Alert archive / Pennsylvania / Mesoscale Discussions
Mesoscale Discussions in Pennsylvania, 2011
184 mesoscale discussions in 2011. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of mesoscale discussions reaches back to 2003.
Mesoscale Discussions by county
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Mesoscale Discussions
- 184
- Busiest month
- May31 mesoscale discussions
- Busiest day
- June 9, 20118 mesoscale discussions
Over time
By month
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 | Counties | Lasted |
|---|---|---|---|---|
| Jan 11, 8:00 PM EST | Mesoscale Discussion | SPC | Bucks, Philadelphia | 5 hr |
| Jan 18, 12:29 AM EST | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Dauphin, Delaware and 8 more | 6 hr |
| Jan 18, 3:33 AM EST | Mesoscale Discussion | SPC | Bradford, Carbon, Lackawanna, Luzerne, Monroe, Pike and 4 more | 6 hr |
| Jan 18, 8:01 AM EST | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Lackawanna, Lehigh, Luzerne and 7 more | 4 hr |
| Jan 21, 12:30 AM EST | Mesoscale Discussion | SPC | Carbon, Lehigh, Monroe, Northampton, Pike | 5 hr |
| Jan 26, 7:30 AM EST | Mesoscale Discussion | SPC | Allegheny, Armstrong, Bedford, Blair, Cambria, Franklin and 7 more | 5 hr |
| Jan 26, 11:12 AM EST | Mesoscale Discussion | SPC | Bucks, Montgomery | 4 hr |
| Jan 26, 2:19 PM EST | Mesoscale Discussion | SPC | Adams, Berks, Bucks, Chester, Delaware, Lancaster and 3 more | 6 hr |
| Feb 1, 12:12 AM EST | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 10 more | 5 hr |
| Feb 1, 2:42 AM EST | Mesoscale Discussion | SPC | Berks, Blair, Bradford, Cameron, Carbon, Centre and 30 more | 4 hr |
| Feb 1, 8:39 PM EST | Mesoscale Discussion | SPC | Adams, Armstrong, Bedford, Berks, Blair, Bucks and 44 more | 6 hr |
| Feb 20, 7:46 PM EST | Mesoscale Discussion | SPC | Armstrong, Blair, Bradford, Butler, Cameron, Centre and 24 more | 4 hr |
| Feb 20, 11:50 PM EST | Mesoscale Discussion | SPC | Bradford, Butler, Cambria, Cameron, Carbon, Centre and 29 more | 5 hr |
| Feb 21, 5:58 PM EST | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Bedford, Blair, Cambria and 12 more | 4 hr |
| Feb 21, 6:33 PM EST | Mesoscale Discussion | SPC | Fayette, Greene | 5 hr |
| Feb 25, 2:46 AM EST | Mesoscale Discussion | SPC | Bradford, Cameron, Crawford, Elk, Erie, Forest and 6 more | 4 hr |
| Feb 25, 11:36 AM EST | Mesoscale Discussion | SPC | Chester, Delaware, Philadelphia | 84 min |
| Feb 28, 5:31 AM EST | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Lawrence, Washington | 29 min |
| Mar 6, 12:59 PM EST | Mesoscale Discussion | SPC | Bradford, Carbon, Columbia, Dauphin, Huntingdon, Juniata and 15 more | 4 hr |
| Mar 6, 7:32 PM EST | Mesoscale Discussion | SPC | Bradford, Lackawanna, Susquehanna, Wayne, Wyoming | 4 hr |
| Mar 23, 3:32 AM EDT | Mesoscale Discussion | SPC | Bradford, Carbon, Columbia, Lackawanna, Lehigh, Luzerne and 11 more | 4 hr |
| Mar 23, 3:54 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Butler and 10 more | 96 min |
| Apr 4, 4:12 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Washington, Westmoreland | 63 min |
| Apr 4, 6:00 PM EDT | Mesoscale Discussion | SPC | Allegheny, Fayette, Greene, Indiana, Somerset, Washington and 1 more | 90 min |
| Apr 5, 5:03 AM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Delaware, Lancaster and 5 more | 27 min |
| Apr 5, 6:25 AM EDT | Mesoscale Discussion | SPC | Bucks, Delaware, Philadelphia | 2 hr |
| Apr 11, 12:24 PM EDT | Mesoscale Discussion | SPC | Fayette, Greene, Somerset | 36 min |
| Apr 11, 6:43 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Columbia, Cumberland and 22 more | 62 min |
| Apr 16, 10:43 AM EDT | Mesoscale Discussion | SPC | Fayette, Greene, Washington | 62 min |
