Alert archive / California / Los Angeles County

Weather alerts in Los Angeles County, California, 2021

125 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Los Angeles County and its neighbors

Each county as a circle sized by its count in 2021. Tap one for its archive.

Alerts: 125
Warnings: 15
Watches: 17
Advisories: 81
Busiest month: January25 alerts
Busiest day: January 9, 20213 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 reports fell inside a warning.

Los Angeles County, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning
Tornado warnings	0			2	0%
Severe thunderstorm warnings	0			1	0%
Flash flood warnings	1	0	100%	4	0%

Each office's whole area, 2021

	Warnings	With a report	False alarm ratio	Reports	Inside a warning
NWS Los Angeles, CA: tornado warnings	0			2	0%
NWS Los Angeles, CA: severe thunderstorm warnings	0			4	0%
NWS Los Angeles, CA: flash flood warnings	5	0	100%	9	0%

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, 4:47 AM PST	Dense Fog Advisory	LOX	4 hr
Jan 8, 2:02 PM PST	Wind Advisory	LOX	66 hr
Jan 8, 7:26 PM PST	High Wind Warning	LOX	19 hr
Jan 8, 7:26 PM PST	Wind Advisory	LOX	11 hr
Jan 8, 11:08 PM PST	High Wind Warning	LOX	4 hr
Jan 10, 2:18 AM PST	Coastal Flood Advisory	LOX	33 hr
Jan 12, 2:24 AM PST	Beach Hazards Statement	LOX	43 hr
Jan 13, 2:11 PM PST	Wind Advisory	LOX	49 hr
Jan 13, 2:45 PM PST	Red Flag Warning	LOX	3 days
Jan 15, 4:05 AM PST	High Surf Advisory	LOX	5 days
Jan 15, 8:42 PM PST	Wind Advisory	LOX	42 hr
Jan 16, 6:42 PM PST	High Wind Watch	LOX	33 hr
Jan 17, 2:39 PM PST	Fire Weather Watch	LOX	21 hr
Jan 18, 3:23 AM PST	High Wind Warning	LOX	48 hr
Jan 18, 11:40 AM PST	Red Flag Warning	LOX	46 hr
Jan 18, 2:01 PM PST	Wind Advisory	LOX	52 hr
Jan 19, 1:41 PM PST	Wind Advisory	LOX	28 hr
Jan 20, 6:06 PM PST	Wind Advisory	LOX	4 hr
Jan 23, 9:28 PM PST	High Surf Advisory	LOX	6 days
Jan 24, 8:13 PM PST	Freeze Watch	LOX	18 hr
Jan 24, 8:13 PM PST	Wind Advisory	LOX	37 hr
Jan 25, 2:29 PM PST	Frost Advisory	LOX	19 hr
Jan 26, 2:21 PM PST	Flash Flood Watch	LOX	62 hr
Jan 28, 6:41 PM PST	Areal Flood Advisory	LOX	4 hr
Jan 28, 8:11 PM PST	Areal Flood Advisory	LOX	5 hr
Feb 3, 2:06 PM PST	Wind Advisory	LOX	25 hr
Feb 5, 9:55 PM PST	Wind Advisory	LOX	13 hr
Feb 7, 10:14 PM PST	Dense Fog Advisory	LOX	11 hr
Feb 12, 5:33 AM PST	Wind Advisory	LOX	3 days
Feb 14, 9:53 PM PST	Wind Advisory	LOX	53 hr
Feb 17, 1:30 PM PST	Wind Advisory	LOX	25 hr
Feb 19, 2:17 PM PST	Wind Advisory	LOX	3 days
Feb 23, 12:01 PM PST	High Wind Watch	LOX	15 hr
