Alert archive / Delaware / New Castle County

Weather alerts in New Castle County, Delaware, 2024

186 weather alerts in 2024, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

New Castle County and its neighbors

Each county as a circle sized by its count in 2024. Tap one for its archive.

Alerts: 186
Warnings: 69
Watches: 25
Advisories: 64
Busiest month: August40 alerts
Busiest day: June 6, 202410 alerts

Over time

By month

Warning verification

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

1 of 4 tornado warnings covering New Castle County in 2024 had a tornado report inside them; 1 of 1 tornado reports fell inside a warning, on average 13 minutes after it went out.

New Castle County, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
Tornado warnings	4	1	75%	1	100%	13 min
Severe thunderstorm warnings	23	13	43%	16	69%	29 min
Flash flood warnings	6	3	50%	7	100%	175 min

Each office's whole area, 2024

	Warnings	With a report	False alarm ratio	Reports	Inside a warning	Mean lead time
NWS Philadelphia/Mount Holly: tornado warnings	7	1	86%	1	100%	13 min
NWS Philadelphia/Mount Holly: severe thunderstorm warnings	219	137	37%	463	90%	23 min
NWS Philadelphia/Mount Holly: flash flood warnings	66	27	59%	61	84%	86 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
Jan 7, 3:15 PM EST	Flood Watch	PHI	60 hr
Jan 7, 3:20 PM EST	Coastal Flood Watch	PHI	25 hr
Jan 8, 3:27 PM EST	Wind Advisory	PHI	33 hr
Jan 8, 4:33 PM EST	Coastal Flood Warning	PHI	53 hr
Jan 9, 5:03 AM EST	Coastal Flood Advisory	PHI	38 hr
Jan 9, 6:08 PM EST	Areal Flood Warning	PHI	9 hr
Jan 9, 6:36 PM EST	River Flood Warning	PHI	10 hr
Jan 9, 7:10 PM EST	River Flood Warning	PHI	10 hr
Jan 9, 7:16 PM EST	River Flood Warning	PHI	14 hr
Jan 9, 8:15 PM EST	Areal Flood Warning	PHI	5 hr
Jan 10, 3:47 AM EST	Wind Advisory	PHI	12 hr
Jan 10, 5:51 AM EST	River Flood Warning	PHI	13 hr
Jan 11, 1:06 PM EST	Flood Watch	PHI	39 hr
Jan 11, 3:46 PM EST	Coastal Flood Warning	PHI	56 hr
Jan 11, 3:46 PM EST	Coastal Flood Advisory	PHI	3 days
Jan 11, 3:48 PM EST	Wind Advisory	PHI	49 hr
Jan 14, 2:48 AM EST	Wind Advisory	PHI	15 hr
Jan 14, 12:17 PM EST	Snow Squall Warning	PHI	28 min
Jan 15, 4:12 AM EST	Winter Weather Advisory	PHI	35 hr
Jan 16, 8:49 AM EST	Mesoscale Discussion	SPC	4 hr
Jan 17, 3:16 PM EST	Winter Weather Advisory	PHI	53 hr
Jan 18, 2:48 PM EST	Winter Storm Warning	PHI	29 hr
Jan 24, 10:59 AM EST	Dense Fog Advisory	PHI	3 hr
Jan 25, 6:41 PM EST	Dense Fog Advisory	PHI	17 hr
Jan 26, 5:33 PM EST	Dense Fog Advisory	PHI	16 hr
Jan 27, 4:04 PM EST	Coastal Flood Advisory	PHI	4 days
Feb 5, 9:20 AM EST	Coastal Flood Advisory	PHI	5 days
Feb 10, 7:29 PM EST	Coastal Flood Advisory	PHI	23 hr
Feb 11, 4:02 PM EST	Coastal Flood Advisory	PHI	63 hr
Feb 12, 4:15 AM EST	Winter Weather Advisory	PHI	33 hr
Feb 15, 3:33 PM EST	Winter Weather Advisory	PHI	42 hr
Feb 16, 3:28 PM EST	Winter Storm Warning	PHI	18 hr