| Apr 16, 1:34 PM EDT | Mesoscale Discussion | SPC | Beaver, Crawford, Lawrence, Mercer, Washington | 116 min |
| Apr 16, 2:05 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Cumberland, Dauphin, Franklin, Fulton and 6 more | 55 min |
| Apr 16, 4:29 PM EDT | Mesoscale Discussion | SPC | Adams, Chester, Franklin, Fulton, Lancaster, York | 31 min |
| Apr 16, 6:38 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Chester, Cumberland, Dauphin, Delaware and 13 more | 97 min |
| Apr 16, 9:58 PM EDT | Mesoscale Discussion | SPC | Berks, Chester, Delaware | 62 min |
| Apr 20, 3:20 AM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 10 more | 85 min |
| Apr 20, 3:45 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bradford, Cambria and 30 more | 30 min |
| Apr 24, 2:12 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bucks, Chester, Cumberland, Dauphin and 10 more | 93 min |
| Apr 24, 6:10 PM EDT | Mesoscale Discussion | SPC | Adams, Chester, Delaware, Lancaster, Montgomery, Philadelphia and 1 more | 65 min |
| Apr 25, 1:52 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Bradford, Butler and 34 more | 83 min |
| Apr 25, 6:00 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Butler, Cambria and 22 more | 60 min |
| Apr 26, 1:18 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Bedford, Blair, Bradford, Butler and 35 more | 57 min |
| Apr 26, 4:12 PM EDT | Mesoscale Discussion | SPC | Bedford, Blair, Bradford, Cambria, Cameron, Centre and 30 more | 63 min |
| Apr 26, 6:51 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Blair, Bradford, Cambria, Cameron and 29 more | 54 min |
| Apr 27, 1:24 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Butler and 28 more | 96 min |
| Apr 27, 3:55 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Chester, Delaware, Lehigh, Monroe and 4 more | 65 min |
| Apr 27, 6:50 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Blair, Bradford, Cameron, Carbon and 33 more | 55 min |
| Apr 27, 9:03 PM EDT | Mesoscale Discussion | SPC | Adams, Bradford, Columbia, Cumberland, Dauphin, Juniata and 9 more | 57 min |
| Apr 27, 10:45 PM EDT | Mesoscale Discussion | SPC | Blair, Bradford, Cambria, Carbon, Centre, Clinton and 23 more | 60 min |
| Apr 28, 2:20 AM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bradford, Carbon and 31 more | 55 min |
| Apr 28, 3:32 AM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Bucks, Carbon, Chester and 25 more | 28 min |
| Apr 28, 6:21 AM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Delaware, Lackawanna and 7 more | 54 min |
| Apr 28, 11:49 AM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Lehigh, Monroe, Montgomery and 4 more | 56 min |
| May 3, 2:27 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bradford, Carbon, Columbia and 27 more | 2 hr |
| May 3, 6:51 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bradford, Carbon, Centre and 30 more | 84 min |
| May 12, 10:30 AM EDT | Mesoscale Discussion | SPC | Greene | 90 min |
| May 12, 6:52 PM EDT | Mesoscale Discussion | SPC | Beaver, Greene, Lawrence, Mercer | |
| May 17, 6:27 PM EDT | Mesoscale Discussion | SPC | Adams, Cumberland, Franklin, Fulton, Lancaster, York | 2 hr |
| May 18, 11:55 AM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Beaver, Bedford, Blair, Cambria and 8 more | 65 min |
| May 18, 2:34 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Columbia, Lackawanna, Lebanon and 12 more | 56 min |
| May 18, 3:08 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Berks and 43 more | 67 min |
| May 18, 6:01 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Beaver, Bedford, Butler, Fayette and 7 more | 89 min |
| May 19, 10:47 AM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Bucks, Carbon, Lackawanna, Lehigh and 9 more | 88 min |
