Alert archive / Pennsylvania / Delaware County

Weather alerts in Delaware County, Pennsylvania, 2022

174 weather alerts in 2022, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Delaware County and its neighbors

Each county as a circle sized by its count in 2022. Tap one for its archive.

Alerts: 174
Warnings: 29
Watches: 22
Advisories: 69
Busiest month: May31 alerts
Busiest day: May 20, 20228 alerts

Over time

By month

Warning verification

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

Delaware County, 2022

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	0			0
Severe thunderstorm warnings	15	12	20%	12	83%	26 min
Flash flood warnings	2	2	0%	2	100%	60 min

Each office's whole area, 2022

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Philadelphia/Mount Holly: tornado warnings	7	0	100%	3	0%
NWS Philadelphia/Mount Holly: severe thunderstorm warnings	170	93	45%	306	90%	21 min
NWS Philadelphia/Mount Holly: flash flood warnings	19	9	53%	26	81%	45 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, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.

Issued	Product	Office	Lasted
Dec 31, 9:44 PM EST	Dense Fog Advisory	PHI	12 hr
Jan 2, 2:49 PM EST	Winter Weather Advisory	PHI	25 hr
Jan 2, 3:35 PM EST	Coastal Flood Advisory	PHI	46 hr
Jan 3, 11:06 AM EST	Mesoscale Discussion	SPC	5 hr
Jan 4, 3:00 PM EST	Winter Weather Advisory	PHI	21 hr
Jan 5, 3:06 PM EST	Winter Weather Advisory	PHI	43 hr
Jan 7, 2:02 AM EST	Mesoscale Discussion	SPC	5 hr
Jan 8, 3:51 AM EST	Winter Weather Advisory	PHI	35 hr
Jan 15, 2:58 PM EST	Winter Weather Advisory	PHI	37 hr
Jan 16, 3:16 AM EST	Coastal Flood Advisory	PHI	39 hr
Jan 17, 1:42 AM EST	Special Weather Statement	PHI	63 min
Jan 17, 3:10 AM EST	Wind Advisory	PHI	15 hr
Jan 19, 3:03 PM EST	Winter Weather Advisory	PHI	20 hr
Jan 27, 3:13 AM EST	Winter Storm Watch	PHI	24 hr
Jan 27, 3:37 PM EST	Winter Storm Warning	PHI	48 hr
Feb 2, 7:32 AM EST	Dense Fog Advisory	PHI	5 hr
Feb 2, 3:21 PM EST	Dense Fog Advisory	PHI	15 hr
Feb 3, 1:33 PM EST	Dense Fog Advisory	PHI	8 hr
Feb 7, 2:53 AM EST	Winter Weather Advisory	PHI	10 hr
Feb 12, 3:10 PM EST	Winter Weather Advisory	PHI	25 hr
Feb 17, 3:49 AM EST	Wind Advisory	PHI	30 hr
Feb 18, 6:17 AM EST	Severe Thunderstorm Warning	PHI	43 min
Feb 18, 11:54 AM EST	Wind Advisory	PHI	33 hr
Feb 19, 12:58 PM EST	Mesoscale Discussion	SPC	4 hr
Feb 19, 2:29 PM EST	Special Weather Statement	PHI	61 min
Feb 24, 3:38 AM EST	Winter Weather Advisory	PHI	33 hr
Feb 24, 9:13 PM EST	Mesoscale Discussion	SPC	5 hr
Mar 7, 2:57 AM EST	Wind Advisory	PHI	22 hr
Mar 7, 5:53 PM EST	Mesoscale Discussion	SPC	97 min
Mar 7, 6:19 PM EST	Severe Thunderstorm Watch	SPC	4 hr
Mar 7, 7:42 PM EST	Mesoscale Discussion	SPC	93 min
Mar 7, 8:21 PM EST	Severe Thunderstorm Warning	PHI	54 min
