Hail size 1"
1 SW Saint Paul St. Charles County
“(LSX)”
— NOAA / SPC storm report
/ Storm field report · St. Charles
Hail in O Fallon · Sep 17, 2026
Hit 4 days ago
The estimated-size surface reached 1" aloft; NEXRAD logged no point detections over O Fallon that day. Open it on the live map to see the swath over the streets.
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Peak hail signal 1" ≈ quarter · radar-estimated size aloft
Homes in the hail footprint 1,931
Ground reports 1 1 hail
Radar surfaces 1 Estimated size only
Convective day · Sep 17, 2026 · noon–noon UTC
Severity
The 2nd most severe storm O Fallon has seen in the last 12 months
Composite score · 3.4 / 10
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
3.4 /10
- Peak hail signal
- 25 /100
- Homes exposed
- 66 /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 O Fallon saw the hail — from two instruments
Sep 17, 2026 · O Fallon, MO
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.
Radar-estimated hail size Surface resolved
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.
Max size
1"
Only the radar-estimated size surface resolved for Sep 17, 2026 — this storm produced no NEXRAD point detections over O Fallon, so there is one map to show, not two.
The storm in context
Where Sep 17, 2026 sits in O Fallon's hail record.
This was O Fallon's 4th recorded hail day, arriving 124 days after the May 16, 2026 storm. By severity it ranks 2nd of the 4 storms we have logged here. Radar put the day's largest stone over O Fallon at 1" — radar-estimated size aloft.
The Sep 17, 2026 convective day was bigger than O Fallon: the same system put hail over 75 other tracked cities, 5 of them in Missouri. Nearest: Lake Saint Louis (7 miles south, up to 1"); Wright City (13 miles southwest, up to 0.5"); Hamburg (21 miles north, up to 0.5").
These maps are stills. In the app this date is one of 4 O Fallon 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.
Hail reports
1 reportStorm forensics
How the storm moved
Timing and place names from NOAA ground reports
Read from the arrival times and locations of the NOAA ground reports, not a radar-measured storm track.
Reports came from Saint Paul — beyond O Fallon itself.
Damage-capable hail signal
What 1" hail means for O Fallon 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.
1,931 homes × $12,000 avg. claim
Potential roof exposure
$23M
Potential roof exposure — 1,931 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
- Illustrative jobs
- 10 jobs
- Illustrative work
- ~$150K
Close just 0.5% of the 1,931 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 $406 on top of the $150 plan.
O Fallon hail history
Other storms in O Fallon.
4 recorded storm days in O Fallon, MO
Estimated-size surface Storm date O Fallon / MO
May 16, 2026
1.25" Signatures 1.25" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date O Fallon / MO
Apr 27, 2026
1.75" Signatures 1.75" Estimated 0.75"
6 ground reports Open report →
Estimated-size surface Storm date O Fallon / MO
Apr 17, 2026
1.5" Signatures 1.5" Estimated 0.75"
No ground reports filed Open report →
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Set your territory and alerts today. When hail hits, use Overview to choose your streets and get moving.
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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 18, 2026.