Feb 24, 3:23 AM PST	High Wind Warning	LOX	33 hr
Feb 24, 3:23 AM PST	Wind Advisory	LOX	39 hr
Feb 25, 9:02 PM PST	Wind Advisory	LOX	69 hr
Feb 26, 3:13 AM PST	High Wind Watch	LOX	24 hr
Feb 27, 3:30 AM PST	High Wind Warning	LOX	33 hr
Mar 10, 2:34 AM PST	Areal Flood Advisory	LOX	88 min
Mar 10, 2:46 PM PST	Special Weather Statement	LOX	59 min
Mar 14, 12:42 PM PDT	Wind Advisory	LOX	38 hr
Mar 22, 3:27 AM PDT	Wind Advisory	LOX	57 hr
Mar 23, 3:29 AM PDT	Wind Advisory	LOX	33 hr
Mar 29, 2:24 PM PDT	Wind Advisory	LOX	49 hr
Mar 30, 9:28 AM PDT	Wind Advisory	LOX	30 hr
Apr 7, 2:49 AM PDT	Wind Advisory	LOX	51 hr
Apr 10, 2:20 AM PDT	Wind Advisory	LOX	25 hr
Apr 17, 7:26 PM PDT	Wind Advisory	LOX	19 hr
Apr 22, 12:59 PM PDT	Beach Hazards Statement	LOX	68 hr
Apr 29, 10:59 AM PDT	Beach Hazards Statement	LOX	4 days
Apr 30, 8:07 PM PDT	Wind Advisory	LOX	55 hr
May 18, 1:43 PM PDT	Beach Hazards Statement	LOX	5 days
May 23, 11:07 AM PDT	Beach Hazards Statement	LOX	10 hr
Jun 11, 2:03 PM PDT	Excessive Heat Watch	LOX	5 days
Jun 13, 6:06 PM PDT	Excessive Heat Warning	LOX	7 days
Jun 16, 2:47 AM PDT	Heat Advisory	LOX	42 hr
Jun 17, 9:05 PM PDT	Heat Advisory	LOX	48 hr
Jun 24, 1:59 PM PDT	Excessive Heat Watch	LOX	24 hr
Jun 25, 1:34 PM PDT	Excessive Heat Warning	LOX	3 days
Jun 25, 1:34 PM PDT	Heat Advisory	LOX	3 days
Jul 8, 2:18 PM PDT	Heat Advisory	LOX	4 days
Jul 26, 1:45 AM PDT	Flash Flood Watch	LOX	17 hr
Aug 2, 2:28 AM PDT	Heat Advisory	LOX	66 hr
Aug 13, 10:59 AM PDT	Heat Advisory	LOX	3 days
Aug 18, 10:02 PM PDT	Beach Hazards Statement	LOX	3 days
Aug 27, 3:25 AM PDT	Heat Advisory	LOX	4 days
Sep 3, 2:00 AM PDT	Beach Hazards Statement	LOX	4 days
Sep 4, 1:48 PM PDT	Heat Advisory	LOX	6 days
Sep 5, 8:10 PM PDT	Heat Advisory	LOX	24 hr
Sep 9, 5:07 PM PDT	Areal Flood Advisory	LOX	3 hr
Sep 10, 12:01 AM PDT	Areal Flood Advisory	LOX	18 min
Sep 10, 12:19 AM PDT	Flash Flood Warning	LOX	3 hr
Sep 11, 2:35 AM PDT	Heat Advisory	LOX	17 hr
Sep 12, 5:11 AM PDT	Beach Hazards Statement	LOX	4 days
Sep 20, 1:25 PM PDT	Heat Advisory	LOX	55 hr
Oct 4, 8:54 PM PDT	Special Weather Statement	LOX	36 min
Oct 9, 7:20 PM PDT	High Surf Advisory	LOX	64 hr
Oct 10, 9:21 PM PDT	Wind Advisory	LOX	39 hr
Oct 12, 2:26 PM PDT	Fire Weather Watch	LOX	24 hr
Oct 13, 2:11 PM PDT	Red Flag Warning	LOX	3 days
Oct 14, 11:41 AM PDT	Wind Advisory	LOX	48 hr
Oct 21, 2:28 PM PDT	Beach Hazards Statement	LOX	56 hr
Oct 23, 9:48 PM PDT	High Surf Advisory	LOX	4 days
Oct 24, 2:19 PM PDT	Wind Advisory	LOX	28 hr
Oct 25, 12:24 PM PDT	Areal Flood Advisory	LOX	4 hr
Oct 27, 2:02 PM PDT	Wind Advisory	LOX	25 hr
