Alert archive / California / Placer County

Weather alerts in Placer County, California, 2020

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

Placer County and its neighbors

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

Alerts: 121
Warnings: 27
Watches: 19
Advisories: 66
Busiest month: January16 alerts
Busiest day: April 5, 20205 alerts

Over time

By month

Warning verification

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

Placer County, 2020

	Warnings	With a report	False alarm ratio
Tornado warnings	0
Severe thunderstorm warnings	4	0	100%
Flash flood warnings	2	0	100%

Each office's whole area, 2020

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Reno, NV: tornado warnings	1	1	0%	3	33%	29 min
NWS Reno, NV: severe thunderstorm warnings	34	1	97%	8	13%	7 min
NWS Reno, NV: flash flood warnings	21	2	90%	5	60%	53 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.

Issued	Product	Office	Lasted
Jan 3, 3:01 AM PST	Lake Wind Advisory	REV	37 hr
Jan 7, 10:29 AM PST	Lake Wind Advisory	REV	18 hr
Jan 8, 3:24 AM PST	Winter Weather Advisory	REV	31 hr
Jan 10, 5:43 AM PST	Lake Wind Advisory	REV	6 hr
Jan 10, 11:53 AM PST	Lake Wind Advisory	REV	28 hr
Jan 10, 11:53 AM PST	Wind Advisory	REV	28 hr
Jan 11, 11:48 AM PST	Winter Weather Advisory	REV	70 hr
Jan 12, 3:40 AM PST	Lake Wind Advisory	REV	39 hr
Jan 12, 3:40 AM PST	Winter Storm Watch	REV	58 hr
Jan 13, 6:29 AM PST	Lake Wind Advisory	REV	37 hr
Jan 14, 1:33 PM PST	Winter Storm Warning	REV	55 hr
Jan 14, 1:33 PM PST	Winter Weather Advisory	REV	62 hr
Jan 16, 11:23 AM PST	Mesoscale Discussion	SPC	3 hr
Jan 20, 2:22 PM PST	Lake Wind Advisory	REV	32 hr
Jan 24, 1:48 PM PST	Lake Wind Advisory	REV	49 hr
Jan 31, 1:48 PM PST	Lake Wind Advisory	REV	53 hr
Feb 7, 2:07 PM PST	Lake Wind Advisory	REV	52 hr
Feb 7, 2:07 PM PST	Wind Advisory	REV	68 hr
Feb 10, 3:20 AM PST	Lake Wind Advisory	REV	13 hr
Feb 28, 2:38 AM PST	Lake Wind Advisory	REV	43 hr
Feb 28, 3:35 PM PST	Winter Weather Advisory	REV	48 hr
Mar 1, 4:02 AM PST	Lake Wind Advisory	REV	36 hr
Mar 6, 5:42 AM PST	Lake Wind Advisory	REV	34 hr
Mar 11, 1:53 PM PDT	High Wind Watch	REV	24 hr
Mar 11, 1:54 PM PDT	Winter Storm Watch	REV	49 hr
Mar 12, 2:02 PM PDT	Wind Advisory	REV	54 hr
Mar 13, 4:54 AM PDT	Winter Storm Warning	REV	3 days
Mar 13, 4:54 AM PDT	Winter Weather Advisory	REV	6 days
Mar 14, 1:53 PM PDT	Mesoscale Discussion	SPC	6 hr
Mar 18, 9:05 AM PDT	Winter Weather Advisory	REV	20 hr
Mar 22, 3:00 PM PDT	Lake Wind Advisory	REV	50 hr
Mar 23, 3:35 PM PDT	Winter Weather Advisory	REV	42 hr
