Alert archive / California / Placer County

Weather alerts in Placer County, California, 2015

100 weather alerts in 2015, 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 2015. Tap one for its archive.

Alerts: 100
Warnings: 25
Watches: 16
Advisories: 51
Busiest month: December16 alerts
Busiest day: July 21, 20156 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, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning
Tornado warnings	0			0
Severe thunderstorm warnings	10	1	90%	1	0%
Flash flood warnings	2	0	100%	0

Each office's whole area, 2015

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Sacramento, CA: tornado warnings	6	0	100%	9	0%
NWS Sacramento, CA: severe thunderstorm warnings	21	3	86%	13	38%	10 min
NWS Sacramento, CA: flash flood warnings	5	1	80%	7	29%	114 min
NWS Reno, NV: tornado warnings	0			3	0%
NWS Reno, NV: severe thunderstorm warnings	45	6	87%	26	38%	11 min
NWS Reno, NV: flash flood warnings	54	13	76%	31	58%	66 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
Feb 4, 2:32 AM PST	High Wind Watch	REV	37 hr
Feb 4, 2:32 AM PST	Wind Advisory	REV	49 hr
Feb 4, 3:23 PM PST	Lake Wind Advisory	REV	37 hr
Feb 5, 4:06 AM PST	High Wind Warning	REV	48 hr
Feb 6, 5:11 PM PST	Winter Storm Warning	REV	11 hr
Feb 7, 3:49 AM PST	Lake Wind Advisory	REV	16 hr
Feb 7, 3:25 PM PST	Winter Weather Advisory	REV	44 hr
Feb 7, 7:25 PM PST	Lake Wind Advisory	REV	48 hr
Feb 21, 3:05 PM PST	Lake Wind Advisory	REV	24 hr
Feb 26, 12:42 PM PST	Winter Weather Advisory	REV	55 hr
Mar 14, 2:48 AM PDT	Lake Wind Advisory	REV	40 hr
Mar 14, 8:14 PM PDT	Wind Advisory	REV	23 hr
Mar 22, 2:25 AM PDT	Lake Wind Advisory	REV	41 hr
Mar 30, 2:47 PM PDT	Lake Wind Advisory	REV	31 hr
Apr 4, 2:01 AM PDT	Lake Wind Advisory	REV	21 hr
Apr 4, 1:49 PM PDT	Lake Wind Advisory	REV	33 hr
Apr 6, 2:28 AM PDT	Winter Weather Advisory	REV	49 hr
Apr 7, 2:00 PM PDT	Severe Thunderstorm Warning	STO	26 min
Apr 7, 2:25 PM PDT	Severe Thunderstorm Warning	STO	65 min
Apr 12, 11:38 AM PDT	Lake Wind Advisory	REV	53 hr
Apr 13, 2:47 AM PDT	Wind Advisory	REV	32 hr
Apr 22, 12:49 PM PDT	Special Weather Statement	STO	56 min
Apr 23, 2:19 PM PDT	Lake Wind Advisory	REV	30 hr
Apr 24, 2:45 AM PDT	Winter Weather Advisory	REV	33 hr
May 10, 2:13 PM PDT	Lake Wind Advisory	REV	30 hr
May 11, 4:57 PM PDT	Lake Wind Advisory	REV	27 hr
May 13, 1:05 PM PDT	Winter Weather Advisory	REV	41 hr
May 30, 2:36 PM PDT	Lake Wind Advisory	REV	31 hr
May 31, 3:34 PM PDT	Lake Wind Advisory	REV	28 hr
Jun 5, 2:38 PM PDT	Special Weather Statement	STO	52 min
Jun 6, 3:12 PM PDT	Severe Thunderstorm Warning	STO	33 min
Jun 6, 3:49 PM PDT	Special Weather Statement	STO	41 min
Jun 6, 4:40 PM PDT	Special Weather Statement	STO	50 min
Jun 9, 1:29 PM PDT	Flash Flood Watch	REV	33 hr
Jun 19, 2:46 AM PDT	Fire Weather Watch	REV	24 hr
Jun 20, 3:04 AM PDT	Red Flag Warning	REV	43 hr
Jun 20, 10:02 AM PDT	Lake Wind Advisory	REV	31 hr
Jun 21, 5:12 PM PDT	Dense Smoke Advisory	REV	9 hr
Jun 24, 2:47 PM PDT	Fire Weather Watch	REV	4 days
Jun 25, 1:32 PM PDT	Red Flag Warning	REV	65 hr
Jun 27, 5:38 PM PDT	Severe Thunderstorm Warning	REV	37 min
Jul 4, 2:38 AM PDT	Flash Flood Watch	REV	16 hr
Jul 6, 3:20 AM PDT	Flash Flood Watch	REV	18 hr
Jul 6, 9:32 PM PDT	Flash Flood Watch	REV	21 hr
Jul 7, 10:04 PM PDT	Flash Flood Watch	REV	23 hr
Jul 8, 12:41 PM PDT	Severe Thunderstorm Warning	REV	49 min
