Alert archive / Maryland / Severe Thunderstorm Warnings
Severe Thunderstorm Warnings in Maryland, 2011
303 severe thunderstorm warnings 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 severe thunderstorm warnings reaches back to 1986.
Severe Thunderstorm Warnings by county
Each county as a circle sized by its count in 2011. Tap one for its archive.
- Severe Thunderstorm Warnings
- 303
- Busiest month
- August69 severe thunderstorm warnings
- Busiest day
- August 19, 201120 severe thunderstorm warnings
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
209 of 303 severe thunderstorm warnings covering Maryland in 2011 had a qualifying storm report inside them; 325 of 399 hail, wind and damage reports fell inside a warning, on average 20 minutes after it went out.
Maryland, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Severe thunderstorm warnings | 303 | 209 | 31% | 399 | 81% | 20 min |
Each office's whole area, 2011
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Pittsburgh, PA: severe thunderstorm warnings | 231 | 161 | 30% | 428 | 83% | 22 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 440 | 335 | 24% | 963 | 78% | 18 min |
| NWS Philadelphia/Mount Holly: severe thunderstorm warnings | 307 | 164 | 47% | 361 | 86% | 25 min |
| NWS Wakefield, VA: severe thunderstorm warnings | 241 | 150 | 38% | 386 | 79% | 19 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 | Counties | Lasted |
|---|---|---|---|---|
| Feb 25, 1:25 PM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Montgomery, Prince George's, City of Baltimore | 33 min |
| Feb 25, 1:36 PM EST | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 54 min |
| Feb 25, 1:52 PM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 38 min |
| Feb 25, 1:55 PM EST | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 65 min |
| Feb 25, 2:19 PM EST | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 56 min |
| Feb 28, 9:40 AM EST | Severe Thunderstorm Warning | LWX | Allegany, Frederick, Washington | 50 min |
| Feb 28, 12:39 PM EST | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 32 min |
| Mar 10, 5:34 PM EST | Severe Thunderstorm Warning | LWX | Frederick, Washington | 41 min |
| Mar 10, 6:10 PM EST | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 65 min |
| Mar 10, 7:06 PM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 54 min |
| Mar 21, 7:40 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 27 min |
| Mar 23, 3:47 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 58 min |
| Mar 23, 5:46 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 59 min |
| Mar 23, 6:02 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 45 min |
| Mar 23, 6:29 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 23 min |
| Apr 2, 3:17 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 43 min |
| Apr 5, 4:29 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Montgomery, Prince George's | 51 min |
| Apr 5, 4:38 AM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 67 min |
| Apr 5, 4:40 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Harford, Howard, Montgomery and 2 more | 53 min |
| Apr 5, 5:01 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 74 min |
| Apr 5, 5:28 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 62 min |
| Apr 5, 5:43 AM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico, Worcester | 62 min |
| Apr 5, 10:20 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 40 min |
| Apr 16, 2:58 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 47 min |
| Apr 16, 4:19 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 41 min |
| Apr 16, 4:21 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 39 min |
| Apr 16, 4:59 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Howard, Montgomery, Prince George's | 46 min |
| Apr 16, 6:35 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 40 min |
| Apr 16, 7:01 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 44 min |
| Apr 16, 7:38 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Frederick, Howard, Montgomery and 1 more | 52 min |
| Apr 16, 7:49 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico | 26 min |
| Apr 16, 8:18 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 42 min |
| Apr 16, 8:37 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 23 min |
| Apr 16, 8:38 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 52 min |
| Apr 16, 9:11 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 64 min |
| Apr 24, 3:36 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 39 min |
| Apr 24, 4:07 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery, Prince George's | 38 min |
| Apr 24, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Howard, Montgomery, Prince George's and 1 more | 45 min |
| Apr 24, 4:43 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, City of Baltimore | 47 min |
| Apr 24, 4:56 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 64 min |
| Apr 24, 7:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, City of Baltimore | 32 min |
| Apr 24, 8:06 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 39 min |
| Apr 24, 8:24 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 34 min |
| Apr 26, 8:50 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 22 min |
| Apr 27, 8:19 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 36 min |
| Apr 27, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 19 min |
| Apr 27, 11:47 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 58 min |
| Apr 28, 12:35 AM EDT | Severe Thunderstorm Warning | LWX | Allegany | 70 min |
| Apr 28, 1:29 AM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 35 min |
| Apr 28, 2:59 AM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 62 min |
| Apr 28, 9:39 AM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery | 36 min |
| Apr 28, 10:38 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 52 min |
| Apr 28, 10:54 AM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 66 min |
| Apr 28, 10:56 AM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 49 min |
| Apr 28, 11:09 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 36 min |
| Apr 28, 11:26 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 18 min |
| Apr 28, 11:37 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's | 53 min |
| Apr 28, 11:46 AM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 26 min |
| Apr 28, 5:38 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 39 min |
| May 18, 2:36 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 39 min |
| May 18, 3:12 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 33 min |
| May 18, 3:22 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 47 min |
| May 18, 3:44 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 19 min |