Feb 27, 3:16 PM EST	Wind Advisory	PHI	35 hr
Mar 7, 11:34 AM EST	Coastal Flood Advisory	PHI	26 hr
Mar 8, 2:36 PM EST	Coastal Flood Watch	PHI	13 hr
Mar 8, 2:36 PM EST	Coastal Flood Advisory	PHI	60 hr
Mar 9, 3:51 AM EST	Coastal Flood Warning	PHI	37 hr
Mar 9, 2:43 PM EST	Wind Advisory	PHI	51 hr
Mar 9, 8:00 PM EST	Areal Flood Advisory	PHI	3 hr
Mar 9, 10:14 PM EST	River Flood Warning	PHI	4 hr
Mar 9, 10:32 PM EST	River Flood Warning	PHI	4 hr
Mar 13, 3:46 AM EDT	Coastal Flood Advisory	PHI	28 hr
Mar 21, 3:29 PM EDT	Flood Watch	PHI	51 hr
Mar 22, 2:17 PM EDT	Wind Advisory	PHI	36 hr
Mar 23, 8:50 AM EDT	Areal Flood Advisory	PHI	2 hr
Mar 23, 11:15 AM EDT	Areal Flood Warning	PHI	6 hr
Mar 23, 11:35 AM EDT	Areal Flood Advisory	PHI	3 hr
Mar 23, 12:26 PM EDT	River Flood Warning	PHI	6 hr
Mar 23, 3:05 PM EDT	River Flood Warning	PHI	117 min
Mar 25, 4:48 AM EDT	Coastal Flood Advisory	PHI	59 hr
Apr 1, 3:33 PM EDT	Coastal Flood Advisory	PHI	4 days
Apr 2, 1:59 PM EDT	Flood Watch	PHI	37 hr
Apr 3, 3:29 PM EDT	River Flood Warning	PHI	8 hr
Apr 3, 3:35 PM EDT	River Flood Warning	PHI	7 hr
Apr 3, 4:23 PM EDT	Areal Flood Warning	PHI	5 hr
Apr 6, 3:39 PM EDT	Coastal Flood Advisory	PHI	4 days
Apr 10, 10:56 AM EDT	Coastal Flood Watch	PHI	28 hr
Apr 10, 10:56 AM EDT	Coastal Flood Advisory	PHI	20 hr
Apr 11, 5:00 AM EDT	Coastal Flood Warning	PHI	28 hr
Apr 14, 9:04 PM EDT	Special Weather Statement	PHI	41 min
Apr 14, 9:43 PM EDT	Special Weather Statement	PHI	47 min
Apr 15, 3:53 PM EDT	Severe Thunderstorm Warning	PHI	43 min
Apr 21, 3:16 PM EDT	Frost Advisory	PHI	18 hr
Apr 22, 9:51 AM EDT	Frost Advisory	PHI	23 hr
Apr 25, 12:37 PM EDT	Frost Advisory	PHI	20 hr
May 6, 12:06 AM EDT	Dense Fog Advisory	PHI	10 hr
May 7, 4:07 AM EDT	Coastal Flood Advisory	PHI	25 hr
May 8, 5:06 AM EDT	Coastal Flood Advisory	PHI	24 hr
May 9, 5:27 AM EDT	Coastal Flood Advisory	PHI	25 hr
May 10, 5:12 AM EDT	Coastal Flood Advisory	PHI	29 hr
May 11, 1:28 PM EDT	Coastal Flood Advisory	PHI	20 hr
May 27, 11:53 AM EDT	Mesoscale Discussion	SPC	2 hr
May 27, 1:42 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
May 27, 7:40 PM EDT	Mesoscale Discussion	SPC	2 hr
Jun 4, 4:33 AM EDT	Coastal Flood Advisory	PHI	23 hr
Jun 5, 9:45 AM EDT	Coastal Flood Advisory	PHI	19 hr
Jun 5, 8:36 PM EDT	Tornado Warning	PHI	24 min
Jun 5, 10:17 PM EDT	Mesoscale Discussion	SPC	58 min
Jun 5, 10:57 PM EDT	Tornado Warning	PHI	33 min
Jun 5, 11:27 PM EDT	Tornado Warning	PHI	33 min
Jun 6, 12:18 AM EDT	Flash Flood Warning	PHI	3 hr
Jun 6, 12:42 AM EDT	River Flood Warning	PHI	3 hr
Jun 6, 4:27 AM EDT	River Flood Warning	PHI	3 hr
Jun 6, 1:45 PM EDT	Mesoscale Discussion	SPC	90 min
Jun 6, 2:26 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jun 6, 4:18 PM EDT	Mesoscale Discussion	SPC	87 min
Jun 16, 3:47 AM EDT	Heat Advisory	PHI	8 days
Jun 16, 3:14 PM EDT	Excessive Heat Watch	PHI	6 days
Jun 22, 3:47 AM EDT	Excessive Heat Warning	PHI	40 hr
Jun 23, 4:48 PM EDT	Severe Thunderstorm Warning	PHI	42 min
