/ Storm field report · Pottawattamie

Hail in Griswold · Sep 14, 2026

Hit 3 days ago

The estimated-size surface reached 0.75" aloft; NEXRAD logged no point detections over Griswold that day. Open it on the live map to see the swath over the streets.

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Peak hail signal 0.75" ≈ penny to nickel · radar-estimated size aloft
Homes in the hail footprint 1,052
Ground reports 0 none filed
Radar surfaces 1 Estimated size only

Convective day · Sep 14, 2026 · noon–noon UTC

Severity

The 11th most severe storm Griswold has seen in the last 12 months

Composite score · 2.6 / 10
Storm severity score

Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.

2.6 /10
Peak hail signal
19 /100

Largest radar-indicated size — a signal of damage potential, not confirmation.

Homes exposed
60 /100

How many homes sit inside the storm's footprint.

Ground truth
0 /100

Independent storm reports filed with the NWS.

Evidence / storm surfaces

How Griswold saw the hail — from two instruments

Sep 14, 2026 · Griswold, 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.

Radar-estimated hail size Surface resolved
Map image is still rendering for this surface.

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 0.75"

Only the radar-estimated size surface resolved for Sep 14, 2026 — this storm produced no NEXRAD point detections over Griswold, so there is one map to show, not two.

The storm in context

Where Sep 14, 2026 sits in Griswold's hail record.

This was Griswold's 15th recorded hail day, arriving 8 days after the Sep 6, 2026 storm. By severity it ranks 11th of the 15 storms we have logged here. Radar put the day's largest stone over Griswold at 0.75" — radar-estimated size aloft.

The Sep 14, 2026 convective day was bigger than Griswold: the same system put hail over 110 other tracked cities, 24 of them in Iowa. Nearest: Emerson (10 miles southwest, up to 0.5"); Mc Clelland (24 miles west, up to 0.5"); Council Bluffs (29 miles west, up to 0.5").

These maps are stills. In the app this date is one of 15 Griswold 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

No reports 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.

Nobody on the ground filed a report over Griswold for this date, which says more about who was watching than about the storm: spotter reports only exist where there is an observer. The radar surfaces above carry the evidence for this one.

Near the severe threshold

What 0.75" hail means for Griswold roofs.

A signal this size sits near the National Weather Service severe threshold. Aging shingles and soft metals such as vents, flashing, and gutters may be more vulnerable; roof age, wind, and material condition all matter, and only an inspection can confirm damage.

Radar reading · not confirmed damage

Roofing exposure

What this storm is worth to a roofer.

1,052 homes × $12,000 avg. claim

Potential roof exposure

$13M

Potential roof exposure — 1,052 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.

Illustrative jobs
5 jobs
Illustrative work
~$75K

Close just 0.5% of the 1,052 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

September 2028

Claims from this storm can typically be filed until around September 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 $221 on top of the $150 plan.

Griswold hail history

15 recorded storm days in Griswold, IA
Radar-estimated hail-size map of the storm over Griswold, IA on Sep 6, 2026 Estimated-size surface
Storm date Griswold / IA

Sep 6, 2026

1"
Estimated 1"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Aug 8, 2026 Estimated-size surface
Storm date Griswold / IA

Aug 8, 2026

0.75"
Estimated 0.75"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Aug 4, 2026 Estimated-size surface
Storm date Griswold / IA

Aug 4, 2026

1"
Estimated 1"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Jul 20, 2026 Estimated-size surface
Storm date Griswold / IA

Jul 20, 2026

0.75"
Estimated 0.75"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Jun 6, 2026 Estimated-size surface
Storm date Griswold / IA

Jun 6, 2026

2"
Signatures 2" Estimated 1"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Jun 5, 2026 Estimated-size surface
Storm date Griswold / IA

Jun 5, 2026

1.75"
Signatures 1.75" Estimated 1.25"
2 ground reports Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on May 31, 2026 Estimated-size surface
Storm date Griswold / IA

May 31, 2026

1.75"
Signatures 1.75" Estimated 1.25"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on May 18, 2026 Estimated-size surface
Storm date Griswold / IA

May 18, 2026

1.5"
Signatures 1.5" Estimated 0.5"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on May 17, 2026 Estimated-size surface
Storm date Griswold / IA

May 17, 2026

1"
Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on May 16, 2026 Estimated-size surface
Storm date Griswold / IA

May 16, 2026

3.5"
Signatures 3.5" Estimated 1.75"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Apr 23, 2026 Estimated-size surface
Storm date Griswold / IA

Apr 23, 2026

1"
Signatures 1" Estimated 0.5"
No ground reports filed Open report →
NEXRAD radar-signature map of the hail storm over Griswold, IA on Apr 9, 2026 NEXRAD surface
Storm date Griswold / IA

Apr 9, 2026

0.75"
Signatures 0.75"
No ground reports filed Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Mar 6, 2026 Estimated-size surface
Storm date Griswold / IA

Mar 6, 2026

1"
Signatures 1" Estimated 0.75"
2 ground reports Open report →
Radar-estimated hail-size map of the storm over Griswold, IA on Mar 5, 2026 Estimated-size surface
Storm date Griswold / IA

Mar 5, 2026

1"
Signatures 1"
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 Sep 15, 2026.