Alert archive / Idaho / Flash Flood Warnings
Flash Flood Warnings in Idaho, 2023
58 flash flood warnings in 2023. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of flash flood warnings reaches back to 1986.
Flash Flood Warnings by county
Each county as a circle sized by its count in 2023. Tap one for its archive.
- Flash Flood Warnings
- 58
- Busiest month
- May26 flash flood warnings
- Busiest day
- May 26, 20238 flash flood warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
13 of 58 flash flood warnings covering Idaho in 2023 had a flash flood report inside them; 43 of 56 flash flood reports fell inside a warning, on average 48 minutes after it went out.
Idaho, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Flash flood warnings | 58 | 13 | 78% | 56 | 77% | 48 min |
Each office's whole area, 2023
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Spokane, WA: flash flood warnings | 18 | 4 | 78% | 49 | 49% | 32 min |
| NWS Boise, ID: flash flood warnings | 13 | 3 | 77% | 4 | 75% | 62 min |
| NWS Pocatello, ID: flash flood warnings | 42 | 8 | 81% | 30 | 77% | 60 min |
| NWS Missoula, MT: flash flood warnings | 7 | 2 | 71% | 4 | 100% | 29 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
Every alert, in the order issued. Times are local, Mountain Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 2, 6:40 PM MDT | Flash Flood Warning | OTX | Shoshone | 3 hr |
| May 23, 6:45 PM MDT | Flash Flood Warning | PIH | Bingham, Bonneville | 3 hr |
| May 23, 6:56 PM MDT | Flash Flood Warning | PIH | Madison | 3 hr |
| May 24, 2:11 PM MDT | Flash Flood Warning | PIH | Cassia | 5 hr |
| May 24, 3:31 PM MDT | Flash Flood Warning | PIH | Bannock, Bingham | 97 min |
| May 24, 3:40 PM MDT | Flash Flood Warning | PIH | Cassia, Minidoka | 3 hr |
| May 26, 12:42 PM MDT | Flash Flood Warning | PIH | Bonneville, Jefferson | 3 hr |
| May 26, 1:35 PM MDT | Flash Flood Warning | PIH | Cassia | 5 hr |
| May 26, 2:48 PM MDT | Flash Flood Warning | PIH | Bingham | 3 hr |
| May 26, 3:04 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| May 26, 3:14 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| May 26, 4:55 PM MDT | Flash Flood Warning | PIH | Bannock, Oneida, Power | 3 hr |
| May 26, 5:25 PM MDT | Flash Flood Warning | PIH | Blaine, Butte, Custer | 3 hr |
| May 26, 5:41 PM MDT | Flash Flood Warning | PIH | Butte, Clark | 3 hr |
| May 27, 2:05 PM MDT | Flash Flood Warning | BOI | Gem | 3 hr |
| May 29, 3:38 PM MDT | Flash Flood Warning | PIH | Cassia, Power | 5 hr |
| May 29, 4:24 PM MDT | Flash Flood Warning | PIH | Bannock, Caribou | 4 hr |
| May 29, 4:30 PM MDT | Flash Flood Warning | PIH | Cassia | 4 hr |
| May 29, 4:40 PM MDT | Flash Flood Warning | PIH | Cassia | 4 hr |
| May 30, 12:55 PM MDT | Flash Flood Warning | PIH | Blaine, Butte, Custer | 3 hr |
| May 30, 1:27 PM MDT | Flash Flood Warning | PIH | Blaine | 2 hr |
| May 30, 3:55 PM MDT | Flash Flood Warning | BOI | Boise | 47 min |
| May 30, 6:15 PM MDT | Flash Flood Warning | PIH | Bannock, Power | 3 hr |
| May 31, 2:30 PM MDT | Flash Flood Warning | PIH | Butte, Custer | 3 hr |
| May 31, 4:20 PM MDT | Flash Flood Warning | PIH | Cassia | 4 hr |
| May 31, 4:57 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| Jun 4, 2:44 PM MDT | Flash Flood Warning | PIH | Bingham, Bonneville | 82 min |