Jun 23, 5:22 PM EDT	Severe Thunderstorm Warning	PHI	53 min
Jun 23, 6:03 PM EDT	Severe Thunderstorm Warning	PHI	42 min
Jun 23, 7:24 PM EDT	Severe Thunderstorm Warning	PHI	51 min
Jun 23, 8:42 PM EDT	Severe Thunderstorm Warning	PHI	48 min
Jun 25, 2:50 AM EDT	Heat Advisory	PHI	42 hr
Jun 26, 4:02 PM EDT	Mesoscale Discussion	SPC	118 min
Jun 28, 2:33 PM EDT	Heat Advisory	PHI	52 hr
Jun 30, 9:55 AM EDT	Mesoscale Discussion	SPC	2 hr
Jun 30, 11:09 AM EDT	Severe Thunderstorm Watch	SPC	10 hr
Jun 30, 5:20 PM EDT	Severe Thunderstorm Warning	PHI	40 min
Jun 30, 5:51 PM EDT	Severe Thunderstorm Warning	PHI	39 min
Jun 30, 6:03 PM EDT	Mesoscale Discussion	SPC	87 min
Jun 30, 6:08 PM EDT	Severe Thunderstorm Warning	PHI	52 min
Jun 30, 7:00 PM EDT	Severe Thunderstorm Warning	PHI	45 min
Jun 30, 7:31 PM EDT	Severe Thunderstorm Warning	PHI	44 min
Jun 30, 8:15 PM EDT	Severe Thunderstorm Warning	PHI	45 min
Jun 30, 8:45 PM EDT	Flash Flood Warning	PHI	4 hr
Jun 30, 9:03 PM EDT	River Flood Warning	PHI	3 hr
Jul 4, 3:34 AM EDT	Heat Advisory	PHI	64 hr
Jul 6, 3:05 AM EDT	Excessive Heat Warning	PHI	17 hr
Jul 7, 2:42 PM EDT	Heat Advisory	PHI	3 days
Jul 9, 3:01 PM EDT	Excessive Heat Warning	PHI	29 hr
Jul 11, 2:43 PM EDT	Flood Watch	PHI	43 hr
Jul 12, 3:37 PM EDT	Excessive Heat Watch	PHI	72 hr
Jul 12, 3:37 PM EDT	Heat Advisory	PHI	5 days
Jul 14, 12:56 PM EDT	Mesoscale Discussion	SPC	3 hr
Jul 14, 3:03 PM EDT	Excessive Heat Warning	PHI	3 days
Jul 14, 3:35 PM EDT	Severe Thunderstorm Warning	PHI	40 min
Jul 16, 2:35 PM EDT	Mesoscale Discussion	SPC	115 min
Jul 16, 3:36 PM EDT	Severe Thunderstorm Watch	SPC	9 hr
Jul 16, 6:20 PM EDT	Mesoscale Discussion	SPC	115 min
Jul 16, 8:19 PM EDT	Mesoscale Discussion	SPC	116 min
Jul 16, 8:23 PM EDT	Severe Thunderstorm Warning	PHI	67 min
Jul 16, 9:04 PM EDT	Severe Thunderstorm Warning	PHI	56 min
Jul 16, 10:17 PM EDT	Severe Thunderstorm Warning	PHI	58 min
Jul 16, 11:08 PM EDT	Severe Thunderstorm Warning	PHI	67 min
Jul 17, 2:11 PM EDT	Mesoscale Discussion	SPC	79 min
Jul 17, 2:38 PM EDT	Severe Thunderstorm Watch	SPC	7 hr
Jul 17, 7:56 PM EDT	Severe Thunderstorm Warning	PHI	44 min
Jul 17, 7:57 PM EDT	Mesoscale Discussion	SPC	2 hr
Jul 31, 3:56 AM EDT	Heat Advisory	PHI	64 hr
Jul 31, 4:11 PM EDT	Severe Thunderstorm Warning	PHI	34 min
Aug 1, 2:53 PM EDT	Mesoscale Discussion	SPC	2 hr
Aug 2, 4:17 AM EDT	Excessive Heat Warning	PHI	16 hr
Aug 2, 3:45 PM EDT	Mesoscale Discussion	SPC	60 min
Aug 2, 4:07 PM EDT	Severe Thunderstorm Watch	SPC	4 hr
Aug 2, 4:32 PM EDT	Severe Thunderstorm Warning	PHI	24 min
Aug 2, 5:05 PM EDT	Severe Thunderstorm Warning	PHI	40 min
Aug 2, 7:01 PM EDT	Mesoscale Discussion	SPC	59 min
Aug 2, 9:12 PM EDT	Severe Thunderstorm Warning	PHI	48 min
Aug 2, 9:40 PM EDT	Flash Flood Warning	PHI	4 hr
Aug 3, 3:17 AM EDT	Heat Advisory	PHI	17 hr
Aug 3, 12:20 PM EDT	Flood Watch	PHI	9 hr
Aug 3, 12:56 PM EDT	Mesoscale Discussion	SPC	94 min
