to 1"); Granada (12 miles northeast, up to 1.75"); Sherburn (12 miles northwest, up to 1.75").
These maps are stills. In the app this date is one of 14 Armstrong 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
1 report 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.
Tornado reports
1 reportBelow the severe threshold
What 0" hail means for Armstrong 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
Armstrong hail history
Other storms in Armstrong.
14 recorded storm days in Armstrong, IA
Estimated-size surface Storm date Armstrong / IA
Aug 9, 2026
0.5" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Aug 8, 2026
0.75" Estimated 0.75"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Aug 7, 2026
1" Estimated 1"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Jul 4, 2026
1" Signatures 1"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Jun 30, 2026
1" Signatures 1"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Jun 29, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Jun 1, 2026
1.25" Signatures 1.25" Estimated 1"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
May 26, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
May 25, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
May 18, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
May 15, 2026
2" Signatures 2" Estimated 1.25"
1 ground report Open report →
NEXRAD surface Storm date Armstrong / IA
May 14, 2026
0.75" Signatures 0.75"
No ground reports filed Open report →
Estimated-size surface Storm date Armstrong / IA
Apr 13, 2026
2.25" Signatures 2.25" Estimated 1.5"
No ground reports filed Open report →
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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 10, 2026.