Alert archive / Nevada / Clark County / Flash Flood Warnings

Flash Flood Warnings in Clark County, Nevada, 2023

52 flash flood warnings in 2023. An alert counts here when it covered this county. The archive of flash flood warnings reaches back to 1986.

Clark County and its neighbors

Each county as a circle sized by its count in 2023. Tap one for its archive.

Flash Flood Warnings
52
Busiest month
September26 flash flood warnings
Busiest day
September 1, 202312 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.

25 of 52 flash flood warnings covering Clark County in 2023 had a flash flood report inside them; 46 of 63 flash flood reports fell inside a warning, on average 105 minutes after it went out.

Clark County, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Flash flood warnings522552%6373%105 min

Each office's whole area, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Las Vegas, NV: flash flood warnings1465662%18468%114 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, Pacific Time. Each opens its own page with the text, the map, the radar and the sounding.

IssuedProductOfficeLasted
Mar 15, 3:51 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Mar 15, 4:16 PM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Mar 15, 6:34 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Jun 11, 5:17 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Jul 17, 3:25 PM PDTFlash Flood Warning Considerable damage threatVEF2 hr
Jul 31, 10:27 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 1, 1:16 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 1, 5:03 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 1, 5:58 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 1, 6:35 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 11, 4:23 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 11, 5:33 PM PDTFlash Flood Warning Considerable damage threatVEF111 min
Aug 16, 1:19 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 16, 1:35 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 18, 3:29 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 18, 3:48 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 18, 4:09 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 18, 5:40 PM PDTFlash Flood Warning Considerable damage threatVEF5 hr
Aug 18, 6:28 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 20, 6:56 PM PDTFlash Flood Warning Considerable damage threatVEF7 hr
Aug 20, 8:19 PM PDTFlash Flood Warning Considerable damage threatVEF5 hr
Aug 21, 12:56 AM PDTFlash Flood WarningVEF8 hr
Aug 21, 2:30 AM PDTFlash Flood WarningVEF16 hr
Aug 24, 1:30 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 24, 3:14 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Aug 24, 3:38 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 1:38 AM PDTFlash Flood Warning Considerable damage threatVEF5 hr
Sep 1, 3:29 AM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 1, 5:03 AM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 7:07 AM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 12:05 PM PDTFlash Flood Warning Considerable damage threatVEF10 hr
Sep 1, 12:40 PM PDTFlash Flood Warning Considerable damage threatVEF6 hr
Sep 1, 1:25 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 1:30 PM PDTFlash Flood Warning Considerable damage threatVEF5 hr
Sep 1, 2:44 PM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 1, 3:28 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 3:33 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 3:51 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 1, 5:37 PM PDTFlash Flood Warning Considerable damage threatVEF8 hr
Sep 1, 5:51 PM PDTFlash Flood Warning Considerable damage threatVEF69 min
Sep 1, 6:38 PM PDTFlash Flood Warning Considerable damage threatVEF7 hr
Sep 1, 7:10 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 2, 11:29 AM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 2, 1:26 PM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 2, 1:57 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 2, 3:57 PM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 2, 4:47 PM PDTFlash Flood Warning Considerable damage threatVEF4 hr
Sep 12, 3:29 PM PDTFlash Flood Warning Considerable damage threatVEF2 hr
Sep 12, 3:40 PM PDTFlash Flood Warning Considerable damage threatVEF110 min
Sep 12, 5:07 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 14, 12:16 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr
Sep 20, 3:18 PM PDTFlash Flood Warning Considerable damage threatVEF3 hr

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe 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.