Alert archive / Pennsylvania / Northumberland County
Weather alerts in Northumberland County, Pennsylvania, 2021
154 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Northumberland County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 154
- Warnings
- 42
- Watches
- 28
- Advisories
- 35
- Busiest month
- July48 alerts
- Busiest day
- July 17, 20219 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 1 tornado warnings covering Northumberland County in 2021 had a tornado report inside them.
Northumberland County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 28 | 25 | 11% | 14 | 93% | 28 min |
| Flash flood warnings | 3 | 3 | 0% | 1 | 100% | 60 min |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS State College, PA: tornado warnings | 11 | 3 | 73% | 12 | 25% | 7 min |
| NWS State College, PA: severe thunderstorm warnings | 289 | 212 | 27% | 458 | 87% | 23 min |
| NWS State College, PA: flash flood warnings | 31 | 20 | 35% | 46 | 89% | 118 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 2, 3:16 PM EST | Winter Weather Advisory | CTP | 32 hr |
| Jan 25, 3:29 AM EST | Winter Weather Advisory | CTP | 43 hr |
| Jan 26, 8:46 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 30, 3:24 PM EST | Winter Storm Warning | CTP | 13 hr |
| Jan 31, 4:52 AM EST | Winter Storm Warning | CTP | 48 hr |
| Feb 8, 1:58 PM EST | Winter Weather Advisory | CTP | 22 hr |
| Feb 10, 4:33 AM EST | Winter Weather Advisory | CTP | 28 hr |
| Feb 13, 2:53 PM EST | Winter Weather Advisory | CTP | 17 hr |
| Feb 14, 3:46 PM EST | Winter Weather Advisory | CTP | 38 hr |
| Feb 15, 3:28 PM EST | Ice Storm Warning | CTP | 15 hr |
| Feb 15, 9:16 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 16, 3:35 PM EST | Winter Storm Watch | CTP | 23 hr |
| Feb 17, 2:39 PM EST | Winter Weather Advisory | CTP | 22 hr |
| Feb 18, 12:25 PM EST | Winter Weather Advisory | CTP | 22 hr |
| Feb 21, 2:29 PM EST | Winter Weather Advisory | CTP | 23 hr |
| Feb 22, 7:48 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Feb 22, 8:15 AM EST | Snow Squall Warning | CTP | 90 min |
| Mar 1, 2:33 AM EST | Dense Fog Advisory | CTP | 5 hr |
| Mar 1, 3:40 AM EST | Wind Advisory | CTP | 23 hr |
| Mar 13, 2:42 PM EST | Fire Weather Watch | CTP | 13 hr |
| Mar 14, 4:19 AM EDT | Red Flag Warning | CTP | 18 hr |
| Mar 25, 11:51 AM EDT | Wind Advisory | CTP | 30 hr |
| Mar 28, 3:52 PM EDT | Special Weather Statement | CTP | 38 min |
| Apr 21, 2:11 AM EDT | Freeze Watch | CTP | 5 hr |
| Apr 21, 7:07 AM EDT | Freeze Warning | CTP | 26 hr |
| Apr 22, 9:16 AM EDT | Freeze Watch | CTP | 4 hr |
| Apr 22, 1:06 PM EDT | Freeze Warning | CTP | 20 hr |
| Apr 29, 8:21 PM EDT | Wind Advisory | CTP | 30 hr |
| May 8, 4:05 AM EDT | Frost Advisory | CTP | 28 hr |
| May 23, 1:20 PM EDT | Mesoscale Discussion | SPC | 115 min |
| May 26, 12:16 PM EDT | Mesoscale Discussion | SPC | 119 min |
| May 26, 12:59 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 26, 2:33 PM EDT | Severe Thunderstorm Warning | CTP | 57 min |
| May 26, 8:29 PM EDT | Severe Thunderstorm Warning | CTP | 32 min |
| Jun 13, 2:38 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 13, 3:26 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 13, 4:56 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jun 13, 7:21 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jun 14, 1:40 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 14, 2:06 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 14, 3:18 PM EDT | Severe Thunderstorm Warning | CTP | 57 min |
| Jun 20, 9:23 PM EDT | Severe Thunderstorm Warning | CTP | 50 min |