Aug 3, 1:20 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Aug 3, 5:38 PM EDT	Severe Thunderstorm Warning Considerable damage threat	PHI	97 min
Aug 5, 3:16 AM EDT	Flood Watch	PHI	48 hr
Aug 6, 9:37 AM EDT	Heat Advisory	PHI	9 hr
Aug 6, 1:06 PM EDT	Mesoscale Discussion	SPC	84 min
Aug 6, 6:31 PM EDT	Mesoscale Discussion	SPC	89 min
Aug 8, 2:20 PM EDT	Coastal Flood Advisory	PHI	40 hr
Aug 8, 3:13 PM EDT	Wind Advisory	PHI	27 hr
Aug 8, 3:46 PM EDT	Flash Flood Warning	PHI	7 hr
Aug 8, 5:26 PM EDT	River Flood Warning	PHI	14 hr
Aug 8, 5:26 PM EDT	River Flood Warning	PHI	6 hr
Aug 8, 5:48 PM EDT	Flash Flood Warning	PHI	6 hr
Aug 8, 6:04 PM EDT	Flood Watch	PHI	24 hr
Aug 8, 6:59 PM EDT	Tornado Warning	PHI	31 min
Aug 8, 9:56 PM EDT	River Flood Warning	PHI	7 hr
Aug 8, 10:20 PM EDT	Areal Flood Warning	PHI	11 hr
Aug 8, 11:40 PM EDT	Areal Flood Warning	PHI	4 hr
Aug 9, 6:17 AM EDT	Tornado Watch	SPC	8 hr
Aug 9, 10:26 AM EDT	Mesoscale Discussion	SPC	94 min
Aug 17, 5:01 AM EDT	Coastal Flood Advisory	PHI	70 hr
Aug 17, 3:26 PM EDT	Flood Watch	PHI	33 hr
Aug 18, 1:09 PM EDT	Mesoscale Discussion	SPC	96 min
Aug 18, 2:02 PM EDT	Severe Thunderstorm Watch	SPC	8 hr
Aug 18, 4:30 PM EDT	Mesoscale Discussion	SPC	90 min
Aug 19, 2:25 PM EDT	Mesoscale Discussion	SPC	2 hr
Aug 26, 3:20 PM EDT	Excessive Heat Watch	PHI	13 hr
Aug 27, 3:59 AM EDT	Heat Advisory	PHI	40 hr
Aug 29, 11:14 PM EDT	Flash Flood Warning	PHI	3 hr
Sep 12, 4:15 AM EDT	Dense Fog Advisory	PHI	6 hr
Sep 18, 4:45 AM EDT	Coastal Flood Advisory	PHI	6 days
Sep 27, 5:07 AM EDT	Dense Fog Advisory	PHI	4 hr
Oct 26, 3:06 AM EDT	Freeze Watch	PHI	24 hr
Oct 27, 2:58 AM EDT	Freeze Warning	PHI	30 hr
Nov 7, 2:54 PM EST	Red Flag Warning	PHI	27 hr
Nov 13, 5:18 PM EST	Coastal Flood Advisory	PHI	6 days
Nov 20, 3:19 PM EST	Wind Advisory	PHI	12 hr
Dec 3, 3:03 PM EST	Wind Advisory	PHI	55 hr
Dec 9, 9:43 PM EST	Dense Fog Advisory	PHI	13 hr
Dec 10, 2:42 PM EST	Wind Advisory	PHI	30 hr
Dec 23, 2:24 AM EST	Winter Weather Advisory	PHI	33 hr
Dec 28, 6:16 PM EST	Dense Fog Advisory	PHI	16 hr
Dec 31, 6:56 PM EST	Mesoscale Discussion	SPC	2 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	23
Tornado Warning	4
Severe Thunderstorm Watch	8
Tornado Watch	1
Mesoscale Discussion	26
Special Weather Statement	2
Flooding
Areal Flood Warning	6
Flash Flood Warning	6
River Flood Warning	16
Flood Watch	9
Areal Flood Advisory	3
Winter
Snow Squall Warning	1
Winter Storm Warning	2
Winter Weather Advisory	5
Heat
Excessive Heat Warning	5
Excessive Heat Watch	3
Heat Advisory	10
Cold
Freeze Warning	1
Freeze Watch	1
Frost Advisory	3
Wind and dust
Wind Advisory	11
Fire
Red Flag Warning	1
Fog and smoke
Dense Fog Advisory	8
Coast and beach
Coastal Flood Warning	4
Coastal Flood Watch	3
Coastal Flood Advisory	24

The busiest days

Days with the most alerts issued, by UTC date.

Nearby

Alerts in force now Tornadoes on record Forecast The radar archive 2023 2025

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.