| Jun 6, 3:31 PM MDT | Flash Flood Warning | MSO | Lemhi | 2 hr |
| Jun 6, 4:23 PM MDT | Flash Flood Warning | PIH | Blaine | 81 min |
| Jun 6, 5:02 PM MDT | Flash Flood Warning | MSO | Lemhi | 118 min |
| Jun 6, 9:00 PM MDT | Flash Flood Warning | BOI | Ada | 3 hr |
| Jun 7, 8:19 PM MDT | Flash Flood Warning | PIH | Cassia | 116 min |
| Jun 8, 2:03 PM MDT | Flash Flood Warning | PIH | Cassia | 3 hr |
| Jun 9, 3:43 PM MDT | Flash Flood Warning | OTX | Nez Perce | 110 min |
| Jun 9, 4:12 PM MDT | Flash Flood Warning | PIH | Blaine | 3 hr |
| Jun 12, 1:19 PM MDT | Flash Flood Warning | PIH | Butte, Custer | 114 min |
| Jun 12, 5:37 PM MDT | Flash Flood Warning | PIH | Bingham, Bonneville | 56 min |
| Jun 12, 6:04 PM MDT | Flash Flood Warning | PIH | Bonneville | 27 min |
| Jun 13, 3:16 PM MDT | Flash Flood Warning | PIH | Bannock, Bingham, Caribou | 70 min |
| Jun 13, 5:43 PM MDT | Flash Flood Warning | PIH | Blaine, Lincoln | 75 min |
| Jun 13, 5:45 PM MDT | Flash Flood Warning | PIH | Blaine, Lincoln, Minidoka | 47 min |
| Jun 13, 7:10 PM MDT | Flash Flood Warning | PIH | Cassia | 2 hr |
| Jun 13, 11:36 PM MDT | Flash Flood Warning | PIH | Clark | 4 hr |
| Jul 8, 5:30 PM MDT | Flash Flood Warning | PIH | Teton | 79 min |
| Jul 20, 6:04 PM MDT | Flash Flood Warning | PIH | Franklin | 119 min |
| Aug 2, 4:21 PM MDT | Flash Flood Warning | BOI | Elmore | 3 hr |
| Aug 2, 7:17 PM MDT | Flash Flood Warning | BOI | Boise | 3 hr |
| Aug 4, 4:25 PM MDT | Flash Flood Warning | BOI | Camas | 106 min |
| Aug 5, 5:58 PM MDT | Flash Flood Warning | MSO | Lemhi | 3 hr |
| Aug 5, 7:15 PM MDT | Flash Flood Warning | MSO | Lemhi | 94 min |
| Aug 7, 6:16 PM MDT | Flash Flood Warning | BOI | Ada, Boise | 3 hr |
| Aug 17, 3:09 PM MDT | Flash Flood Warning | PIH | Bannock, Power | 3 hr |
| Aug 17, 3:44 PM MDT | Flash Flood Warning | PIH | Power | 3 hr |
| Aug 18, 7:05 PM MDT | Flash Flood Warning | BOI | Adams, Gem, Valley | 23 min |
| Aug 21, 9:02 AM MDT | Flash Flood Warning | PIH | Blaine | 6 hr |
| Aug 21, 4:41 PM MDT | Flash Flood Warning | BOI | Gooding | 4 hr |
| Aug 21, 5:28 PM MDT | Flash Flood Warning | PIH | Blaine | 3 hr |
| Aug 29, 4:54 PM MDT | Flash Flood Warning | MSO | Idaho | 114 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Cassia County13
- Blaine County9
- Bingham County6
- Bannock County6
- Bonneville County5
- Power County5
- Butte County5
- Custer County4
- Lemhi County4
- Boise County3
- Minidoka County2
- Clark County2
- Gem County2
- Caribou County2
- Ada County2
- Lincoln County2
- Shoshone County1
- Madison County1
- Jefferson County1
- Oneida County1
- Nez Perce County1
- Teton County1
- Franklin County1
- Elmore County1
- Camas County1
- Adams County1
- Valley County1
- Gooding County1
- Idaho County1
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20222024
Sources
National Weather Service watches, warnings, advisories and statements from the Iowa Environmental Mesonet's VTEC archive, which reconstructs tornado, severe thunderstorm, flash flood and marine warnings back to 1986 from the NWS text archive. Storm Prediction Center watches and mesoscale discussions from SPC's archive through the Mesonet. County centers from the US Census Bureau. Warning verification from the Mesonet's Cow. Rebuilt daily.