Alert archive / California / Placer County

Weather alerts in Placer County, California, 2011

142 weather alerts in 2011, 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 2011. Tap one for its archive.

Alerts: 142
Warnings: 11
Watches: 11
Advisories: 110
Busiest month: March36 alerts
Busiest day: March 19, 20115 alerts

Over time

By month

Warning verification

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

0 of 2 tornado warnings covering Placer County in 2011 had a tornado report inside them.

Placer County, 2011

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	2	0	100%	0
Severe thunderstorm warnings	0			2	0%
Flash flood warnings	1	1	0%	1	100%	36 min

Each office's whole area, 2011

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Reno, NV: tornado warnings	1	0	100%	1	0%
NWS Reno, NV: severe thunderstorm warnings	8	0	100%	6	0%
NWS Reno, NV: flash flood warnings	9	2	78%	8	38%	66 min
NWS Sacramento, CA: tornado warnings	10	4	60%	16	44%	19 min
NWS Sacramento, CA: severe thunderstorm warnings	18	3	83%	7	57%	19 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
Dec 31, 9:28 PM PST	Winter Weather Advisory	REV	13 hr
Jan 1, 2:18 PM PST	Winter Weather Advisory	REV	31 hr
Jan 3, 3:59 AM PST	Lake Wind Advisory	REV	27 hr
Jan 9, 2:58 PM PST	Lake Wind Advisory	REV	16 hr
Jan 19, 2:49 AM PST	Lake Wind Advisory	REV	31 hr
Jan 22, 9:56 AM PST	Lake Wind Advisory	REV	17 hr
Jan 28, 9:46 PM PST	Lake Wind Advisory	REV	30 hr
Jan 30, 3:23 AM PST	Winter Weather Advisory	REV	10 hr
Jan 31, 3:25 PM PST	Lake Wind Advisory	REV	43 hr
Feb 5, 3:42 AM PST	Lake Wind Advisory	REV	24 hr
Feb 6, 2:03 PM PST	Lake Wind Advisory	REV	32 hr
Feb 8, 3:40 AM PST	Lake Wind Advisory	REV	24 hr
Feb 12, 3:04 AM PST	Lake Wind Advisory	REV	24 hr
Feb 12, 3:13 PM PST	High Wind Watch	REV	24 hr
Feb 13, 3:29 PM PST	High Wind Warning	REV	61 hr
Feb 13, 3:29 PM PST	Wind Advisory	REV	12 hr
Feb 13, 3:29 PM PST	Winter Storm Watch	REV	48 hr
Feb 14, 3:14 PM PST	Winter Storm Warning	REV	55 hr
Feb 15, 5:17 PM PST	Mesoscale Discussion	SPC	6 hr
Feb 16, 4:24 AM PST	Winter Storm Watch	REV	18 hr
Feb 16, 10:13 PM PST	Winter Storm Warning	REV	59 hr
Feb 17, 3:29 AM PST	Lake Wind Advisory	REV	7 hr
Feb 22, 3:15 PM PST	Winter Storm Watch	REV	24 hr
Feb 23, 1:56 PM PST	Lake Wind Advisory	REV	26 hr
Feb 23, 3:25 PM PST	Winter Storm Warning	REV	60 hr
Feb 24, 5:15 PM PST	Mesoscale Discussion	SPC	6 hr
Feb 25, 12:25 AM PST	Mesoscale Discussion	SPC	6 hr
Feb 25, 10:19 AM PST	Mesoscale Discussion	SPC	4 hr
Feb 27, 2:09 PM PST	Lake Wind Advisory	REV	29 hr
Mar 1, 4:20 AM PST	Winter Weather Advisory	REV	28 hr
Mar 5, 3:39 AM PST	Lake Wind Advisory	REV	5 hr
Mar 5, 3:22 PM PST	Winter Weather Advisory	REV	19 hr
Mar 6, 4:08 AM PST	Winter Weather Advisory	REV	24 hr
Mar 7, 7:04 AM PST	Lake Wind Advisory	REV	11 hr
Mar 9, 2:49 PM PST	Lake Wind Advisory	REV	30 hr
Mar 11, 2:24 PM PST	Lake Wind Advisory	REV	29 hr
