Alert archive / Pennsylvania / Allegheny County
Weather alerts in Allegheny County, Pennsylvania, 2020
155 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Allegheny County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 155
- Warnings
- 56
- Watches
- 12
- Advisories
- 34
- Busiest month
- July30 alerts
- Busiest day
- March 28, 202013 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 2 tornado warnings covering Allegheny County in 2020 had a tornado report inside them; 0 of 1 tornado reports fell inside a warning.
Allegheny County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 2 | 1 | 50% | 1 | 0% | |
| Severe thunderstorm warnings | 35 | 27 | 23% | 77 | 86% | 18 min |
| Flash flood warnings | 7 | 5 | 29% | 18 | 100% | 54 min |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Pittsburgh, PA: tornado warnings | 10 | 3 | 70% | 8 | 38% | 4 min |
| NWS Pittsburgh, PA: severe thunderstorm warnings | 213 | 143 | 33% | 555 | 83% | 19 min |
| NWS Pittsburgh, PA: flash flood warnings | 24 | 19 | 21% | 49 | 90% | 83 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, 8:10 PM EST | Special Weather Statement | PBZ | 80 min |
| Dec 31, 9:25 PM EST | Special Weather Statement | PBZ | 95 min |
| Jan 8, 10:45 AM EST | Snow Squall Warning | PBZ | 45 min |
| Jan 11, 3:15 AM EST | Wind Advisory | PBZ | 31 hr |
| Jan 11, 4:45 PM EST | Special Weather Statement | PBZ | 60 min |
| Jan 11, 5:20 PM EST | Severe Thunderstorm Warning | PBZ | 25 min |
| Jan 11, 5:41 PM EST | Special Weather Statement | PBZ | 79 min |
| Jan 16, 3:39 PM EST | Special Weather Statement | PBZ | 51 min |
| Jan 17, 2:02 PM EST | Winter Weather Advisory | PBZ | 28 hr |
| Feb 6, 2:58 PM EST | Winter Weather Advisory | PBZ | 28 hr |
| Feb 7, 5:32 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Feb 10, 4:18 PM EST | River Flood Advisory | PBZ | 5 days |
| Feb 13, 9:49 PM EST | Special Weather Statement | PBZ | 86 min |
| Feb 27, 6:09 PM EST | Special Weather Statement | PBZ | 66 min |
| Feb 27, 10:50 PM EST | Special Weather Statement | PBZ | 55 min |
| Feb 27, 11:44 PM EST | Special Weather Statement | PBZ | 61 min |
| Mar 3, 1:22 PM EST | Mesoscale Discussion | SPC | 113 min |
| Mar 20, 7:14 AM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Mar 20, 12:40 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 20, 2:02 PM EDT | Special Weather Statement | PBZ | 43 min |
| Mar 20, 3:32 PM EDT | Areal Flood Warning | PBZ | 3 hr |
| Mar 21, 12:43 AM EDT | River Flood Advisory | PBZ | 19 hr |
| Mar 27, 11:01 AM EDT | River Flood Advisory | PBZ | 4 days |
| Mar 28, 10:22 AM EDT | Severe Thunderstorm Warning | PBZ | 38 min |
| Mar 28, 10:32 AM EDT | Mesoscale Discussion | SPC | 88 min |
| Mar 28, 1:42 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Mar 28, 3:31 PM EDT | Severe Thunderstorm Warning | PBZ | 29 min |
| Mar 28, 3:40 PM EDT | Tornado Warning | PBZ | 35 min |
| Mar 28, 3:56 PM EDT | Severe Thunderstorm Warning | PBZ | 49 min |
| Mar 28, 4:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Mar 28, 4:10 PM EDT | Flash Flood Warning | PBZ | 9 hr |
| Mar 28, 4:13 PM EDT | Severe Thunderstorm Warning | PBZ | 47 min |
| Mar 28, 4:19 PM EDT | Flash Flood Warning | PBZ | 3 hr |
| Mar 28, 4:42 PM EDT | Severe Thunderstorm Warning | PBZ | 48 min |
| Mar 28, 4:54 PM EDT | Severe Thunderstorm Warning | PBZ | 51 min |
| Mar 28, 7:09 PM EDT | Areal Flood Warning | PBZ | 3 hr |
| Mar 28, 9:58 PM EDT | Areal Flood Warning | PBZ | 5 hr |
| Mar 29, 12:32 AM EDT | Areal Flood Warning | PBZ | 8 hr |
| Mar 29, 10:58 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 29, 1:58 PM EDT | Wind Advisory | PBZ | 7 hr |
| Apr 7, 11:40 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Apr 8, 12:47 AM EDT | Severe Thunderstorm Warning | PBZ | 43 min |
| Apr 8, 1:11 AM EDT | Severe Thunderstorm Warning | PBZ | 49 min |
