Storm day
Definition
- Related pages
- 5
- Last revised
- 23 August 2026
A storm day is a calendar date with severe weather on record: at least one hail, wind or tornado report filed under that date, nationally or near a place. It counts as one day whether it carries one report or hundreds, and the product organises the free record around it because a claim is about a date before anything else. The question every party brings is which day, and the days near a place with something on record are the first honest answer.
The unit has edges. A date is a date in the standard this archive files by, universal time, so a storm late on a central evening can be filed under the following day and one storm's reports can fall across two dates; the reviewed record keeps local time, converted here. A day near a place is measured from the place's centre within a stated radius, so neighbouring towns share days. And a recent day is provisional while the national sources are still revising it, which the day's page says until the revision window closes.
Each storm day carries the figures a day can carry without an address: reports by kind, the largest size measured and the largest detected, how many independent sources carried it and how many states it was filed under. A day reaching a stated count of reports, or on which significant hail was measured and more than one source carried it, gets an indexed page; thinner days render too, so a citation to one resolves to a page that says what little there is.
In the report
How the document prints it
The report is compiled for a window rather than a day, and within it every storm day near the address is listed with its largest measured size, its largest detected size, its count of reports and its count of independent sources, so a reader can see whether the day a claim names is the best-attested day in the window or whether a stronger day sits a week away. Each finding prints the number of days it rests on and the most recent of them, and each record in the table carries its date, so the document can be read day by day as well as source by source.
From the record
23 Aug 2026
The most recent storm day with its own indexed page
- Hail reports on the day
- 40
- Largest measured on the ground
- 1.75″
- Independent sources
- 2
- States filed under
- 14
23 August 2026 carries 40 hail reports, the largest measured on the ground 1.75″, filed under 14 states and carried by 2 independent sources. A day earns an indexed page at 25 hail reports, or when hail of 2.00″ or more was measured and two or more sources carried it; this one clears the count.
Measured Detected, not measured
The page these figures come fromRelated
The terms this page uses and the guides that go further. Each is shown against its own example from the record.
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Term
Independent source
A record-keeping route by which a storm reached the archive, counted once however many rows it produced, so that agreement between routes can be measured.
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Term
Date of loss
The calendar date a claim says the damage occurred, which the storm record either holds a report for or does not.
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Term
SPC storm report
A preliminary hail, wind or tornado report collected nationally by the Storm Prediction Center from forecast offices on the day it was filed.
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Guide
Which storm caused it: attributing damage across several storm days
Most roofs in the hail belt have been under more than one storm, and a claim is rarely argued against a blank record. It is argued against the other days: the one before the policy began, the one the last carrier paid, the one nobody noticed. This guide sets out what the law asks when storms compete for the same damage, how an appraisal panel reads the record, and why the calendar has to be on the table before the argument starts.
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Term
Prior storm
An earlier storm that reached the same property before the one a claim is about, and the usual reason a hail claim is disputed.
Sources
The primary references. Each opens on the agency's own site.
The finder lists every day with hail on record within 10 miles of an address in the last 2 years, ranked by how many independent sources carried it, so the day a file names is a day the record holds.
The glossary defines the word. The report is what uses it.
Everything above is definition: what the word means in the document, and what it does not. None of it says what reached one roof.
Run the address and the archive is searched at the property: the storm, the date, the measured size, the distance and bearing from the roof, and the federal record each figure came from, in a document that states its own method. About a minute.
How this page is made
- The text
- Written by the editors and last revised 23 August 2026. It explains the record and how the report reads it; it contains no figure of its own.
- The example
- Drawn from the archive when the page was compiled, 24 August 2026, and rebuilt daily as the record deepens. Every figure in the panel marked From the record is computed, not written, and links to the page it came from.
- Measured and detected
- A report from a person or an instrument is measured. A radar-derived size is detected, not measured, and is marked as such, here and in every document we issue. The two are never added together.
- What this is not
- A definition of a word the report uses. It is not a report on any property, and it states no opinion about one. The coverage page states what the record holds, by kind and by year.
About this record
Everything here is reproduced from public federal and volunteer weather records, as the agencies and observer networks that publish them released it. Titan Weather compiles the record; it does not observe the weather, and it is not affiliated with any source it cites.
No archive holds everything. Storms cross places where nobody is standing, instruments and spotters cover some areas better than others, sources revise their records, and recent reports can take weeks to arrive and settle. Where this page shows nothing, nothing was found in the sources searched, within the period and area it states. That is not a finding that no weather occurred.
These pages describe the public record near a place or on a date. They do not establish what reached any particular property, and nothing here is insurance, legal or engineering advice.