Nov 3, 5:41 AM PDT	Dense Fog Advisory	LOX	4 hr
Nov 3, 10:46 PM PDT	Dense Fog Advisory	LOX	10 hr
Nov 4, 1:29 PM PDT	Beach Hazards Statement	LOX	30 hr
Nov 7, 1:23 AM PST	Dense Fog Advisory	LOX	8 hr
Nov 10, 9:21 AM PST	Wind Advisory	LOX	53 hr
Nov 15, 12:30 PM PST	Dense Fog Advisory	LOX	22 hr
Nov 18, 2:26 PM PST	Fire Weather Watch	LOX	48 hr
Nov 19, 1:40 AM PST	Dense Fog Advisory	LOX	7 hr
Nov 19, 2:15 PM PST	Red Flag Warning	LOX	3 days
Nov 20, 2:50 AM PST	Dense Fog Advisory	LOX	6 hr
Nov 20, 2:50 AM PST	Wind Advisory	LOX	58 hr
Nov 21, 2:50 PM PST	Fire Weather Watch	LOX	43 hr
Nov 23, 9:34 AM PST	Red Flag Warning	LOX	3 days
Nov 23, 2:24 PM PST	High Wind Watch	LOX	24 hr
Nov 23, 2:24 PM PST	Wind Advisory	LOX	66 hr
Nov 24, 2:02 PM PST	High Wind Warning	LOX	25 hr
Nov 25, 8:49 AM PST	Wind Advisory	LOX	21 hr
Dec 1, 1:54 PM PST	Dense Fog Advisory	LOX	20 hr
Dec 5, 2:59 AM PST	Dense Fog Advisory	LOX	6 hr
Dec 10, 3:08 AM PST	Frost Advisory	LOX	29 hr
Dec 12, 12:02 PM PST	Flash Flood Watch	LOX	54 hr
Dec 12, 8:55 PM PST	Wind Advisory	LOX	54 hr
Dec 13, 12:42 PM PST	High Surf Advisory	LOX	49 hr
Dec 14, 4:09 AM PST	Areal Flood Advisory	LOX	6 hr
Dec 14, 10:12 AM PST	Areal Flood Advisory	LOX	5 hr
Dec 14, 8:26 PM PST	Frost Advisory	LOX	81 min
Dec 14, 9:47 PM PST	Frost Advisory	LOX	11 hr
Dec 14, 9:47 PM PST	Freeze Warning	LOX	11 hr
Dec 16, 2:46 AM PST	Wind Advisory	LOX	59 hr
Dec 23, 6:30 PM PST	Areal Flood Advisory	LOX	2 hr
Dec 23, 8:54 PM PST	Areal Flood Advisory	LOX	4 hr
Dec 25, 10:49 PM PST	Areal Flood Advisory	LOX	3 hr
Dec 27, 2:35 AM PST	Freeze Watch	LOX	12 hr
Dec 27, 2:13 PM PST	Frost Advisory	LOX	18 hr
Dec 29, 1:55 PM PST	Flash Flood Watch	LOX	26 hr
Dec 29, 11:02 PM PST	Areal Flood Advisory	LOX	6 hr
Dec 30, 4:54 AM PST	Areal Flood Advisory	LOX	6 hr
Dec 30, 10:47 AM PST	Areal Flood Advisory	LOX	4 hr
Dec 30, 4:07 PM PST	Flash Flood Watch	LOX	4 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
Special Weather Statement	2
Flooding
Flash Flood Warning	1
Flash Flood Watch	5
Areal Flood Advisory	14
Heat
Excessive Heat Warning	2
Excessive Heat Watch	2
Heat Advisory	11
Cold
Freeze Warning	1
Freeze Watch	2
Frost Advisory	5
Wind and dust
High Wind Warning	6
High Wind Watch	4
Wind Advisory	35
Fire
Red Flag Warning	5
Fire Weather Watch	4
Fog and smoke
Dense Fog Advisory	10
Coast and beach
Coastal Flood Advisory	1
High Surf Advisory	5
Beach Hazards Statement	10

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2020 2022

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.