Mar 7, 9:02 PM EST	Severe Thunderstorm Warning Considerable damage threat	PHI	58 min
Mar 11, 3:19 PM EST	Wind Advisory	PHI	34 hr
Mar 11, 3:19 PM EST	Winter Weather Advisory	PHI	27 hr
Mar 18, 12:55 AM EDT	Dense Fog Advisory	PHI	10 hr
Mar 19, 8:38 PM EDT	Special Weather Statement	PHI	37 min
Mar 28, 3:42 PM EDT	Snow Squall Warning	PHI	33 min
Mar 31, 4:20 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Mar 31, 7:13 PM EDT	Mesoscale Discussion	SPC	92 min
Mar 31, 9:36 PM EDT	Severe Thunderstorm Warning	PHI	54 min
Mar 31, 9:43 PM EDT	Mesoscale Discussion	SPC	92 min
Mar 31, 10:21 PM EDT	Areal Flood Advisory	PHI	61 min
Mar 31, 10:23 PM EDT	Severe Thunderstorm Warning	PHI	25 min
Apr 7, 9:44 AM EDT	Areal Flood Advisory	PHI	3 hr
Apr 7, 12:05 PM EDT	Flood Watch	PHI	13 hr
Apr 7, 7:01 PM EDT	Areal Flood Advisory	PHI	5 hr
Apr 9, 9:34 PM EDT	Frost Advisory	PHI	35 hr
Apr 14, 2:19 PM EDT	Mesoscale Discussion	SPC	116 min
Apr 14, 4:42 PM EDT	Severe Thunderstorm Warning	PHI	48 min
Apr 16, 12:14 PM EDT	Freeze Watch	PHI	27 hr
Apr 17, 2:57 PM EDT	Frost Advisory	PHI	17 hr
Apr 18, 4:50 AM EDT	Coastal Flood Advisory	PHI	25 hr
Apr 19, 1:20 AM EDT	Areal Flood Warning	PHI	3 hr
Apr 19, 1:38 AM EDT	River Flood Warning	PHI	3 hr
Apr 19, 4:50 AM EDT	River Flood Warning	PHI	7 hr
Apr 27, 3:05 PM EDT	Fire Weather Watch	PHI	13 hr
Apr 27, 3:05 PM EDT	Fire Weather Watch	PHI	36 hr
Apr 28, 3:59 AM EDT	Red Flag Warning	PHI	18 hr
Apr 29, 3:27 AM EDT	Red Flag Warning	PHI	18 hr
May 6, 3:25 PM EDT	Wind Advisory	PHI	37 hr
May 7, 4:36 AM EDT	Coastal Flood Advisory	PHI	3 days
May 13, 3:46 PM EDT	Dense Fog Advisory	PHI	20 hr
May 16, 12:01 PM EDT	Mesoscale Discussion	SPC	119 min
May 16, 1:33 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
May 16, 5:56 PM EDT	Areal Flood Advisory	PHI	53 min
May 16, 5:59 PM EDT	Special Weather Statement	PHI	31 min
May 16, 6:28 PM EDT	Special Weather Statement	PHI	32 min
May 20, 3:15 AM EDT	Heat Advisory	PHI	59 hr
May 20, 11:35 AM EDT	Tornado Watch	SPC	7 hr
May 20, 1:49 PM EDT	Mesoscale Discussion	SPC	86 min
May 20, 2:27 PM EDT	Severe Thunderstorm Warning	PHI	48 min
May 20, 3:00 PM EDT	Severe Thunderstorm Warning	PHI	31 min
May 20, 3:36 PM EDT	Mesoscale Discussion	SPC	84 min
May 20, 3:37 PM EDT	Severe Thunderstorm Warning	PHI	53 min
May 20, 3:52 PM EDT	Areal Flood Advisory	PHI	3 hr
May 21, 12:12 AM EDT	Dense Fog Advisory	PHI	9 hr
May 22, 12:20 PM EDT	Mesoscale Discussion	SPC	2 hr
May 22, 1:53 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
May 22, 4:15 PM EDT	Mesoscale Discussion	SPC	90 min
May 22, 5:55 PM EDT	Severe Thunderstorm Warning	PHI	41 min
May 22, 6:32 PM EDT	Mesoscale Discussion	SPC	118 min
May 27, 3:23 AM EDT	Flood Watch	PHI	21 hr
May 27, 11:55 AM EDT	Mesoscale Discussion	SPC	95 min
