Alert archive / Idaho / Valley County

Weather alerts in Valley County, Idaho, 2020

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

Valley County and its neighbors

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

Alerts
48
Warnings
19
Watches
9
Advisories
12
Busiest month
August15 alerts
Busiest day
August 18, 20204 alerts

Over time

By month

Warning verification

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

Valley County, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings20100%30%
Flash flood warnings00

Each office's whole area, 2020

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Boise, ID: severe thunderstorm warnings47687%4030%20 min
NWS Boise, ID: flash flood warnings010%

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
Jan 8, 2:44 PM MSTWinter Storm WatchBOI37 hr
Jan 10, 3:29 AM MSTWinter Storm WarningBOI5 days
Jan 16, 3:20 AM MSTWinter Weather AdvisoryBOI30 hr
Jan 27, 9:51 AM MSTWinter Weather AdvisoryBOI31 hr
Feb 4, 3:02 AM MSTWinter Weather AdvisoryBOI56 hr
Feb 14, 1:28 PM MSTWinter Weather AdvisoryBOI49 hr
Feb 23, 3:34 PM MSTHigh Wind WarningBOI7 hr
Apr 29, 8:34 PM MDTSpecial Weather StatementMSO41 min
May 17, 3:01 PM MDTMesoscale DiscussionSPC119 min
May 30, 7:14 PM MDTSpecial Weather StatementBOI46 min
May 31, 2:38 AM MDTMesoscale DiscussionSPC2 hr
Jun 5, 1:46 PM MDTMesoscale DiscussionSPC119 min
Jun 12, 2:52 PM MDTWind AdvisoryBOI11 hr
Jun 24, 2:29 PM MDTMesoscale DiscussionSPC2 hr
Jun 28, 3:55 AM MDTFlash Flood WatchBOI10 hr
Aug 5, 1:14 PM MDTRed Flag WarningPIH32 hr
Aug 6, 12:47 PM MDTRed Flag WarningBOI17 hr
Aug 14, 9:16 AM MDTExcessive Heat WatchBOI28 hr
Aug 16, 7:56 AM MDTRed Flag WarningBOI4 days
Aug 17, 12:22 PM MDTRed Flag WarningPIH34 hr
Aug 17, 6:51 PM MDTSevere Thunderstorm WarningBOI39 min
Aug 17, 7:20 PM MDTSevere Thunderstorm WarningBOI25 min
Aug 18, 12:58 PM MDTRed Flag WarningBOI34 hr
Aug 18, 4:21 PM MDTMesoscale DiscussionSPC84 min
Aug 25, 3:28 AM MDTRed Flag WarningPIH18 hr
Aug 26, 3:29 AM MDTRed Flag WarningPIH41 hr
Aug 26, 8:12 AM MDTRed Flag WarningBOI16 hr
Aug 26, 7:04 PM MDTMesoscale DiscussionSPC116 min
Aug 28, 2:22 AM MDTFire Weather WatchPIH10 hr
Aug 28, 12:34 PM MDTRed Flag WarningPIH33 hr
Sep 3, 1:36 PM MDTFire Weather WatchPIH25 hr
Sep 4, 2:59 PM MDTRed Flag WarningBOI30 hr
Sep 4, 3:03 PM MDTRed Flag WarningPIH30 hr
Sep 13, 2:21 AM MDTFire Weather WatchPIH12 hr
Sep 13, 2:00 PM MDTRed Flag WarningPIH31 hr
Sep 15, 2:06 PM MDTFire Weather WatchPIH24 hr
Sep 15, 2:45 PM MDTFire Weather WatchBOI48 hr
Sep 16, 1:50 PM MDTRed Flag WarningPIH55 hr
Sep 16, 2:53 PM MDTRed Flag WarningBOI54 hr
Oct 13, 3:13 AM MDTFrost AdvisoryBOI54 hr
Nov 11, 2:50 PM MSTWinter Storm WatchBOI23 hr
Nov 12, 1:44 PM MSTWinter Storm WarningBOI32 hr
Nov 14, 3:51 AM MSTWinter Weather AdvisoryBOI31 hr
Nov 30, 2:34 PM MSTAir Stagnation AdvisoryBOI10 days
Dec 15, 2:17 PM MSTWinter Weather AdvisoryBOI45 hr
Dec 18, 2:14 PM MSTWinter Weather AdvisoryBOI42 hr
Dec 24, 2:29 AM MSTWinter Weather AdvisoryBOI63 hr
Dec 30, 2:30 AM MSTWinter Weather AdvisoryBOI27 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.