SPC storm report
Definition
- Related pages
- 5
- Last revised
- 23 August 2026
An SPC storm report is an entry in the national log the Storm Prediction Center keeps of the hail, wind and tornado reports forecast offices issue each day. The centre gathers every local storm report as it is sent, files it under the convective day it belongs to, and publishes the log as three lists with a time, a location, a county, a state, a magnitude where there is one and the text of the report. The lists are the quickest national view of a storm day and the record most people see first when they look a date up.
The centre calls the log preliminary and means it. Entries are copied from the offices' reports with little review; a wrong size or a duplicated location stays in the log as filed, and a storm nobody reported is absent from it. The same day is later reviewed by each office and carried into the national storm database, where entries are corrected, merged or removed, and the two records of one day can differ. The log is not retired; it remains the record of what was reported as the storm moved.
Duplicates are kept as filed. The log can carry one storm twice, from two offices or two callers, and the product does not merge them: the count here is the count the source published. The log is a separate source from the reviewed record even where an entry began as the same local storm report, and the two figures are held side by side rather than one overwriting the other.
In the report
How the document prints it
In the report a preliminary log entry is a row in the record table with its date, its type, its measurement, its distance and bearing from the address and its source, marked as measured, and its citation under Sources and method names the log, calls it preliminary and states the radius it was searched at. Where the reviewed database carries the same event, both rows are printed, each with its own source and number, so a reader can see where the figures agree and where the review changed one.
From the record
23 Aug 2026
A day whose preliminary record has not yet settled
- Reports on the day so far
- 177
- Shortest revision window
- 7 days
- Longest revision window
- 540 days
- Settles by
- 14 February 2028
23 August 2026 carries 177 reports so far. The national sources revise a day for between 7 and 540 days after it, so the figure is preliminary until 14 February 2028 and the day's page is marked provisional until then.
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
Local storm report
A report of severe weather at a place and a time, relayed by a National Weather Service office as it comes in and before it is reviewed.
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Term
Storm Events database
The federal archive of reviewed storm reports, compiled by forecast offices and published by NCEI between two and three months after each month ends.
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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
Storm day
A calendar date on which hail, wind or tornado reports were filed, counted as one day however many reports it carries.
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Guide
NOAA's Storm Events database, explained
The Storm Events database is the reviewed record of severe weather in the United States, kept by the National Centers for Environmental Information from the entries each forecast office prepares under a written directive. This guide states what is in it, how a hail entry is made, why it arrives a season after the storm and can change after that, what it does not hold, and how to read it beside the preliminary log and the local storm report an entry began as.
Sources
The primary references. Each opens on the agency's own site.
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.