Alert archive / Delaware / New Castle County
Weather alerts in New Castle County, Delaware, 2026
197 weather alerts in 2026, 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 2026. Tap one for its archive.
- Alerts
- 197
- Warnings
- 83
- Watches
- 43
- Advisories
- 29
- Busiest month
- July58 alerts
- Busiest day
- July 28, 202611 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 New Castle County in 2026 had a tornado report inside them.
New Castle County, 2026
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 49 | 35 | 29% | 35 | 97% | 26 min |
| Flash flood warnings | 16 | 13 | 19% | 20 | 90% | 101 min |
Each office's whole area, 2026
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Philadelphia/Mount Holly: tornado warnings | 35 | 10 | 71% | 16 | 94% | 12 min |
| NWS Philadelphia/Mount Holly: severe thunderstorm warnings | 372 | 219 | 41% | 854 | 94% | 27 min |
| NWS Philadelphia/Mount Holly: flash flood warnings | 156 | 90 | 42% | 307 | 92% | 63 min |
An office's figures cover every county it serves, including across state lines.
The year is still running; reports filed late and damage surveys can still change these figures.
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 1, 4:44 AM EST | Snow Squall Warning | PHI | 46 min |
| Jan 1, 5:34 AM EST | Snow Squall Warning | PHI | 56 min |
| Jan 7, 12:12 AM EST | Dense Fog Advisory | PHI | 8 hr |
| Jan 17, 2:42 PM EST | Winter Weather Advisory | PHI | 29 hr |
| Jan 22, 2:12 AM EST | Winter Storm Watch | PHI | 34 hr |
| Jan 22, 12:59 PM EST | Cold Weather Advisory | PHI | 47 hr |
| Jan 23, 12:38 PM EST | Winter Storm Warning | PHI | 60 hr |
| Jan 25, 6:01 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Jan 25, 3:02 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 26, 1:16 AM EST | Cold Weather Advisory | PHI | 7 days |
| Feb 5, 12:15 PM EST | Extreme Cold Watch | PHI | 13 hr |
| Feb 5, 12:21 PM EST | High Wind Watch | PHI | 13 hr |
| Feb 6, 1:34 AM EST | Extreme Cold Warning | PHI | 3 days |
| Feb 6, 1:34 AM EST | High Wind Warning | PHI | 42 hr |
| Feb 6, 1:34 AM EST | Wind Advisory | PHI | 48 hr |
| Feb 7, 7:18 AM EST | Snow Squall Warning | PHI | 27 min |
| Feb 7, 7:45 AM EST | Snow Squall Warning | PHI | 30 min |
| Feb 8, 1:59 AM EST | Cold Weather Advisory | PHI | 32 hr |
| Feb 17, 1:15 PM EST | Dense Fog Advisory | PHI | 21 hr |
| Feb 20, 1:50 PM EST | Winter Storm Watch | PHI | 24 hr |
| Feb 21, 3:27 AM EST | Blizzard Warning | PHI | 58 hr |
| Feb 21, 3:27 AM EST | Winter Storm Warning | PHI | 58 hr |
| Feb 22, 4:47 AM EST | Coastal Flood Advisory | PHI | 23 hr |
| Feb 22, 4:58 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Mar 2, 11:44 AM EST | Winter Weather Advisory | PHI | 34 hr |
| Mar 3, 4:04 PM EST | Dense Fog Advisory | PHI | 6 hr |
| Mar 8, 1:22 AM EST | Dense Fog Advisory | PHI | 9 hr |
| Mar 9, 7:33 PM EDT | Dense Fog Advisory | PHI | 10 hr |
| Mar 11, 6:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Mar 11, 7:03 PM EDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Mar 11, 7:48 PM EDT | Severe Thunderstorm Warning | PHI | 42 min |
| Mar 11, 8:28 PM EDT | Severe Thunderstorm Warning | PHI | 47 min |
| Mar 15, 12:47 PM EDT | Wind Advisory | PHI | 37 hr |
| Mar 16, 11:30 AM EDT | Tornado Watch | SPC | 6 hr |
| Mar 16, 3:14 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Mar 16, 8:15 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Mar 16, 9:04 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Mar 16, 10:07 PM EDT | Severe Thunderstorm Warning | PHI | 53 min |
| Mar 16, 10:13 PM EDT | Severe Thunderstorm Warning | PHI | 62 min |