Mar 29, 2:41 PM PDT	Lake Wind Advisory	REV	53 hr
Mar 31, 2:13 PM PDT	Lake Wind Advisory	REV	30 hr
Apr 2, 12:23 PM PDT	Winter Storm Watch	REV	27 hr
Apr 3, 3:32 PM PDT	Winter Storm Warning	REV	68 hr
Apr 5, 9:49 AM PDT	Winter Weather Advisory	REV	26 hr
Apr 5, 10:56 AM PDT	Areal Flood Warning	STO	3 hr
Apr 5, 10:58 AM PDT	Areal Flood Warning	STO	3 hr
Apr 5, 11:53 AM PDT	Areal Flood Warning	STO	6 hr
Apr 5, 3:23 PM PDT	Mesoscale Discussion	SPC	6 hr
Apr 8, 2:05 AM PDT	Lake Wind Advisory	REV	18 hr
Apr 29, 6:02 AM PDT	Lake Wind Advisory	REV	38 hr
May 2, 8:42 PM PDT	Lake Wind Advisory	REV	23 hr
May 9, 3:04 PM PDT	Lake Wind Advisory	REV	3 days
May 15, 6:58 AM PDT	Wind Advisory	REV	61 hr
May 17, 10:59 AM PDT	Winter Weather Advisory	REV	23 hr
May 18, 2:11 PM PDT	Special Weather Statement	STO	64 min
May 18, 3:12 PM PDT	Special Weather Statement	STO	63 min
May 18, 7:41 PM PDT	Special Weather Statement	STO	49 min
May 20, 2:56 AM PDT	Lake Wind Advisory	REV	41 hr
May 29, 2:02 PM PDT	Lake Wind Advisory	REV	30 hr
May 30, 5:51 AM PDT	Special Weather Statement	STO	54 min
May 30, 4:20 PM PDT	Special Weather Statement	STO	55 min
Jun 4, 1:42 PM PDT	Lake Wind Advisory	REV	30 hr
Jun 5, 1:15 PM PDT	Lake Wind Advisory	REV	34 hr
Jun 11, 10:59 AM PDT	Lake Wind Advisory	REV	35 hr
Jun 14, 2:42 PM PDT	Lake Wind Advisory	REV	31 hr
Jun 15, 2:56 PM PDT	Lake Wind Advisory	REV	30 hr
Jun 26, 2:06 PM PDT	Lake Wind Advisory	REV	54 hr
Jul 4, 9:26 AM PDT	Fire Weather Watch	REV	23 hr
Jul 5, 2:58 AM PDT	Red Flag Warning	REV	42 hr
Jul 5, 1:20 PM PDT	Lake Wind Advisory	REV	32 hr
Jul 13, 1:48 PM PDT	Fire Weather Watch	REV	38 hr
Jul 13, 1:48 PM PDT	Fire Weather Watch	REV	62 hr
Jul 20, 1:53 PM PDT	Fire Weather Watch	REV	24 hr
Jul 20, 1:53 PM PDT	Red Flag Warning	REV	55 hr
Jul 20, 3:40 PM PDT	Severe Thunderstorm Warning	REV	35 min
Jul 20, 4:43 PM PDT	Severe Thunderstorm Warning	REV	32 min
Jul 20, 5:15 PM PDT	Severe Thunderstorm Warning	REV	30 min
Jul 22, 3:58 PM PDT	Severe Thunderstorm Warning	REV	32 min
Jul 22, 4:31 PM PDT	Flash Flood Warning	REV	116 min
Jul 25, 5:37 AM PDT	Fire Weather Watch	REV	24 hr
Jul 26, 6:06 AM PDT	Red Flag Warning	REV	39 hr
Jul 27, 5:28 PM PDT	Areal Flood Advisory	REV	2 hr
Aug 10, 3:32 PM PDT	Flash Flood Warning	REV	3 hr
Aug 16, 3:42 AM PDT	Red Flag Warning	REV	25 hr
Aug 16, 10:47 AM PDT	Dense Smoke Advisory	REV	53 hr
Aug 19, 10:28 AM PDT	Dense Smoke Advisory	REV	4 days
Aug 21, 10:36 AM PDT	Fire Weather Watch	REV	59 hr
Aug 22, 6:25 PM PDT	Red Flag Warning	REV	41 hr
Aug 25, 6:10 AM PDT	Red Flag Warning	REV	14 hr
Aug 27, 9:52 PM PDT	Dense Smoke Advisory	REV	63 hr