| May 19, 2:17 PM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Bucks, Carbon, Chester, Columbia and 23 more | 58 min |
| May 19, 5:02 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Dauphin, Delaware and 12 more | 58 min |
| May 23, 8:25 AM EDT | Mesoscale Discussion | SPC | Crawford, Erie | 65 min |
| May 23, 10:33 AM EDT | Mesoscale Discussion | SPC | Adams, Armstrong, Bedford, Blair, Cambria, Cameron and 21 more | 87 min |
| May 23, 2:33 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Blair, Cambria, Centre, Clearfield and 12 more | 87 min |
| May 23, 4:40 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Chester, Columbia and 22 more | 95 min |
| May 23, 8:07 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 9 more | 83 min |
| May 24, 1:34 PM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Bucks, Carbon, Columbia, Lackawanna and 11 more | 116 min |
| May 25, 4:45 PM EDT | Mesoscale Discussion | SPC | Beaver, Butler, Lawrence, Mercer | 60 min |
| May 25, 8:14 PM EDT | Mesoscale Discussion | SPC | Crawford, Lawrence, Mercer | 2 hr |
| May 26, 2:37 AM EDT | Mesoscale Discussion | SPC | Beaver, Lawrence | 83 min |
| May 26, 11:55 AM EDT | Mesoscale Discussion | SPC | Bradford, Clinton, Columbia, Dauphin, Juniata, Lackawanna and 13 more | 95 min |
| May 26, 5:49 PM EDT | Mesoscale Discussion | SPC | Adams, Armstrong, Bedford, Blair, Bradford, Cambria and 41 more | 56 min |
| May 26, 8:54 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Columbia, Cumberland and 21 more | 66 min |
| May 27, 12:24 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Columbia, Cumberland and 25 more | 96 min |
| May 27, 6:14 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bradford, Carbon, Centre and 31 more | 2 hr |
| May 29, 6:05 PM EDT | Mesoscale Discussion | SPC | Crawford, Erie, Mercer, Warren | 25 min |
| May 29, 7:28 PM EDT | Mesoscale Discussion | SPC | Clarion, Crawford, Elk, Erie, Forest, McKean and 3 more | 62 min |
| May 29, 9:47 PM EDT | Mesoscale Discussion | SPC | Armstrong, Butler, Cameron, Centre, Clarion, Clearfield and 11 more | 58 min |
| May 30, 3:46 AM EDT | Mesoscale Discussion | SPC | Bucks, Carbon, Columbia, Lackawanna, Lehigh, Luzerne and 8 more | 119 min |
| May 31, 4:07 PM EDT | Mesoscale Discussion | SPC | Crawford, Mercer, Venango | 113 min |
| Jun 1, 5:58 AM EDT | Mesoscale Discussion | SPC | Susquehanna | 2 hr |
| Jun 1, 9:38 AM EDT | Mesoscale Discussion | SPC | Bradford, Cameron, McKean, Potter, Tioga | 37 min |
| Jun 4, 8:58 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Washington | 2 hr |
| Jun 7, 5:29 AM EDT | Mesoscale Discussion | SPC | Crawford, Erie, Lawrence, Mercer, Venango | 3 hr |
| Jun 7, 8:22 AM EDT | Mesoscale Discussion | SPC | Beaver, Butler, Crawford, Erie, Lawrence, Mercer and 1 more | 113 min |
| Jun 7, 10:32 AM EDT | Mesoscale Discussion | SPC | Greene | 88 min |
| Jun 8, 7:45 PM EDT | Mesoscale Discussion | SPC | Susquehanna, Wayne | 90 min |
| Jun 9, 3:29 AM EDT | Mesoscale Discussion | SPC | Cameron, Crawford, Elk, Erie, Forest, McKean and 5 more | 2 hr |
| Jun 9, 8:13 AM EDT | Mesoscale Discussion | SPC | Clarion, Crawford, Elk, Erie, Forest, Lawrence and 6 more | 2 hr |
| Jun 9, 10:36 AM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Bradford, Butler and 31 more | 84 min |
| Jun 9, 11:33 AM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Bedford, Blair, Bradford, Butler and 37 more | 57 min |
| Jun 9, 1:45 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Chester, Delaware, Lancaster, Lebanon and 6 more | 90 min |
| Jun 9, 3:18 PM EDT | Mesoscale Discussion | SPC | Bradford, Carbon, Columbia, Lackawanna, Luzerne, Monroe and 7 more | 87 min |
