Tornado Rating unknown
6 S Gann Valley Buffalo County
“Tornado on the ground. (ABR)”
— NOAA / SPC storm report
Hail in Gann Valley Jul 2, 2026
Hit 32 days agoBoth radar surfaces caught this storm: NEXRAD logged 37 hail signatures up to 2.75", and the radar-estimated size reached 2.25" aloft. At 2.75" — baseball — this is severe, roof-replacing hail: close to every roof inside the footprint becomes a claim candidate.
A tornado was also reported to the National Weather Service during this storm — see the ground reports below.
Largest hailstone
2.75"
≈ baseball · the largest NEXRAD radar signature Homes in the hail footprint
161
Ground reports
7
3 hail · 2 wind · 2 tornadoThe most severe storm Gann Valley has seen in the last 12 months
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
6.7 /10
- Hail size
- 69 /100
- Homes exposed
- 44 /100
- Ground truth
- 100 /100
Largest hailstone — the top predictor of roof damage.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
How Gann Valley 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.
NEXRAD radar signatures
The point detections NEXRAD recorded overhead. Each signature marks where the radar saw hail aloft — it is a detection, not a stone measured on the ground.
Max size
2.75"
Detections
37
Radar-estimated hail size
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
2.25"
Where Jul 2, 2026 sits in Gann Valley's hail record
This was Gann Valley's 2nd recorded hail day, arriving 23 days after the Jun 9, 2026 storm. By severity it ranks 1st of the 3 storms we have logged here. Radar put the day's largest stone over Gann Valley at 2.75" — the largest NEXRAD radar signature.
The Jul 2, 2026 convective day was bigger than Gann Valley: the same system put hail over 1,147 other tracked cities, 153 of them in South Dakota. Nearest: Ree Heights (10 miles northwest, up to 2.5"); Pukwana (14 miles south, up to 2.75"); Miller (14 miles north, up to 0.75").
These maps are stills from Gann Valley's Jul 2, 2026 storm. In the Overview app the same surfaces are live — radar updating in real time, radar-estimated hail size as it forms, and NWS spotter reports pinned where they're filed — with a radar replay you can scrub back over any past day.
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.
Tornado reports
2 reports Tornado Rating unknown
2 E Gann Valley Buffalo County
“Several photos on X of a tornado on the ground near Gann Valley. Location estimated via radar. (ABR)”
— NOAA / SPC storm report
Hail reports
3 reports Hail size 2.75"
7 WNW Gann Valley Buffalo County
“report relayed via EM... golf ball to baseball size hail with heavy rain. Location and time estimated. (ABR)”
— NOAA / SPC storm report
Hail size 1.75"
7 SSW Gann Valley Buffalo County
“(ABR)”
— NOAA / SPC storm report
Hail size 3"
7 SSW Gann Valley Buffalo County
“Photo relayed via text... included spotter ruler card. (ABR)”
— NOAA / SPC storm report
Wind reports
2 reports Wind gust 81 mph
3 N Gann Valley Buffalo County
“Mesonet station 201 Gann Valley (SDDOT). (ABR)”
— NOAA / SPC storm report
Wind gust 62 mph
3 N Gann Valley Buffalo County
“Mesonet station 201 Gann Valley (SDDOT). (ABR)”
— NOAA / SPC storm report
Storm forensics
Read from the arrival times and locations of the NOAA ground reports,
not a radar-measured storm track.
How the storm moved
The storm tracked north at roughly 5 mph, based on the timing of ground reports.
Hail was reported over 110 minutes, from to .
What 2.75" hail means for Gann Valley roofs
Two-inch-plus hail punctures shingles, breaks skylights and windows, and dents anything soft. In the core of a footprint like this, close to every roof is a candidate for an insurance claim. Speed decides who writes those jobs.
What this storm is worth to a roofer
$1.9M
Potential roof exposure — 161 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Illustrative jobs
1 job
Illustrative work
~$15K
Claims from this storm can typically be filed until around July 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Track hail over Gann Valley on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Gann Valley storm history — this Jul 2, 2026 storm included — sits underneath. When you're ready, draw this storm's footprint and pull highly accurate homeowner contact information for every address inside it.
Highly accurate contact information starting at $0.23 per address — every contact included. Digital leads cost $15–$40. Start with a 7-day free trial — no credit card required. See pricing
Gann Valley hail history
← All hail in Gann Valley 3 recorded storm days in Gann Valley, SD
Other storms in Gann Valley
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 surfaces are detections and estimates,
not confirmed damage. Last updated Aug 3, 2026.