| Jun 21, 1:51 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Jun 21, 2:20 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 21, 5:52 PM EDT | Special Weather Statement | CTP | 23 min |
| Jun 28, 10:35 PM EDT | Heat Advisory | CTP | 20 hr |
| Jun 29, 8:56 PM EDT | Heat Advisory | CTP | 22 hr |
| Jun 30, 12:46 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 3:29 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 3:46 PM EDT | Severe Thunderstorm Warning | CTP | 44 min |
| Jun 30, 4:41 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 2, 3:08 PM EDT | Special Weather Statement | CTP | 37 min |
| Jul 2, 3:13 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Jul 6, 12:33 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 6, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 7, 2:41 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 7, 4:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jul 7, 7:11 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 7, 7:31 PM EDT | Severe Thunderstorm Warning | CTP | 44 min |
| Jul 7, 8:10 PM EDT | Special Weather Statement | CTP | 35 min |
| Jul 7, 8:12 PM EDT | Severe Thunderstorm Warning | CTP | 48 min |
| Jul 9, 4:35 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 11, 2:40 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 11, 5:41 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jul 11, 8:03 PM EDT | Severe Thunderstorm Warning | CTP | 42 min |
| Jul 11, 8:43 PM EDT | Severe Thunderstorm Warning | CTP | 62 min |
| Jul 11, 8:58 PM EDT | Mesoscale Discussion | SPC | 62 min |
| Jul 11, 9:07 PM EDT | Areal Flood Advisory | CTP | 2 hr |
| Jul 12, 1:21 PM EDT | Flash Flood Watch | CTP | 13 hr |
| Jul 12, 1:32 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jul 13, 12:39 PM EDT | Flash Flood Watch | CTP | 11 hr |
| Jul 13, 12:48 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jul 13, 1:37 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 13, 4:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jul 13, 6:44 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Jul 13, 8:17 PM EDT | Severe Thunderstorm Warning | CTP | 43 min |
| Jul 13, 8:51 PM EDT | Tornado Warning | CTP | 24 min |
| Jul 13, 9:12 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Jul 13, 9:30 PM EDT | Severe Thunderstorm Warning | CTP | 60 min |
| Jul 13, 10:18 PM EDT | Areal Flood Advisory | CTP | 117 min |
| Jul 13, 10:18 PM EDT | Severe Thunderstorm Warning | CTP | 57 min |
| Jul 14, 12:12 AM EDT | Areal Flood Advisory | CTP | 2 hr |
| Jul 16, 1:46 PM EDT | Flash Flood Watch | CTP | 32 hr |
| Jul 16, 2:59 PM EDT | Areal Flood Advisory | CTP | 2 hr |
| Jul 16, 4:20 PM EDT | Flash Flood Warning | CTP | 85 min |
| Jul 16, 5:51 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Jul 16, 7:15 PM EDT | Areal Flood Advisory | CTP | 2 hr |
| Jul 16, 10:39 PM EDT | Areal Flood Advisory | CTP | 2 hr |
| Jul 17, 12:00 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jul 17, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 17, 4:38 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Jul 17, 4:50 PM EDT | Severe Thunderstorm Warning | CTP | 55 min |
| Jul 17, 4:56 PM EDT | Areal Flood Advisory | CTP | 61 min |
| Jul 17, 5:44 PM EDT | Severe Thunderstorm Warning | CTP | 61 min |
| Jul 17, 5:56 PM EDT | Flash Flood Warning | CTP | 3 hr |
| Jul 17, 6:54 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 21, 11:59 AM EDT | Special Weather Statement | CTP | 31 min |
| Jul 21, 12:28 PM EDT | Special Weather Statement | CTP | 32 min |