| Jun 9, 6:17 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Blair, Cambria, Cumberland, Fayette and 8 more | 58 min |
| Jun 9, 7:17 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Columbia, Delaware and 13 more | 58 min |
| Jun 10, 5:28 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bucks, Carbon and 24 more | 92 min |
| Jun 12, 12:03 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Cumberland, Franklin, Fulton, Huntingdon and 4 more | 87 min |
| Jun 16, 6:01 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Armstrong, Beaver, Bedford, Blair and 40 more | 89 min |
| Jun 22, 2:03 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Carbon, Chester, Columbia and 24 more | 117 min |
| Jun 22, 5:40 PM EDT | Mesoscale Discussion | SPC | Bucks | 95 min |
| Jun 23, 10:04 AM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 116 min |
| Jun 23, 12:33 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 9 more | 117 min |
| Jun 23, 3:27 PM EDT | Mesoscale Discussion | SPC | Armstrong, Blair, Bradford, Butler, Cambria, Cameron and 28 more | 2 hr |
| Jun 24, 11:42 AM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Bucks, Carbon, Chester, Columbia and 27 more | 3 hr |
| Jun 24, 4:13 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Northampton, Philadelphia and 1 more | 92 min |
| Jun 28, 1:19 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Bradford and 36 more | 86 min |
| Jun 28, 6:42 PM EDT | Mesoscale Discussion | SPC | Bradford, Columbia, Lackawanna, Luzerne, Lycoming, Montour and 5 more | 93 min |
| Jul 2, 9:01 PM EDT | Mesoscale Discussion | SPC | Armstrong, Beaver, Butler, Clarion, Crawford, Erie and 6 more | 59 min |
| Jul 3, 3:22 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Fayette, Franklin, Fulton, Greene and 1 more | 53 min |
| Jul 4, 1:54 PM EDT | Mesoscale Discussion | SPC | Fayette, Greene, Somerset | 96 min |
| Jul 6, 1:04 PM EDT | Mesoscale Discussion | SPC | Bradford, Susquehanna, Tioga | 56 min |
| Jul 6, 6:03 PM EDT | Mesoscale Discussion | SPC | Bradford, Lackawanna, Lycoming, Pike, Sullivan, Susquehanna and 2 more | 87 min |
| Jul 8, 11:44 AM EDT | Mesoscale Discussion | SPC | Adams, Berks, Blair, Bradford, Bucks, Cameron and 37 more | 61 min |
| Jul 8, 5:52 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Delaware, Lackawanna and 12 more | 83 min |
| Jul 11, 1:42 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Fayette, Greene, Lawrence, Washington | 93 min |
| Jul 11, 3:43 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Crawford, Fayette and 6 more | 92 min |
| Jul 11, 5:54 PM EDT | Mesoscale Discussion | SPC | Bedford, Blair, Cambria, Centre, Clearfield, Elk and 5 more | 96 min |
| Jul 11, 7:44 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Cumberland, Dauphin, Franklin, Fulton and 4 more | 61 min |
| Jul 18, 1:18 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Elk and 8 more | 117 min |
| Jul 18, 8:02 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Butler, Crawford, Lawrence, Mercer | 58 min |
| Jul 22, 3:17 PM EDT | Mesoscale Discussion | SPC | Adams, Allegheny, Beaver, Bedford, Cambria, Cumberland and 10 more | 58 min |
| Jul 22, 5:19 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Cambria, Clarion and 9 more | 56 min |
| Jul 22, 8:13 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Butler and 14 more | 62 min |
| Jul 25, 11:12 AM EDT | Mesoscale Discussion | SPC | Butler, Cameron, Clarion, Crawford, Elk, Forest and 8 more | 63 min |
| Jul 25, 1:12 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Chester, Delaware, Lancaster, Montgomery and 2 more | 2 hr |
| Jul 25, 3:16 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bradford, Butler, Cameron and 22 more | 59 min |