| Apr 8, 1:17 AM EDT | Tornado Warning | PBZ | 6 min |
| Apr 8, 1:22 AM EDT | Severe Thunderstorm Warning | PBZ | 39 min |
| Apr 8, 1:39 AM EDT | Severe Thunderstorm Warning | PBZ | 51 min |
| Apr 11, 2:03 PM EDT | High Wind Watch | PBZ | 24 hr |
| Apr 12, 1:44 PM EDT | Wind Advisory | PBZ | 28 hr |
| Apr 21, 3:44 AM EDT | Freeze Warning | PBZ | 30 hr |
| Apr 29, 9:38 PM EDT | Special Weather Statement | PBZ | 37 min |
| May 1, 6:59 AM EDT | River Flood Advisory | PBZ | 13 hr |
| May 6, 1:01 PM EDT | Frost Advisory | PBZ | 20 hr |
| May 6, 1:01 PM EDT | Freeze Warning | PBZ | 20 hr |
| May 7, 1:13 PM EDT | Freeze Warning | PBZ | 45 hr |
| May 9, 3:17 AM EDT | Freeze Warning | PBZ | 28 hr |
| May 9, 10:12 AM EDT | Special Weather Statement | PBZ | 63 min |
| May 10, 7:28 PM EDT | Special Weather Statement | PBZ | 47 min |
| May 10, 8:19 PM EDT | Special Weather Statement | PBZ | 56 min |
| May 11, 2:53 AM EDT | Freeze Warning | PBZ | 29 hr |
| May 12, 11:46 AM EDT | Frost Advisory | PBZ | 21 hr |
| May 23, 3:51 AM EDT | Dense Fog Advisory | PBZ | 5 hr |
| May 29, 10:47 AM EDT | Mesoscale Discussion | SPC | 118 min |
| May 29, 4:24 PM EDT | Severe Thunderstorm Warning | PBZ | 36 min |
| May 29, 5:18 PM EDT | Special Weather Statement | PBZ | 27 min |
| May 29, 8:37 PM EDT | Areal Flood Advisory | PBZ | 113 min |
| Jun 3, 3:10 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 4, 12:45 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 4, 12:55 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 4, 4:00 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 4, 4:03 PM EDT | Severe Thunderstorm Warning | PBZ | 42 min |
| Jun 4, 4:43 PM EDT | Severe Thunderstorm Warning | PBZ | 77 min |
| Jun 10, 6:32 PM EDT | Severe Thunderstorm Warning | PBZ | 31 min |
| Jun 10, 6:51 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 10, 9:03 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Jun 10, 9:31 PM EDT | Special Weather Statement | PBZ | 29 min |
| Jun 10, 9:52 PM EDT | Severe Thunderstorm Warning | PBZ | 38 min |
| Jun 10, 11:58 PM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Jun 22, 1:58 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 25, 1:36 PM EDT | Special Weather Statement | PBZ | 39 min |
| Jul 7, 4:41 PM EDT | Special Weather Statement | PBZ | 34 min |
| Jul 7, 5:48 PM EDT | Flash Flood Warning | PBZ | 3 hr |
| Jul 8, 3:41 PM EDT | Heat Advisory | PBZ | 28 hr |
| Jul 9, 4:22 PM EDT | Special Weather Statement | PBZ | 23 min |
| Jul 9, 4:37 PM EDT | Severe Thunderstorm Warning | PBZ | 23 min |
| Jul 9, 4:59 PM EDT | Special Weather Statement | PBZ | 31 min |
| Jul 9, 5:10 PM EDT | Areal Flood Advisory | PBZ | 119 min |
| Jul 9, 5:32 PM EDT | Flash Flood Warning | PBZ | 72 min |
| Jul 9, 10:09 PM EDT | Special Weather Statement | PBZ | 36 min |
| Jul 10, 5:07 PM EDT | Severe Thunderstorm Warning | PBZ | 38 min |
| Jul 10, 5:43 PM EDT | Severe Thunderstorm Warning | PBZ | 47 min |
| Jul 10, 5:54 PM EDT | Severe Thunderstorm Warning | PBZ | 51 min |
| Jul 10, 6:12 PM EDT | Severe Thunderstorm Warning | PBZ | 33 min |
| Jul 10, 6:30 PM EDT | Severe Thunderstorm Warning | PBZ | 45 min |
| Jul 10, 6:45 PM EDT | Areal Flood Advisory | PBZ | 36 min |
| Jul 10, 6:49 PM EDT | Areal Flood Advisory | PBZ | 32 min |
| Jul 10, 7:13 PM EDT | Areal Flood Warning | PBZ | 107 min |
| Jul 12, 3:55 PM EDT | Special Weather Statement | PBZ | 35 min |
| Jul 12, 5:42 PM EDT | Special Weather Statement | PBZ | 33 min |
| Jul 12, 5:54 PM EDT | Areal Flood Advisory | PBZ | 58 min |
| Jul 16, 12:18 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 16, 1:20 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 16, 3:13 PM EDT | Special Weather Statement | PBZ | 32 min |
| Jul 16, 3:47 PM EDT | Severe Thunderstorm Warning | PBZ | 28 min |
| Jul 16, 3:51 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jul 18, 1:26 PM EDT | Heat Advisory | PBZ | 28 hr |
