Alert archive / Utah / Salt Lake County

Weather alerts in Salt Lake County, Utah, 2020

57 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Salt Lake County and its neighbors

Each county as a circle sized by its count in 2020. Tap one for its archive.

Alerts
57
Warnings
27
Watches
13
Advisories
1
Busiest month
June22 alerts
Busiest day
June 6, 20207 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

Salt Lake County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings6517%1443%24 min
Flash flood warnings00

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Salt Lake City, UT: severe thunderstorm warnings341944%9340%17 min
NWS Salt Lake City, UT: flash flood warnings211052%1883%77 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.

IssuedProductOfficeLasted
May 30, 3:08 PM MDTSevere Thunderstorm WarningSLC37 min
May 30, 5:06 PM MDTSevere Thunderstorm WarningSLC24 min
May 30, 5:29 PM MDTSevere Thunderstorm WarningSLC31 min
Jun 3, 1:03 PM MDTFire Weather WatchSLC23 hr
Jun 4, 12:24 PM MDTRed Flag WarningSLC33 hr
Jun 5, 6:06 PM MDTSevere Thunderstorm WarningSLC54 min
Jun 5, 6:24 PM MDTMesoscale DiscussionSPC96 min
Jun 5, 6:33 PM MDTSevere Thunderstorm WarningSLC42 min
Jun 6, 7:14 AM MDTSpecial Weather StatementSLC46 min
Jun 6, 1:23 PM MDTSpecial Weather StatementSLC52 min
Jun 6, 4:18 PM MDTSpecial Weather StatementSLC42 min
Jun 6, 4:56 PM MDTSpecial Weather StatementSLC49 min
Jun 7, 9:50 AM MDTSpecial Weather StatementSLC40 min
Jun 7, 10:28 AM MDTMesoscale DiscussionSPC2 hr
Jun 7, 10:32 AM MDTSpecial Weather StatementSLC43 min
Jun 7, 10:59 AM MDTAreal Flood AdvisorySLC91 min
Jun 7, 12:10 PM MDTSpecial Weather StatementSLC50 min
Jun 11, 3:18 AM MDTRed Flag WarningSLC66 hr
Jun 14, 12:51 PM MDTRed Flag WarningSLC56 hr
Jun 25, 2:19 PM MDTFire Weather WatchSLC24 hr
Jun 26, 2:33 PM MDTRed Flag WarningSLC3 days
Jun 28, 12:27 PM MDTSpecial Weather StatementSLC33 min
Jun 28, 12:52 PM MDTSpecial Weather StatementSLC23 min
Jun 28, 3:18 PM MDTSpecial Weather StatementSLC57 min
Jun 28, 4:08 PM MDTSevere Thunderstorm WarningSLC22 min
Jul 20, 2:00 PM MDTFire Weather WatchSLC25 hr
Jul 21, 2:48 PM MDTRed Flag WarningSLC31 hr
Jul 26, 5:36 PM MDTSpecial Weather StatementSLC24 min
Jul 27, 5:27 PM MDTSpecial Weather StatementSLC33 min
Aug 2, 2:10 PM MDTRed Flag WarningSLC32 hr
Aug 4, 3:21 AM MDTRed Flag WarningSLC66 hr
Aug 8, 2:29 PM MDTRed Flag WarningSLC55 hr
Aug 10, 2:14 PM MDTRed Flag WarningSLC3 days
Aug 11, 3:15 AM MDTFire Weather WatchSLC12 hr
Aug 18, 3:20 PM MDTFire Weather WatchSLC23 hr
Aug 19, 2:36 PM MDTRed Flag WarningSLC30 hr
Aug 22, 2:37 PM MDTRed Flag WarningSLC30 hr
Aug 24, 8:20 PM MDTSpecial Weather StatementSLC70 min
Aug 26, 11:28 PM MDTSpecial Weather StatementSLC32 min
Aug 27, 3:09 AM MDTRed Flag WarningSLC17 hr
Aug 28, 3:06 AM MDTFire Weather WatchSLC12 hr
Aug 28, 2:54 PM MDTRed Flag WarningSLC3 days
Sep 3, 2:29 PM MDTFire Weather WatchSLC24 hr
Sep 4, 2:43 PM MDTFire Weather WatchSLC48 hr
Sep 4, 2:43 PM MDTRed Flag WarningSLC4 days
Sep 13, 11:32 AM MDTRed Flag WarningSLC33 hr
Sep 15, 2:00 PM MDTFire Weather WatchSLC48 hr
Sep 16, 2:49 PM MDTRed Flag WarningSLC3 days
Sep 22, 2:28 PM MDTFire Weather WatchSLC21 hr
Sep 23, 11:34 AM MDTRed Flag WarningSLC3 days
Oct 3, 2:57 PM MDTFire Weather WatchSLC24 hr
Oct 4, 2:58 PM MDTRed Flag WarningSLC29 hr
Oct 8, 2:34 PM MDTFire Weather WatchSLC24 hr
Oct 9, 2:34 PM MDTRed Flag WarningSLC54 hr
Oct 20, 2:36 PM MDTRed Flag WarningSLC54 hr
Nov 4, 2:35 PM MSTFire Weather WatchSLC24 hr
Nov 5, 2:39 PM MSTRed Flag WarningSLC30 hr

By product

Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force nowTornadoes on recordForecastThe radar archive20192021

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.