May 27, 12:57 PM EDT	Severe Thunderstorm Watch	SPC	5 hr
May 27, 2:43 PM EDT	Special Weather Statement	PHI	47 min
May 27, 2:52 PM EDT	Special Weather Statement	PHI	23 min
May 27, 3:16 PM EDT	Mesoscale Discussion	SPC	89 min
May 27, 8:29 PM EDT	Mesoscale Discussion	SPC	91 min
May 27, 10:54 PM EDT	Special Weather Statement	PHI	66 min
May 28, 1:43 PM EDT	Special Weather Statement	PHI	62 min
Jun 1, 6:45 PM EDT	Severe Thunderstorm Warning	PHI	45 min
Jun 2, 1:04 PM EDT	Mesoscale Discussion	SPC	116 min
Jun 2, 1:53 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 2, 3:07 PM EDT	Flood Watch	PHI	5 hr
Jun 2, 5:58 PM EDT	Areal Flood Advisory	PHI	3 hr
Jun 9, 12:21 AM EDT	Areal Flood Advisory	PHI	6 hr
Jun 9, 1:39 AM EDT	Mesoscale Discussion	SPC	3 hr
Jun 9, 4:21 AM EDT	Flash Flood Warning	PHI	2 hr
Jun 9, 4:33 AM EDT	Severe Thunderstorm Warning	PHI	42 min
Jun 12, 7:10 AM EDT	Areal Flood Advisory	PHI	4 hr
Jun 12, 8:17 AM EDT	Areal Flood Advisory	PHI	3 hr
Jun 14, 7:14 AM EDT	Severe Thunderstorm Warning	PHI	46 min
Jun 14, 7:34 AM EDT	Special Weather Statement	PHI	26 min
Jul 1, 3:38 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 2, 1:16 PM EDT	Mesoscale Discussion	SPC	119 min
Jul 2, 3:02 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 2, 4:47 PM EDT	Mesoscale Discussion	SPC	118 min
Jul 7, 6:04 AM EDT	Areal Flood Advisory	PHI	3 hr
Jul 12, 4:02 PM EDT	Mesoscale Discussion	SPC	88 min
Jul 12, 5:05 PM EDT	Severe Thunderstorm Watch	SPC	4 hr
Jul 18, 12:18 PM EDT	Mesoscale Discussion	SPC	117 min
Jul 18, 1:47 PM EDT	Severe Thunderstorm Watch	SPC	6 hr
Jul 18, 4:32 PM EDT	Mesoscale Discussion	SPC	88 min
Jul 18, 6:38 PM EDT	Mesoscale Discussion	SPC	97 min
Jul 19, 4:03 AM EDT	Heat Advisory	PHI	3 days
Jul 19, 2:57 PM EDT	Excessive Heat Watch	PHI	13 hr
Jul 22, 3:14 PM EDT	Excessive Heat Warning	PHI	3 days
Jul 25, 1:02 PM EDT	Mesoscale Discussion	SPC	118 min
Jul 25, 1:46 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Jul 28, 3:32 PM EDT	Mesoscale Discussion	SPC	118 min
Jul 28, 4:02 PM EDT	Special Weather Statement	PHI	28 min
Jul 28, 7:29 PM EDT	Severe Thunderstorm Warning	PHI	46 min
Jul 28, 8:07 PM EDT	Severe Thunderstorm Warning	PHI	53 min
Jul 28, 8:44 PM EDT	Areal Flood Advisory	PHI	2 hr
Aug 2, 2:19 AM EDT	Special Weather Statement	PHI	26 min
Aug 2, 2:22 PM EDT	Heat Advisory	PHI	7 days
Aug 9, 10:04 AM EDT	Excessive Heat Warning	PHI	10 hr
Aug 9, 12:43 PM EDT	Mesoscale Discussion	SPC	2 hr
Aug 9, 6:03 PM EDT	Special Weather Statement	PHI	27 min
Aug 11, 3:17 AM EDT	Special Weather Statement	PHI	28 min
Aug 11, 3:46 AM EDT	Areal Flood Advisory	PHI	71 min
Aug 11, 3:57 AM EDT	Areal Flood Advisory	PHI	92 min
Aug 22, 12:18 AM EDT	Areal Flood Advisory	PHI	64 min
Aug 22, 4:10 PM EDT	Mesoscale Discussion	SPC	3 hr