Sep 3, 11:29 AM PDT	Heat Advisory	REV	3 days
Sep 5, 1:44 PM PDT	Fire Weather Watch	REV	42 hr
Sep 6, 8:14 AM PDT	Red Flag Warning	REV	60 hr
Sep 6, 12:01 PM PDT	Lake Wind Advisory	REV	56 hr
Sep 10, 2:06 AM PDT	Dense Smoke Advisory	REV	3 days
Sep 13, 11:34 AM PDT	Dense Smoke Advisory	REV	23 hr
Sep 14, 2:18 PM PDT	Dense Smoke Advisory	REV	4 days
Sep 15, 11:34 AM PDT	Fire Weather Watch	REV	28 hr
Sep 16, 2:29 PM PDT	Lake Wind Advisory	REV	30 hr
Sep 16, 3:12 PM PDT	Red Flag Warning	REV	53 hr
Sep 17, 9:56 PM PDT	Lake Wind Advisory	REV	22 hr
Oct 8, 12:24 PM PDT	Fire Weather Watch	REV	23 hr
Oct 8, 1:32 PM PDT	Lake Wind Advisory	REV	59 hr
Oct 9, 11:26 AM PDT	Red Flag Warning	REV	33 hr
Oct 22, 2:35 PM PDT	Fire Weather Watch	REV	24 hr
Oct 23, 2:24 PM PDT	Red Flag Warning	REV	4 days
Oct 24, 2:31 PM PDT	Lake Wind Advisory	REV	59 hr
Nov 3, 2:07 PM PST	Fire Weather Watch	REV	24 hr
Nov 4, 1:40 PM PST	Red Flag Warning	REV	50 hr
Nov 4, 1:43 PM PST	Lake Wind Advisory	REV	52 hr
Nov 6, 3:26 AM PST	Winter Weather Advisory	REV	57 hr
Nov 8, 12:09 PM PST	Snow Squall Warning	REV	66 min
Nov 11, 1:15 PM PST	Wind Advisory	REV	60 hr
Nov 12, 2:31 AM PST	High Wind Warning	REV	46 hr
Nov 15, 11:31 AM PST	High Wind Watch	REV	24 hr
Nov 15, 11:49 AM PST	Winter Storm Watch	REV	27 hr
Nov 16, 11:02 AM PST	High Wind Warning	REV	41 hr
Nov 16, 3:02 PM PST	Winter Storm Warning	REV	51 hr
Nov 18, 3:31 PM PST	Special Weather Statement	STO	44 min
Nov 25, 2:32 AM PST	Lake Wind Advisory	REV	40 hr
Dec 5, 1:47 PM PST	Lake Wind Advisory	REV	50 hr
Dec 11, 4:38 AM PST	Winter Weather Advisory	REV	23 hr
Dec 12, 8:19 AM PST	Winter Weather Advisory	REV	42 hr
Dec 14, 12:56 PM PST	Winter Storm Watch	REV	21 hr
Dec 15, 9:48 AM PST	Winter Weather Advisory	REV	50 hr
Dec 22, 1:03 PM PST	Winter Storm Watch	REV	37 hr
Dec 24, 2:00 AM PST	Winter Weather Advisory	REV	56 hr
Dec 30, 12:09 PM PST	Lake Wind Advisory	REV	17 hr

By product

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

Product	Alerts
Severe storms
Severe Thunderstorm Warning	4
Mesoscale Discussion	3
Special Weather Statement	6
Flooding
Areal Flood Warning	3
Flash Flood Warning	2
Areal Flood Advisory	1
Winter
Snow Squall Warning	1
Winter Storm Warning	4
Winter Storm Watch	6
Winter Weather Advisory	14
Heat
Heat Advisory	1
Wind and dust
High Wind Warning	2
High Wind Watch	2
Lake Wind Advisory	39
Wind Advisory	5
Fire
Red Flag Warning	11
Fire Weather Watch	11
Fog and smoke
Dense Smoke Advisory	6

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2019 2021

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.