Reference · For newsrooms and analysts
MESH, Defined: How to Read and Label Radar Hail Estimates
MESH — Maximum Estimated Size of Hail — is NOAA's radar estimate of the largest hailstone a storm likely produced at each point on a roughly 1-kilometre national grid, derived from reflectivity above the freezing level and published through the Multi-Radar/Multi-Sensor (MRMS) system. Radar-estimated MESH ≥1″ is preliminary; size is a class, not a measurement, and this is not a damage outline.
This page is the reference HailScore™ cites, and the one it asks others to cite, whenever a radar hail figure is published. If you are looking for the plain-English explainer instead, read what is MRMS MESH.
Is MESH the same as hail size on the ground?
No. MESH is calculated from what the radar sees above the storm, not from anyone measuring a stone where it landed. MESH is tuned so that roughly 75% of measured hail comes in at or below the radar estimate; read a size as a class (within about one tier), not as a measurement. So a MESH figure answers "what size band was estimated over this area", never "what size hail fell at this address".
What does MESH ≥1″ mean?
It means the radar's estimate for that grid cell was 1″ or larger — roughly a quarter — which is the floor below which HailScore publishes no footprint at all. Above the floor, sizes are published in bands (1–1.5″, 1.5–2″, 2–2.5″, 2.5″+). A cell in the 1–1.5″ band is not a claim that a specific stone of that diameter fell there; it is a claim that the estimate for that cell fell in that band.
Is this a damage outline?
No. A MESH footprint shows where hail of a given estimated size was likely present. That is exposure, not outcome. Whether a particular roof was harmed depends on things radar cannot see — the roof's age, its material, its pitch, and how the stones actually struck it — so a property inside a footprint has not been found to be damaged, and only an inspection can establish that.
Where does MESH come from, and how fresh is it?
MRMS is a NOAA system that merges the entire NEXRAD radar network with satellite, surface, and lightning data into one seamless national grid, updating every couple of minutes. MESH is one product within it. HailScore ingests MESH within about two hours of a storm, which is why a record can exist the same day while NOAA's ground-verified Storm Events archive is still months from publishing.
How should journalists label MESH?
Call it radar-estimated hail size from NOAA MRMS MESH — size is a class, not a measurement — and describe the footprint as estimated hail exposure, not a damage outline.
Accurate
- “Radar estimated hail up to the 2–2.5″ range near Pueblo.”
- “NOAA MRMS MESH, a radar estimate, put the day’s largest hail in that band.”
- “The map shows estimated hail exposure, not confirmed damage.”
Avoid
- “2.3-inch hail fell on Elm Street.” A grid estimate is not a street-level measurement.
- “Damage map” or “damage swath.” The footprint is exposure.
- Any margin of error on the size. The tuning is a one-directional bias, not an error bar.
What does a real MESH record look like?
A Colorado storm day whose peak reaches 1.5″ in a Front Range county, or 2″ anywhere in Colorado gets a dated public record page, with the day's cells mapped, each size labelled as a band and each source named. Smaller days still appear on the maps down to the 1″ legend floor; they do not get a page of their own. Those pages are the worked example of everything on this page.
Worked example: June 24, 2026 — Pueblo County, Colorado. The full set is indexed at /storm.
Source-cited, not a verdict
Every size HailScore™ publishes is a government publisher’s own reading — NOAA NEXRAD and Storm Events, NCEP MRMS MESH, CoCoRaHS — radar-estimated or ground-reported hail exposure near a location. It is not a damage determination, not a verified reading at any one roof, and not a legal finding; confirm damage with an inspection.
Embed a storm record in your story
A card for one Colorado storm day: the date, the county, the peak size class, and the caveat above, with links back to the full record. It is the honesty line travelling with the number onto your page. Free to use with the attribution the card already carries.
Filled example — June 24, 2026 — Pueblo County, Colorado
<iframe src="https://www.myhailscore.com/embed/storm/2026-06-24/pueblo-county-co" width="100%" height="360" style="border:0;" title="Hail record — HailScore" loading="lazy"></iframe>Preview it live: /embed/storm/2026-06-24/pueblo-county-co.
Any storm day — swap the two placeholders
<iframe src="https://www.myhailscore.com/embed/storm/YYYY-MM-DD/county-slug" width="100%" height="360" style="border:0;" title="Hail record — HailScore" loading="lazy"></iframe>YYYY-MM-DDis the storm date, as the Mountain-Time calendar day the hail fell.county-slugis the county slug, likepueblo-county-co. Browse /storm and copy the two segments out of any storm URL.- A date and county with no qualifying record returns 404 rather than an empty card, so a wrong slug fails visibly instead of publishing a blank box.
The card sets its own height at 360px and is not indexed — the canonical, citable page is always the storm record it links to. Questions: /press.
Cite this page
HailScore, “MESH, Defined: How to Read and Label Radar Hail Estimates.” Available at https://www.myhailscore.com/mesh.Press and data questions: /press. The scoring white paper, including the works cited for the MESH algorithm, is at /methodology.
Sources
- NOAA NSSL — Multi-Radar/Multi-Sensor (MRMS) system
- NOAA NCEI — Severe Weather Data Inventory (NEXRAD)
- Witt, A., et al. (1998). An Enhanced Hail Detection Algorithm for the WSR-88D. Weather and Forecasting, 13(2), 286–303.
Related
Check a specific address
A MESH footprint covers an area. To see the storm record for one property, with every event dated and its publisher named, run the free address check.
Did hail hit my address?