Aug 30, 5:50 PM EDT	Mesoscale Discussion	SPC	115 min
Sep 5, 3:04 AM EDT	Flood Watch	PHI	35 hr
Sep 6, 5:11 AM EDT	Areal Flood Advisory	PHI	4 hr
Sep 6, 6:55 AM EDT	Flash Flood Warning	PHI	4 hr
Sep 6, 7:50 AM EDT	Areal Flood Advisory	PHI	4 hr
Sep 8, 3:03 AM EDT	Coastal Flood Advisory	PHI	25 hr
Sep 9, 4:21 AM EDT	Coastal Flood Advisory	PHI	24 hr
Sep 10, 4:18 AM EDT	Coastal Flood Advisory	PHI	23 hr
Sep 12, 5:46 PM EDT	Mesoscale Discussion	SPC	119 min
Sep 25, 2:17 PM EDT	Special Weather Statement	PHI	43 min
Sep 25, 2:35 PM EDT	Mesoscale Discussion	SPC	115 min
Sep 25, 2:43 PM EDT	Special Weather Statement	PHI	47 min
Sep 30, 3:55 PM EDT	Coastal Flood Advisory	PHI	4 days
Oct 2, 8:43 AM EDT	Areal Flood Advisory	PHI	3 hr
Oct 2, 3:18 PM EDT	Areal Flood Advisory	PHI	4 hr
Oct 4, 10:37 PM EDT	Areal Flood Advisory	PHI	64 min
Oct 17, 4:26 PM EDT	Special Weather Statement	PHI	49 min
Oct 17, 5:13 PM EDT	Special Weather Statement	PHI	32 min
Oct 18, 3:42 AM EDT	Frost Advisory	PHI	29 hr
Oct 19, 1:26 PM EDT	Frost Advisory	PHI	20 hr
Oct 20, 12:56 PM EDT	Frost Advisory	PHI	20 hr
Oct 25, 2:25 AM EDT	Dense Fog Advisory	PHI	7 hr
Oct 25, 9:40 PM EDT	Dense Fog Advisory	PHI	13 hr
Nov 4, 5:33 AM EDT	Dense Fog Advisory	PHI	6 hr
Nov 8, 5:49 PM EST	Frost Advisory	PHI	9 hr
Nov 12, 3:07 AM EST	Freeze Watch	PHI	24 hr
Nov 13, 3:24 AM EST	Freeze Warning	PHI	29 hr
Nov 14, 7:40 AM EST	Freeze Warning	PHI	25 hr
Nov 30, 3:48 PM EST	Special Weather Statement	PHI	42 min
Nov 30, 4:31 PM EST	Special Weather Statement	PHI	44 min
Dec 7, 8:26 AM EST	Dense Fog Advisory	PHI	3 hr
Dec 14, 3:16 AM EST	Winter Weather Advisory	PHI	45 hr
Dec 15, 8:49 PM EST	Areal Flood Advisory	PHI	3 hr
Dec 21, 3:20 PM EST	Coastal Flood Warning	PHI	50 hr
Dec 21, 3:27 PM EST	Flood Watch	PHI	34 hr
Dec 22, 3:38 AM EST	Wind Advisory	PHI	42 hr
Dec 22, 2:58 PM EST	Wind Chill Advisory	PHI	46 hr
Dec 23, 9:09 AM EST	Winter Weather Advisory	PHI	9 hr
Dec 31, 5:36 AM EST	Dense Fog Advisory	PHI	22 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	15
Severe Thunderstorm Watch	10
Tornado Watch	1
Mesoscale Discussion	34
Special Weather Statement	20
Flooding
Areal Flood Warning	1
Flash Flood Warning	2
River Flood Warning	2
Flood Watch	5
Areal Flood Advisory	20
Winter
Snow Squall Warning	1
Winter Storm Warning	1
Winter Storm Watch	1
Winter Weather Advisory	12
Heat
Excessive Heat Warning	2
Excessive Heat Watch	1
Heat Advisory	3
Cold
Freeze Warning	2
Freeze Watch	2
Frost Advisory	6
Wind Chill Advisory	1
Wind and dust
Wind Advisory	7
Fire
Red Flag Warning	2
Fire Weather Watch	2
Fog and smoke
Dense Fog Advisory	12
Coast and beach
Coastal Flood Warning	1
Coastal Flood Advisory	8

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2021 2023

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.