| Mar 16, 10:39 PM EDT | Severe Thunderstorm Warning | PHI | 51 min |
| Mar 21, 3:25 AM EDT | Dense Fog Advisory | PHI | 5 hr |
| Apr 1, 7:19 PM EDT | Severe Thunderstorm Warning | PHI | 41 min |
| Apr 3, 5:34 AM EDT | Dense Fog Advisory | PHI | 5 hr |
| Apr 6, 12:15 PM EDT | Freeze Watch | PHI | 14 hr |
| Apr 7, 2:19 AM EDT | Freeze Watch | PHI | 31 hr |
| Apr 7, 2:19 AM EDT | Freeze Warning | PHI | 31 hr |
| Apr 8, 8:55 AM EDT | Freeze Warning | PHI | 24 hr |
| Apr 17, 3:00 PM EDT | Coastal Flood Advisory | PHI | 39 hr |
| Apr 18, 1:02 PM EDT | Freeze Watch | PHI | 37 hr |
| Apr 20, 2:25 AM EDT | Freeze Warning | PHI | 31 hr |
| Apr 29, 5:41 PM EDT | Coastal Flood Advisory | PHI | 11 hr |
| May 10, 3:10 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| May 18, 2:52 AM EDT | Heat Advisory | PHI | 64 hr |
| May 19, 5:40 PM EDT | Mesoscale Discussion | SPC | 65 min |
| May 20, 1:52 PM EDT | Mesoscale Discussion | SPC | 53 min |
| May 20, 2:10 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 20, 4:50 PM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| May 20, 5:18 PM EDT | Severe Thunderstorm Warning | PHI | 42 min |
| May 20, 5:29 PM EDT | Severe Thunderstorm Warning | PHI | 46 min |
| May 20, 5:29 PM EDT | Mesoscale Discussion | SPC | 61 min |
| May 20, 5:35 PM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| May 27, 11:20 AM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| Jun 6, 4:17 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jun 6, 4:45 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 6, 6:17 PM EDT | Severe Thunderstorm Warning | PHI | 58 min |
| Jun 6, 6:36 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Jun 10, 2:24 AM EDT | Heat Advisory | PHI | 66 hr |
| Jun 11, 3:02 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jun 11, 6:09 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 11, 7:14 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 14, 6:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jun 14, 7:06 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 14, 9:25 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 14, 9:54 PM EDT | Severe Thunderstorm Warning | PHI | 51 min |
| Jun 14, 10:15 PM EDT | Flash Flood Warning | PHI | 3 hr |
| Jun 14, 10:38 PM EDT | Flash Flood Warning | PHI | 3 hr |
| Jun 17, 4:51 PM EDT | Coastal Flood Advisory | PHI | 11 hr |
| Jun 22, 2:13 AM EDT | Flood Watch | PHI | 25 hr |
| Jun 22, 1:25 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 22, 2:08 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 22, 4:45 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 28, 3:57 AM EDT | Extreme Heat Watch | PHI | 71 hr |
| Jun 30, 2:44 AM EDT | Extreme Heat Warning | PHI | 5 days |
| Jul 3, 3:25 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 4, 3:28 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 4, 6:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jul 4, 8:17 PM EDT | Severe Thunderstorm Warning | PHI | 43 min |
| Jul 4, 8:19 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jul 4, 8:38 PM EDT | Severe Thunderstorm Warning | PHI | 52 min |
| Jul 4, 8:48 PM EDT | Severe Thunderstorm Warning | PHI | 57 min |
| Jul 4, 8:59 PM EDT | Severe Thunderstorm Warning | PHI | 46 min |
| Jul 4, 10:52 PM EDT | Heat Advisory | PHI | 21 hr |
| Jul 5, 2:33 AM EDT | Flood Watch | PHI | 41 hr |
| Jul 5, 6:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 5, 6:44 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 5, 7:04 PM EDT | Severe Thunderstorm Warning | PHI | 41 min |