| Jul 29, 2:23 PM EDT | Tornado Watch | SPC | 8 hr |
| Aug 1, 6:27 PM EDT | Severe Thunderstorm Warning | CTP | 33 min |
| Aug 10, 12:55 PM EDT | Heat Advisory | CTP | 30 hr |
| Aug 10, 12:55 PM EDT | Heat Advisory | CTP | 54 hr |
| Aug 11, 3:38 AM EDT | Excessive Heat Warning | CTP | 39 hr |
| Aug 11, 2:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Aug 11, 3:02 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 11, 4:47 PM EDT | Severe Thunderstorm Warning | CTP | 53 min |
| Aug 11, 5:08 PM EDT | Severe Thunderstorm Warning | CTP | 52 min |
| Aug 11, 5:35 PM EDT | Severe Thunderstorm Warning | CTP | 48 min |
| Aug 12, 3:33 AM EDT | Heat Advisory | CTP | 39 hr |
| Aug 12, 12:19 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Aug 12, 1:11 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Aug 12, 9:01 PM EDT | Severe Thunderstorm Warning | CTP | 44 min |
| Aug 12, 9:23 PM EDT | Severe Thunderstorm Warning | CTP | 67 min |
| Aug 12, 9:59 PM EDT | Severe Thunderstorm Warning | CTP | 31 min |
| Aug 12, 10:08 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Aug 12, 10:31 PM EDT | Severe Thunderstorm Warning | CTP | 59 min |
| Aug 13, 3:29 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 13, 3:43 PM EDT | Severe Thunderstorm Warning | CTP | 29 min |
| Aug 13, 7:14 PM EDT | Mesoscale Discussion | SPC | 61 min |
| Aug 17, 2:13 PM EDT | Flash Flood Watch | CTP | 34 hr |
| Aug 18, 10:58 AM EDT | Mesoscale Discussion | SPC | 92 min |
| Aug 18, 11:37 AM EDT | Tornado Watch | SPC | 11 hr |
| Aug 18, 3:29 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Aug 18, 3:56 PM EDT | Severe Thunderstorm Warning | CTP | 34 min |
| Aug 18, 4:57 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Aug 27, 4:34 PM EDT | Areal Flood Advisory | CTP | 2 hr |
| Aug 30, 4:11 AM EDT | Flash Flood Watch | CTP | 67 hr |
| Sep 1, 9:45 AM EDT | Areal Flood Advisory | CTP | 2 hr |
| Sep 1, 12:04 PM EDT | Flash Flood Warning | CTP | 6 hr |
| Sep 1, 5:41 PM EDT | Areal Flood Warning | CTP | 14 hr |
| Sep 8, 5:11 PM EDT | Severe Thunderstorm Warning | CTP | 49 min |
| Sep 8, 5:57 PM EDT | Severe Thunderstorm Warning | CTP | 37 min |
| Sep 13, 5:53 PM EDT | Severe Thunderstorm Watch | SPC | 3 hr |
| Sep 13, 7:07 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Sep 15, 10:33 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 15, 11:55 AM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Sep 15, 2:54 PM EDT | Severe Thunderstorm Warning | CTP | 36 min |
| Sep 15, 3:24 PM EDT | Severe Thunderstorm Warning | CTP | 36 min |
| Sep 15, 4:36 PM EDT | Special Weather Statement | CTP | 24 min |
| Sep 15, 4:38 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Sep 15, 4:46 PM EDT | Areal Flood Advisory | CTP | 89 min |
| Sep 15, 4:58 PM EDT | Special Weather Statement | CTP | 32 min |
| Sep 22, 3:42 AM EDT | Flash Flood Watch | CTP | 33 hr |
| Sep 23, 7:36 AM EDT | Areal Flood Advisory | CTP | 3 hr |
| Sep 23, 10:36 AM EDT | Areal Flood Advisory | CTP | 2 hr |
| Oct 14, 3:10 AM EDT | Dense Fog Advisory | CTP | 6 hr |
| Oct 16, 11:06 AM EDT | Mesoscale Discussion | SPC | 114 min |
| Nov 1, 4:23 AM EDT | Freeze Watch | CTP | 22 hr |
| Nov 2, 2:47 AM EDT | Freeze Warning | CTP | 30 hr |
| Nov 12, 4:49 AM EST | Special Weather Statement | CTP | 26 min |
| Nov 22, 6:26 AM EST | Special Weather Statement | CTP | 79 min |
| Dec 10, 11:15 AM EST | Wind Advisory | CTP | 38 hr |
| Dec 26, 2:58 PM EST | Winter Weather Advisory | CTP | 33 hr |
| Dec 30, 10:09 PM EST | Dense Fog Advisory | CTP | 12 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.