Mar 12, 1:38 PM PST	Lake Wind Advisory	REV	29 hr
Mar 13, 3:18 AM PDT	Winter Weather Advisory	REV	27 hr
Mar 14, 12:57 AM PDT	Areal Flood Advisory	STO	5 hr
Mar 14, 3:22 PM PDT	Lake Wind Advisory	REV	28 hr
Mar 14, 3:22 PM PDT	Wind Advisory	REV	37 hr
Mar 15, 4:20 AM PDT	Winter Weather Advisory	REV	35 hr
Mar 15, 7:56 PM PDT	Areal Flood Advisory	STO	6 hr
Mar 16, 3:25 AM PDT	Areal Flood Advisory	STO	18 hr
Mar 17, 3:54 AM PDT	Winter Storm Watch	REV	11 hr
Mar 17, 3:15 PM PDT	Lake Wind Advisory	REV	25 hr
Mar 17, 3:16 PM PDT	Winter Storm Warning	REV	41 hr
Mar 18, 9:26 AM PDT	Mesoscale Discussion	SPC	4 hr
Mar 18, 11:25 AM PDT	Areal Flood Advisory	STO	19 hr
Mar 19, 4:06 AM PDT	Winter Storm Watch	REV	13 hr
Mar 19, 5:05 AM PDT	Lake Wind Advisory	REV	3 hr
Mar 19, 8:10 AM PDT	Lake Wind Advisory	REV	20 hr
Mar 19, 8:17 AM PDT	Winter Weather Advisory	REV	4 hr
Mar 19, 3:17 PM PDT	Winter Storm Warning	REV	37 hr
Mar 20, 12:16 AM PDT	Areal Flood Advisory	STO	18 hr
Mar 21, 3:07 PM PDT	Winter Storm Watch	REV	21 hr
Mar 21, 5:16 PM PDT	Special Weather Statement	STO	59 min
Mar 21, 5:25 PM PDT	Special Weather Statement	STO	50 min
Mar 22, 11:54 AM PDT	Winter Storm Watch	REV	28 hr
Mar 22, 11:54 AM PDT	Winter Storm Warning	REV	71 hr
Mar 24, 7:57 AM PDT	Areal Flood Advisory	STO	30 hr
Mar 24, 9:58 AM PDT	Mesoscale Discussion	SPC	4 hr
Mar 25, 4:31 AM PDT	Lake Wind Advisory	REV	15 hr
Mar 25, 4:38 AM PDT	Winter Weather Advisory	REV	35 hr
Mar 26, 3:59 PM PDT	Lake Wind Advisory	REV	28 hr
Apr 1, 2:42 PM PDT	Lake Wind Advisory	REV	29 hr
Apr 4, 2:06 PM PDT	Lake Wind Advisory	REV	30 hr
Apr 5, 7:50 PM PDT	Lake Wind Advisory	REV	27 hr
Apr 6, 5:00 AM PDT	Winter Weather Advisory	REV	33 hr
Apr 12, 2:40 PM PDT	Lake Wind Advisory	REV	29 hr
Apr 15, 2:54 AM PDT	Lake Wind Advisory	REV	17 hr
Apr 16, 3:16 PM PDT	Lake Wind Advisory	REV	53 hr
Apr 19, 2:20 PM PDT	Lake Wind Advisory	REV	49 hr
Apr 23, 3:44 PM PDT	Lake Wind Advisory	REV	40 hr
Apr 24, 3:26 PM PDT	Wind Advisory	REV	29 hr
Apr 27, 2:54 PM PDT	Lake Wind Advisory	REV	36 hr
Apr 29, 3:11 AM PDT	Lake Wind Advisory	REV	32 hr
May 1, 2:09 PM PDT	Lake Wind Advisory	REV	30 hr
May 6, 3:48 PM PDT	Lake Wind Advisory	REV	35 hr
May 8, 3:05 PM PDT	Winter Weather Advisory	REV	16 hr
May 13, 2:17 PM PDT	Lake Wind Advisory	REV	33 hr
May 14, 2:55 AM PDT	Winter Weather Advisory	REV	31 hr
May 14, 2:54 PM PDT	Lake Wind Advisory	REV	28 hr
May 15, 2:29 PM PDT	Areal Flood Advisory	STO	3 hr
May 15, 3:16 PM PDT	Winter Weather Advisory	REV	36 hr
May 17, 3:29 AM PDT	Winter Weather Advisory	REV	27 hr
May 23, 2:41 AM PDT	Lake Wind Advisory	REV	17 hr
May 24, 2:47 PM PDT	Wind Advisory	REV	32 hr
May 26, 3:44 AM PDT	Lake Wind Advisory	REV	16 hr
May 26, 4:22 PM PDT	Lake Wind Advisory	REV	28 hr
May 27, 2:29 PM PDT	Lake Wind Advisory	REV	30 hr
May 28, 4:01 AM PDT	Winter Weather Advisory	REV	23 hr
May 30, 2:15 PM PDT	Lake Wind Advisory	REV	30 hr
