How the tracker's warnings and closure record hold up, measured on its own data and updated through the day.
Closing-soon warnings
The tracker raises a closing-soon warning when it expects a station to close soon. Drivers with alerts on may be sent it, but not every warning reaches someone: quiet hours, a driver's plan and muted stations decide who is sent each one. The figures below count every closing-soon warning the tracker raised. Each one is checked 22 minutes later: did the tracker's status for that station turn to closed in that time, and how long after the warning was raised?
| Since the record began | |
|---|---|
| Closing-soon warnings raised by the tracker | 6,732 |
| Followed by a closure within 22 minutes | 1,643 |
| Share followed by a closure | 24% |
| Median warning time before the closure, counted from when the tracker raised the warning | 8 min |
By kind of warning
| Kind | Since the record began | Median warning time (since the record began) |
|---|---|---|
| 20-minute lightning prediction | 395 of 605 (65%) | 6 min |
| Lightning and storm advisories | 1,248 of 6,127 (20%) | 9 min |
| Tornado warnings | None raised | — |
Each cell: the warnings followed by a closure, of the closing-soon warnings the tracker raised, and that share.
Day by day, since the record began (UTC days)
| Day | Warnings raised | Followed by a closure | Share |
|---|---|---|---|
| Thu, Oct 8, 2026 (so far) | 297 | 89 | 30% |
| Wed, Oct 7, 2026 | 1,431 | 288 | 20% |
| Tue, Oct 6, 2026 | 1,397 | 259 | 19% |
| Mon, Oct 5, 2026 | 1,543 | 396 | 26% |
| Sun, Oct 4, 2026 | 1,301 | 364 | 28% |
| Sat, Oct 3, 2026 | 763 | 247 | 32% |
The figures above count these same UTC days: today so far and the days before it. The warning record began on Oct 2, 2026 (ET).
The closure record
In the last 30 days the tracker recorded 1,473 closures at 704 stations in the United States.
| Measure | Last 30 days |
|---|---|
| Closures recorded | 1,473 |
| Median closure length | 37 min |
| 9 in 10 closures lasted at most | 1 h 20 min |
| Share of the time since the record began that the tracker was watching | 100.0% |
Lengths are from the 1,449 closures whose start and end the tracker saw; ones still in progress or with an unseen start or end are left out of them. The record began on Sep 27, 2026 (ET), so these figures cover only the time since.
| Cause | Closures | Share |
|---|---|---|
| Lightning | 1,467 | 100% |
| In progress (cause shown once it ends) | 6 | 0% |
Every closure is listed day by day in the closure archive.
How this is measured
- A warning counts as followed by a closure when the tracker's status for that station turned to closed within 22 minutes of the warning. The warning time is how long before that closure the tracker raised the warning.
- Every closing-soon warning the tracker raised is counted, whether or not a driver was sent it: quiet hours, a driver's plan and muted stations decide who is sent each one.
- Closures are the tracker's own record: stretches when the weather reports at a station were of the kind that comes with a closure. They are not confirmed station decisions; station leadership makes the final call.
- Warnings raised while the tracker was not watching (offline, or its weather reports out of date) are left out, since there is no way to check them.
- The 20-minute lightning prediction is expected to be right roughly three times in four. A warning that was not followed by a closure is not always wrong: a storm can weaken or pass to one side.
- Warning figures are counted by UTC day: the last 7 and 30 days are today so far and the 6 or 29 days before it, the same days as the day-by-day table. A closure counts in the last 30 days when any part of it falls in them, as on the station pages; a closure still in progress shows its cause once it ends.