| Jul 5, 8:20 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 5, 10:05 PM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| Jul 5, 10:37 PM EDT | Severe Thunderstorm Warning | PHI | 38 min |
| Jul 5, 11:00 PM EDT | Flash Flood Warning | PHI | 4 hr |
| Jul 5, 11:30 PM EDT | Severe Thunderstorm Warning | PHI | 45 min |
| Jul 9, 2:09 AM EDT | Flood Watch | PHI | 19 hr |
| Jul 9, 1:37 PM EDT | Flash Flood Warning | PHI | 6 hr |
| Jul 9, 2:05 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 9, 2:30 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 9, 4:30 PM EDT | Flash Flood Warning | PHI | 4 hr |
| Jul 9, 5:30 PM EDT | Severe Thunderstorm Warning | PHI | 45 min |
| Jul 11, 2:56 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 12, 4:25 AM EDT | Coastal Flood Advisory | PHI | 20 hr |
| Jul 13, 2:08 AM EDT | Extreme Heat Watch | PHI | 25 hr |
| Jul 14, 2:38 AM EDT | Extreme Heat Warning | PHI | 41 hr |
| Jul 16, 12:10 AM EDT | Heat Advisory | PHI | 20 hr |
| Jul 17, 1:40 PM EDT | Flood Watch | PHI | 33 hr |
| Jul 18, 12:50 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Jul 18, 1:55 PM EDT | Tornado Watch | SPC | 6 hr |
| Jul 18, 4:39 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jul 18, 5:14 PM EDT | Severe Thunderstorm Warning | PHI | 61 min |
| Jul 20, 2:44 PM EDT | Flood Watch | PHI | 31 hr |
| Jul 21, 1:23 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 2:06 PM EDT | Tornado Watch | SPC | 7 hr |
| Jul 21, 3:40 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jul 21, 3:58 PM EDT | Severe Thunderstorm Warning | PHI | 47 min |
| Jul 21, 4:38 PM EDT | Flash Flood Warning | PHI | 4 hr |
| Jul 21, 4:43 PM EDT | Severe Thunderstorm Warning | PHI | 47 min |
| Jul 21, 5:30 PM EDT | Severe Thunderstorm Warning | PHI | 45 min |
| Jul 21, 6:00 PM EDT | Severe Thunderstorm Warning | PHI | 45 min |
| Jul 21, 6:53 PM EDT | Flash Flood Warning | PHI | 3 hr |
| Jul 27, 2:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 27, 2:15 PM EDT | Flood Watch | PHI | 38 hr |
| Jul 27, 7:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Jul 28, 12:08 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 28, 12:51 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 28, 4:20 PM EDT | Tornado Watch | SPC | 5 hr |
| Jul 28, 4:53 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 28, 5:29 PM EDT | Severe Thunderstorm Warning | PHI | 61 min |
| Jul 28, 6:08 PM EDT | Severe Thunderstorm Warning | PHI | 52 min |
| Jul 28, 6:16 PM EDT | Tornado Warning | PHI | 29 min |
| Jul 28, 6:23 PM EDT | Severe Thunderstorm Warning | PHI | 67 min |
| Jul 28, 6:38 PM EDT | Severe Thunderstorm Warning | PHI | 67 min |
| Jul 28, 6:46 PM EDT | Tornado Warning | PHI | 29 min |
| Jul 28, 7:11 PM EDT | Flash Flood Warning | PHI | 3 hr |
| Aug 2, 2:20 PM EDT | Flood Watch | PHI | 26 hr |
| Aug 3, 9:08 AM EDT | Flash Flood Warning | PHI | 3 hr |
| Aug 5, 1:50 PM EDT | Heat Advisory | PHI | 3 days |
| Aug 7, 12:50 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 7, 1:22 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 7, 4:56 PM EDT | Severe Thunderstorm Warning | PHI | 64 min |
| Aug 8, 11:55 AM EDT | Mesoscale Discussion | SPC | 95 min |
| Aug 8, 1:12 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 8, 1:26 PM EDT | Severe Thunderstorm Warning | PHI | 49 min |
| Aug 8, 1:44 PM EDT | Severe Thunderstorm Warning | PHI | 46 min |
| Aug 10, 9:29 AM EDT | Mesoscale Discussion | SPC | 91 min |
| Aug 10, 2:10 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 10, 4:19 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Aug 10, 4:39 PM EDT | Severe Thunderstorm Warning | PHI | 66 min |