| Jul 21, 1:47 PM EDT | Special Weather Statement | PBZ | 43 min |
| Jul 23, 3:31 PM EDT | Special Weather Statement | PBZ | 29 min |
| Jul 23, 3:44 PM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Jul 23, 4:04 PM EDT | Special Weather Statement | PBZ | 26 min |
| Aug 1, 3:57 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 1, 6:59 PM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Aug 4, 3:26 PM EDT | Severe Thunderstorm Warning | PBZ | 34 min |
| Aug 13, 5:45 PM EDT | Special Weather Statement | PBZ | 15 min |
| Aug 13, 6:06 PM EDT | Areal Flood Advisory | PBZ | 54 min |
| Aug 22, 7:12 PM EDT | Areal Flood Advisory | PBZ | 63 min |
| Aug 22, 7:49 PM EDT | Special Weather Statement | PBZ | 26 min |
| Aug 22, 8:03 PM EDT | Areal Flood Advisory | PBZ | 22 min |
| Aug 22, 8:10 PM EDT | Severe Thunderstorm Warning | PBZ | 35 min |
| Aug 22, 8:25 PM EDT | Flash Flood Warning | PBZ | 68 min |
| Aug 22, 8:39 PM EDT | Special Weather Statement | PBZ | 36 min |
| Aug 22, 9:19 PM EDT | Areal Flood Advisory | PBZ | 56 min |
| Aug 25, 6:41 AM EDT | Severe Thunderstorm Warning | PBZ | 19 min |
| Aug 25, 8:06 AM EDT | Special Weather Statement | PBZ | 24 min |
| Aug 25, 12:02 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Aug 25, 1:21 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 25, 2:09 PM EDT | Severe Thunderstorm Warning | PBZ | 51 min |
| Aug 25, 2:34 PM EDT | Severe Thunderstorm Warning | PBZ | 41 min |
| Aug 25, 4:00 PM EDT | Special Weather Statement | PBZ | 30 min |
| Aug 25, 5:01 PM EDT | Severe Thunderstorm Warning | PBZ | 29 min |
| Aug 27, 4:34 PM EDT | Mesoscale Discussion | SPC | 86 min |
| Aug 27, 5:26 PM EDT | Severe Thunderstorm Warning | PBZ | 64 min |
| Aug 27, 5:32 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 27, 6:08 PM EDT | Severe Thunderstorm Warning | PBZ | 52 min |
| Aug 27, 6:41 PM EDT | Severe Thunderstorm Warning | PBZ | 64 min |
| Aug 28, 9:55 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 28, 12:00 PM EDT | Special Weather Statement | PBZ | 30 min |
| Aug 28, 12:38 PM EDT | Flash Flood Warning | PBZ | 6 hr |
| Aug 28, 12:42 PM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Aug 28, 1:14 PM EDT | Flash Flood Warning | PBZ | 6 hr |
| Oct 2, 1:10 PM EDT | Frost Advisory | PBZ | 20 hr |
| Oct 15, 5:04 PM EDT | Freeze Watch | PBZ | 21 hr |
| Oct 16, 1:34 PM EDT | Frost Advisory | PBZ | 19 hr |
| Nov 14, 1:10 PM EST | Wind Advisory | PBZ | 42 hr |
| Nov 15, 1:16 PM EST | Mesoscale Discussion | SPC | 89 min |
| Nov 15, 1:57 PM EST | Severe Thunderstorm Watch | SPC | 4 hr |
| Nov 15, 2:06 PM EST | Severe Thunderstorm Warning | PBZ | 39 min |
| Nov 15, 2:36 PM EST | Severe Thunderstorm Warning | PBZ | 39 min |
| Nov 15, 3:02 PM EST | Severe Thunderstorm Warning | PBZ | 43 min |
| Nov 29, 7:35 PM EST | Winter Weather Advisory | PBZ | 56 hr |
| Dec 15, 3:46 AM EST | Winter Storm Watch | PBZ | 9 hr |
| Dec 15, 3:46 AM EST | Winter Storm Warning | PBZ | 49 hr |
| Dec 16, 3:43 PM EST | Special Weather Statement | PBZ | 2 hr |
| Dec 16, 5:41 PM EST | Special Weather Statement | PBZ | 2 hr |
| Dec 23, 12:39 PM EST | Winter Weather Advisory | PBZ | 48 hr |
| Dec 24, 2:13 PM EST | River Flood Advisory | PBZ | 40 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 | 35 |
| Tornado Warning | 2 |
| Severe Thunderstorm Watch | 9 |
| Mesoscale Discussion | 18 |
| Special Weather Statement | 35 |
| Flooding | |
| Areal Flood Warning | 5 |
| Flash Flood Warning | 7 |
| Areal Flood Advisory | 14 |
| River Flood Advisory | 5 |
| Winter | |
| Snow Squall Warning | 1 |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 4 |
| Heat | |
| Heat Advisory | 2 |
| Cold | |
| Freeze Warning | 5 |
| Freeze Watch | 1 |
| Frost Advisory | 4 |
| Wind and dust | |
| High Wind Watch | 1 |
| Wind Advisory | 4 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.