| Jul 25, 5:42 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bucks, Cambria and 25 more | 63 min |
| Jul 26, 3:39 PM EDT | Mesoscale Discussion | SPC | Bradford, Susquehanna, Tioga | 66 min |
| Jul 26, 5:24 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Dauphin, Lebanon, Lehigh and 6 more | 66 min |
| Jul 26, 6:17 PM EDT | Mesoscale Discussion | SPC | Wayne | 58 min |
| Jul 28, 3:43 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Butler, Fayette, Greene, Lawrence and 2 more | 62 min |
| Jul 28, 7:02 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Butler, Cambria and 8 more | 58 min |
| Jul 29, 3:31 AM EDT | Mesoscale Discussion | SPC | Crawford, Erie, McKean, Warren | 89 min |
| Jul 29, 12:57 PM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Bucks, Carbon, Clinton, Columbia and 18 more | 2 hr |
| Jul 29, 2:06 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Butler and 9 more | 84 min |
| Jul 29, 4:40 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bradford, Bucks and 43 more | 95 min |
| Aug 1, 3:47 AM EDT | Mesoscale Discussion | SPC | Crawford, Erie, Warren | 58 min |
| Aug 1, 8:01 AM EDT | Mesoscale Discussion | SPC | Bradford, Cameron, Clarion, Crawford, Elk, Erie and 7 more | 89 min |
| Aug 1, 12:07 PM EDT | Mesoscale Discussion | SPC | Bradford, Cameron, Lackawanna, Lycoming, McKean, Potter and 5 more | 53 min |
| Aug 1, 1:06 PM EDT | Mesoscale Discussion | SPC | Beaver, Lawrence | 24 min |
| Aug 1, 2:15 PM EDT | Mesoscale Discussion | SPC | Carbon, Columbia, Lackawanna, Lehigh, Luzerne, Monroe and 8 more | 90 min |
| Aug 1, 3:22 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bucks, Chester, Cumberland and 19 more | 83 min |
| Aug 1, 6:18 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 57 min |
| Aug 7, 3:53 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Blair, Bradford, Carbon, Centre and 25 more | 67 min |
| Aug 7, 7:36 PM EDT | Mesoscale Discussion | SPC | Greene | 84 min |
| Aug 9, 12:48 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 57 min |
| Aug 9, 3:05 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bradford, Bucks, Carbon, Centre and 31 more | 55 min |
| Aug 9, 7:07 PM EDT | Mesoscale Discussion | SPC | Bucks, Carbon, Chester, Delaware, Lackawanna, Lehigh and 6 more | 83 min |
| Aug 9, 8:31 PM EDT | Mesoscale Discussion | SPC | Beaver, Crawford, Lawrence, Mercer, Venango | 89 min |
| Aug 13, 2:07 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Centre, Chester and 20 more | 113 min |
| Aug 18, 6:39 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 96 min |
| Aug 19, 12:43 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Blair, Bucks, Carbon, Chester and 31 more | 62 min |
| Aug 19, 6:42 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 63 min |
| Aug 19, 7:44 PM EDT | Mesoscale Discussion | SPC | Delaware, Philadelphia | 61 min |
| Aug 20, 4:37 PM EDT | Mesoscale Discussion | SPC | Erie | 83 min |
| Aug 21, 11:54 AM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bucks, Carbon, Chester and 24 more | 2 hr |
| Aug 21, 7:12 PM EDT | Mesoscale Discussion | SPC | Adams, Berks, Bucks, Carbon, Chester, Columbia and 23 more | 63 min |
| Aug 24, 11:48 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Cameron, Clarion and 17 more | 87 min |
| Aug 25, 2:31 AM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Bradford, Butler and 20 more | 119 min |
| Aug 27, 7:31 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Montgomery, Philadelphia | 89 min |
| Aug 28, 12:30 AM EDT | Mesoscale Discussion | SPC | Bucks, Delaware, Montgomery, Northampton, Philadelphia | 90 min |
| Sep 4, 1:33 PM EDT | Mesoscale Discussion | SPC | Bedford, Blair, Bradford, Cambria, Cameron, Centre and 28 more | 87 min |