| Aug 10, 4:46 PM EDT | Severe Thunderstorm Warning | PHI | 20 min |
| Aug 10, 5:36 PM EDT | Severe Thunderstorm Warning | PHI | 39 min |
| Aug 10, 6:07 PM EDT | Severe Thunderstorm Warning | PHI | 38 min |
| Aug 11, 3:23 AM EDT | Coastal Flood Advisory | PHI | 23 hr |
| Aug 11, 4:56 PM EDT | Coastal Flood Advisory | PHI | 33 hr |
| Aug 17, 4:43 AM EDT | Flash Flood Warning | PHI | 2 hr |
| Aug 17, 6:45 PM EDT | Severe Thunderstorm Warning | PHI | 32 min |
| Aug 19, 2:08 PM EDT | Flood Watch | PHI | 31 hr |
| Aug 20, 1:53 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 20, 2:31 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 20, 2:58 PM EDT | Tornado Watch | SPC | 7 hr |
| Aug 20, 4:26 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 20, 4:50 PM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| Aug 20, 5:27 PM EDT | Severe Thunderstorm Warning | PHI | 48 min |
| Aug 20, 5:39 PM EDT | Flash Flood Warning | PHI | 4 hr |
| Aug 20, 6:09 PM EDT | Severe Thunderstorm Warning | PHI | 51 min |
| Aug 20, 6:13 PM EDT | Severe Thunderstorm Warning | PHI | 47 min |
| Aug 23, 3:32 AM EDT | Flash Flood Warning | PHI | 3 hr |
| Aug 26, 2:31 PM EDT | Flood Watch | PHI | 35 hr |
| Aug 27, 10:57 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 27, 11:38 AM EDT | Flash Flood Warning | PHI | 4 hr |
| Aug 27, 12:51 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 27, 1:32 PM EDT | Severe Thunderstorm Warning | PHI | 43 min |
| Aug 27, 1:50 PM EDT | Flash Flood Warning | PHI | 4 hr |
| Aug 27, 3:26 PM EDT | Areal Flood Warning | PHI | 5 hr |
| Sep 1, 2:30 AM EDT | Heat Advisory | PHI | 18 hr |
| Sep 1, 3:13 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 1, 4:32 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 1, 6:32 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Sep 1, 7:43 PM EDT | Severe Thunderstorm Warning | PHI | 47 min |
| Sep 1, 8:17 PM EDT | Severe Thunderstorm Warning | PHI | 58 min |
| Sep 1, 8:44 PM EDT | Flash Flood Warning | PHI | 3 hr |
| Sep 1, 8:46 PM EDT | Severe Thunderstorm Warning | PHI | 59 min |
| Sep 1, 9:40 PM EDT | Severe Thunderstorm Warning | PHI | 65 min |
| Sep 1, 9:46 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Sep 2, 3:53 AM EDT | Heat Advisory | PHI | 40 hr |
| Sep 2, 1:35 PM EDT | Severe Thunderstorm Warning | PHI | 40 min |
| Sep 3, 1:34 AM EDT | Flash Flood Warning | PHI | 4 hr |
| Sep 3, 5:26 AM EDT | Areal Flood Warning | PHI | 4 hr |
| Sep 3, 8:38 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Sep 12, 2:21 AM EDT | Flood Watch | PHI | 34 hr |
| Sep 21, 1:24 PM EDT | Coastal Flood Advisory | PHI | 4 days |
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 | 49 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 19 |
| Tornado Watch | 5 |
| Mesoscale Discussion | 42 |
| Flooding | |
| Areal Flood Warning | 2 |
| Flash Flood Warning | 16 |
| Flood Watch | 10 |
| Winter | |
| Blizzard Warning | 1 |
| Snow Squall Warning | 4 |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 2 |
| Winter Weather Advisory | 2 |
| Heat | |
| Extreme Heat Warning | 2 |
| Extreme Heat Watch | 2 |
| Heat Advisory | 7 |
| Cold | |
| Extreme Cold Warning | 1 |
| Freeze Warning | 3 |
| Extreme Cold Watch | 1 |
| Freeze Watch | 3 |
| Cold Weather Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 2 |
| Fog and smoke | |
| Dense Fog Advisory | 7 |
| Coast and beach | |
| Coastal Flood Advisory | 8 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive2025
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.