Jul 9, 11:52 AM PDT	Mesoscale Discussion	SPC	113 min
Jul 9, 12:50 PM PDT	Severe Thunderstorm Warning	REV	25 min
Jul 16, 3:59 PM PDT	Severe Thunderstorm Warning	REV	46 min
Jul 20, 6:25 PM PDT	Special Weather Statement	STO	50 min
Jul 21, 6:16 AM PDT	Flash Flood Watch	REV	12 hr
Jul 21, 1:12 PM PDT	Severe Thunderstorm Warning	REV	48 min
Jul 21, 1:42 PM PDT	Flash Flood Warning	REV	3 hr
Jul 21, 1:58 PM PDT	Severe Thunderstorm Warning	REV	47 min
Jul 21, 3:46 PM PDT	Severe Thunderstorm Warning	REV	44 min
Jul 21, 6:09 PM PDT	Areal Flood Warning	STO	3 hr
Aug 5, 10:28 AM PDT	Fire Weather Watch	REV	43 hr
Aug 11, 9:43 AM PDT	Fire Weather Watch	REV	24 hr
Aug 12, 9:23 AM PDT	Red Flag Warning	REV	59 hr
Aug 12, 12:08 PM PDT	Lake Wind Advisory	REV	56 hr
Aug 27, 2:00 PM PDT	Fire Weather Watch	REV	14 hr
Aug 28, 4:00 AM PDT	Lake Wind Advisory	REV	47 hr
Aug 28, 4:00 AM PDT	Wind Advisory	REV	38 hr
Aug 28, 4:07 AM PDT	Red Flag Warning	REV	41 hr
Sep 1, 9:55 AM PDT	Red Flag Warning	REV	35 hr
Sep 1, 3:07 PM PDT	Lake Wind Advisory	REV	30 hr
Sep 3, 1:22 PM PDT	Lake Wind Advisory	REV	32 hr
Sep 13, 2:34 PM PDT	Lake Wind Advisory	REV	3 days
Oct 4, 12:32 AM PDT	Lake Wind Advisory	REV	14 hr
Oct 9, 3:05 PM PDT	Lake Wind Advisory	REV	29 hr
Oct 17, 7:05 AM PDT	Flash Flood Warning	STO	4 hr
Oct 24, 3:13 AM PDT	Lake Wind Advisory	REV	41 hr
Oct 30, 2:45 PM PDT	Lake Wind Advisory	REV	56 hr
Oct 31, 2:33 PM PDT	Winter Weather Advisory	REV	56 hr
Nov 7, 1:26 PM PST	Lake Wind Advisory	REV	33 hr
Nov 8, 1:36 PM PST	Flash Flood Watch	STO	31 hr
Nov 8, 1:47 PM PST	Winter Weather Advisory	REV	44 hr
Nov 13, 12:43 PM PST	Lake Wind Advisory	REV	39 hr
Nov 13, 12:43 PM PST	Winter Weather Advisory	REV	60 hr
Nov 22, 2:48 PM PST	Winter Storm Watch	REV	21 hr
Nov 22, 2:55 PM PST	Lake Wind Advisory	REV	46 hr
Nov 22, 2:55 PM PST	Wind Advisory	REV	49 hr
Nov 23, 3:36 AM PST	Winter Weather Advisory	REV	56 hr
Nov 23, 11:49 AM PST	Winter Storm Warning	REV	33 hr
Dec 1, 1:53 PM PST	Winter Weather Advisory	REV	56 hr
Dec 5, 2:21 PM PST	Lake Wind Advisory	REV	26 hr
Dec 7, 2:52 PM PST	Winter Storm Watch	REV	25 hr
Dec 8, 3:28 PM PST	Winter Storm Warning	REV	67 hr
Dec 8, 3:29 PM PST	Lake Wind Advisory	REV	37 hr
Dec 10, 6:25 PM PST	Special Weather Statement	STO	35 min
Dec 11, 2:23 PM PST	Winter Storm Warning	REV	56 hr
Dec 13, 9:41 AM PST	Areal Flood Advisory	STO	3 hr
Dec 13, 1:11 PM PST	Mesoscale Discussion	SPC	5 hr
Dec 17, 2:06 PM PST	Winter Weather Advisory	REV	46 hr
Dec 19, 3:05 PM PST	Lake Wind Advisory	REV	31 hr
Dec 20, 3:25 PM PST	Winter Storm Warning	REV	42 hr
Dec 21, 8:56 AM PST	Flash Flood Watch	STO	23 hr
Dec 22, 2:37 AM PST	Lake Wind Advisory	REV	19 hr
Dec 22, 1:52 PM PST	Winter Storm Warning	REV	61 hr
Dec 24, 12:24 PM PST	Lake Wind Advisory	REV	46 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	10
Mesoscale Discussion	2
Special Weather Statement	6
Flooding
Areal Flood Warning	1
Flash Flood Warning	2
Flash Flood Watch	8
Areal Flood Advisory	1
Winter
Winter Storm Warning	6
Winter Storm Watch	2
Winter Weather Advisory	11
Wind and dust
High Wind Warning	1
High Wind Watch	1
Lake Wind Advisory	33
Wind Advisory	5
Fire
Red Flag Warning	5
Fire Weather Watch	5
Fog and smoke
Dense Smoke Advisory	1

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2014 2016

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.