| Sep 4, 6:06 PM EDT | Mesoscale Discussion | SPC | Bradford, Clinton, Columbia, Lackawanna, Luzerne, Lycoming and 9 more | 54 min |
| Sep 4, 8:35 PM EDT | Mesoscale Discussion | SPC | Bradford, Clinton, Columbia, Lackawanna, Luzerne, Lycoming and 10 more | 55 min |
| Sep 7, 3:36 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Chester, Delaware, Montgomery, Philadelphia | 84 min |
| Sep 11, 6:38 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Chester, Cumberland, Dauphin, Delaware and 8 more | 97 min |
| Sep 13, 7:00 PM EDT | Mesoscale Discussion | SPC | Crawford, Erie, Forest, McKean, Mercer, Venango and 1 more | 60 min |
| Sep 14, 3:22 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Carbon, Chester, Cumberland and 11 more | 53 min |
| Sep 25, 6:34 PM EDT | Mesoscale Discussion | SPC | Allegheny, Beaver, Butler, Crawford, Greene, Lawrence and 2 more | 86 min |
| Sep 26, 2:16 PM EDT | Mesoscale Discussion | SPC | Beaver, Crawford, Greene, Lawrence, Mercer, Washington | 59 min |
| Sep 28, 4:45 PM EDT | Mesoscale Discussion | SPC | Berks, Bucks, Carbon, Chester, Columbia, Dauphin and 13 more | 60 min |
| Sep 29, 11:22 AM EDT | Mesoscale Discussion | SPC | Carbon, Monroe, Northampton, Pike | 83 min |
| Oct 29, 12:34 AM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Cumberland, Franklin, Fulton, Huntingdon and 3 more | 6 hr |
| Oct 29, 7:36 AM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Bradford, Carbon, Columbia and 24 more | 5 hr |
| Oct 29, 1:01 PM EDT | Mesoscale Discussion | SPC | Berks, Bradford, Carbon, Columbia, Dauphin, Juniata and 18 more | 5 hr |
| Nov 14, 4:38 PM EST | Mesoscale Discussion | SPC | Beaver, Butler, Crawford, Erie, Lawrence, Mercer and 1 more | 2 hr |
| Nov 14, 6:03 PM EST | Mesoscale Discussion | SPC | Armstrong, Bradford, Cameron, Clarion, Clearfield, Clinton and 9 more | 117 min |
| Nov 14, 8:41 PM EST | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Butler, Clarion, Clearfield and 5 more | 2 hr |
| Dec 7, 2:44 PM EST | Mesoscale Discussion | SPC | Bedford, Fayette, Somerset | 3 hr |
| Dec 7, 6:21 PM EST | Mesoscale Discussion | SPC | Bradford, Carbon, Columbia, Cumberland, Dauphin, Franklin and 20 more | 4 hr |
| Dec 7, 10:25 PM EST | Mesoscale Discussion | SPC | Lackawanna, Pike, Wayne | 4 hr |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Lackawanna County59
- Montour County59
- Bradford County58
- Wayne County57
- Columbia County57
- Carbon County56
- Luzerne County56
- Schuylkill County55
- Susquehanna County55
- Juniata County55
- Lycoming County55
- Perry County55
- Sullivan County54
- Wyoming County54
- Northumberland County54
- Snyder County54
- Dauphin County53
- Monroe County53
- Pike County53
- Berks County52
- York County52
- Franklin County52
- Union County52
- Cumberland County51
- Huntingdon County50
- Adams County50
- Lebanon County49
- Lehigh County49
- Northampton County49
- Bucks County48
- Chester County48
- Fulton County48
- Lancaster County47
- Mifflin County47
- Montgomery County46
- Tioga County45
- Bedford County44
- Philadelphia County43
- Mercer County43
- Delaware County42
27 more counties
- Beaver County42
- Lawrence County41
- Blair County39
- Butler County38
- Clinton County38
- Allegheny County37
- Indiana County37
- Washington County37
- Venango County36
- Greene County35
- Somerset County35
- Westmoreland County35
- Crawford County35
- Armstrong County34
- Cambria County34
- Centre County34
- Clarion County33
- Potter County33
- Fayette County32
- Cameron County32
- Forest County31
- Elk County31
- McKean County30
- Clearfield County28
- Jefferson County27
- Warren County27
- Erie County22
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20102012
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.