May 31, 7:57 PM PDT	Lake Wind Advisory	REV	25 hr
Jun 1, 6:04 PM PDT	Tornado Warning	STO	41 min
Jun 20, 11:30 AM PDT	Areal Flood Advisory	REV	4 days
Jun 22, 3:43 PM PDT	Lake Wind Advisory	REV	29 hr
Jun 27, 3:41 PM PDT	Lake Wind Advisory	REV	31 hr
Jun 28, 3:10 PM PDT	Areal Flood Advisory	REV	39 hr
Jul 6, 2:05 PM PDT	Lake Wind Advisory	REV	30 hr
Jul 10, 2:06 PM PDT	Lake Wind Advisory	REV	31 hr
Jul 11, 3:45 PM PDT	Lake Wind Advisory	REV	29 hr
Jul 12, 9:09 PM PDT	Lake Wind Advisory	REV	24 hr
Jul 17, 2:42 PM PDT	Lake Wind Advisory	REV	48 hr
Jul 24, 2:50 PM PDT	Lake Wind Advisory	REV	30 hr
Aug 13, 2:35 PM PDT	Lake Wind Advisory	REV	29 hr
Sep 8, 10:36 AM PDT	Lake Wind Advisory	REV	24 hr
Sep 11, 4:54 PM PDT	Flash Flood Warning	REV	109 min
Sep 12, 3:58 AM PDT	Flash Flood Watch	REV	18 hr
Sep 12, 2:43 PM PDT	Special Weather Statement	STO	32 min
Sep 13, 1:53 AM PDT	Flash Flood Watch	REV	20 hr
Sep 13, 6:10 PM PDT	Special Weather Statement	STO	50 min
Sep 24, 1:59 PM PDT	Lake Wind Advisory	REV	30 hr
Sep 30, 3:20 PM PDT	Lake Wind Advisory	REV	29 hr
Oct 2, 3:48 AM PDT	Lake Wind Advisory	REV	19 hr
Oct 2, 3:07 PM PDT	Winter Storm Watch	REV	25 hr
Oct 2, 3:11 PM PDT	Lake Wind Advisory	REV	37 hr
Oct 3, 3:52 PM PDT	Winter Storm Warning	REV	43 hr
Oct 4, 3:55 AM PDT	Lake Wind Advisory	REV	19 hr
Oct 5, 3:18 AM PDT	Lake Wind Advisory	REV	17 hr
Oct 10, 11:08 AM PDT	Lake Wind Advisory	REV	10 hr
Oct 11, 3:13 AM PDT	Lake Wind Advisory	REV	8 hr
Oct 23, 2:32 PM PDT	Lake Wind Advisory	REV	30 hr
Oct 25, 2:49 PM PDT	Lake Wind Advisory	REV	24 hr
Oct 31, 2:54 PM PDT	Lake Wind Advisory	REV	29 hr
Nov 2, 3:39 PM PDT	Wind Advisory	REV	31 hr
Nov 2, 3:40 PM PDT	Winter Weather Advisory	REV	36 hr
Nov 4, 2:56 PM PDT	Winter Weather Advisory	REV	42 hr
Nov 16, 3:13 PM PST	Lake Wind Advisory	REV	21 hr
Nov 17, 12:14 PM PST	Wind Advisory	REV	28 hr
Nov 18, 3:51 PM PST	Lake Wind Advisory	REV	5 hr
Nov 20, 8:25 AM PST	Winter Weather Advisory	REV	8 hr
Nov 22, 3:23 AM PST	Lake Wind Advisory	REV	13 hr
Nov 22, 2:57 PM PST	Lake Wind Advisory	REV	31 hr
Nov 29, 2:55 PM PST	Lake Wind Advisory	REV	4 days
Nov 29, 2:55 PM PST	Wind Advisory	REV	56 hr
Dec 1, 4:28 PM PST	High Wind Warning	REV	7 hr
Dec 4, 2:59 AM PST	Lake Wind Advisory	REV	35 hr
Dec 15, 2:36 AM PST	Lake Wind Advisory	REV	49 hr
Dec 18, 3:11 PM PST	Lake Wind Advisory	REV	43 hr
Dec 21, 2:50 AM PST	Lake Wind Advisory	REV	36 hr
Dec 29, 3:22 PM PST	Lake Wind Advisory	REV	28 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
Tornado Warning	1
Mesoscale Discussion	6
Special Weather Statement	4
Flooding
Flash Flood Warning	1
Flash Flood Watch	2
Areal Flood Advisory	9
Winter
Winter Storm Warning	7
Winter Storm Watch	8
Winter Weather Advisory	19
Wind and dust
High Wind Warning	2
High Wind Watch	1
Lake Wind Advisory	75
Wind Advisory	7

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2010 2012

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.