| May 18, 3:58 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 47 min |
| May 18, 4:14 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 46 min |
| May 18, 5:15 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 45 min |
| May 18, 5:56 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 49 min |
| May 19, 4:34 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 41 min |
| May 19, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent | 62 min |
| May 19, 7:22 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Howard, Montgomery | 38 min |
| May 19, 10:14 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 61 min |
| May 23, 5:12 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 48 min |
| May 23, 6:13 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery, Prince George's | 47 min |
| May 23, 8:04 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 56 min |
| May 24, 4:44 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Howard | 19 min |
| May 26, 3:03 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 42 min |
| May 26, 3:40 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 65 min |
| May 26, 4:11 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 49 min |
| May 26, 4:22 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 38 min |
| May 26, 4:41 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 49 min |
| May 26, 5:18 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 26 min |
| May 26, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 22 min |
| May 26, 5:27 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 48 min |
| May 26, 5:54 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 51 min |
| May 26, 6:26 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 45 min |
| May 26, 6:46 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 59 min |
| May 26, 8:50 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 25 min |
| May 26, 11:47 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 58 min |
| May 27, 1:00 AM EDT | Severe Thunderstorm Warning | LWX | Washington | 45 min |
| May 27, 3:13 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 38 min |
| May 27, 5:04 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 15 min |
| May 27, 5:29 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 31 min |
| May 27, 5:33 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 27 min |
| May 27, 6:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 35 min |
| May 27, 6:58 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 32 min |
| May 27, 7:21 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Montgomery, Prince George's | 39 min |
| May 27, 7:29 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 46 min |
| May 27, 7:55 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Frederick, Howard, Montgomery and 1 more | 50 min |
| May 27, 8:08 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 22 min |
| May 27, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Howard | 47 min |
| Jun 1, 3:06 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 54 min |
| Jun 1, 3:07 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 38 min |
| Jun 1, 4:47 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 22 min |
| Jun 1, 4:55 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 26 min |
| Jun 1, 5:32 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 42 min |
| Jun 1, 5:39 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 66 min |
| Jun 1, 6:22 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 38 min |
| Jun 1, 6:39 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 51 min |
| Jun 1, 6:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 46 min |
| Jun 1, 7:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 22 min |
| Jun 9, 6:44 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 46 min |
| Jun 9, 7:31 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 44 min |
| Jun 9, 8:04 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, City of Baltimore | 41 min |
| Jun 9, 8:15 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, City of Baltimore | 45 min |
| Jun 9, 8:40 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 33 min |
| Jun 9, 8:45 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 60 min |
| Jun 9, 11:20 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 40 min |
| Jun 9, 11:26 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 35 min |
| Jun 9, 11:46 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 59 min |
| Jun 10, 12:07 AM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 38 min |
| Jun 10, 12:16 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 59 min |
| Jun 10, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, City of Baltimore | 26 min |
| Jun 11, 3:39 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert | 21 min |
| Jun 11, 4:10 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 50 min |
| Jun 11, 5:23 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 52 min |
| Jun 11, 5:31 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 44 min |
| Jun 11, 8:18 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 42 min |
| Jun 11, 8:54 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 51 min |
| Jun 12, 2:10 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Frederick, Washington | 50 min |
| Jun 12, 2:56 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 34 min |
| Jun 12, 3:12 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 48 min |
| Jun 12, 3:16 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 44 min |
| Jun 12, 3:39 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico, Worcester | 33 min |
| Jun 12, 3:45 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 45 min |
| Jun 12, 3:51 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 54 min |
| Jun 12, 4:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 49 min |
| Jun 12, 4:51 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 39 min |
| Jun 12, 5:00 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 45 min |
| Jun 12, 5:08 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 52 min |
| Jun 12, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 37 min |
| Jun 12, 5:55 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 65 min |
| Jun 12, 6:30 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 45 min |
| Jun 12, 6:50 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 55 min |
| Jun 17, 4:29 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 33 min |
| Jun 17, 6:45 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 45 min |
| Jun 17, 7:23 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 52 min |
| Jun 17, 7:54 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 36 min |
| Jun 21, 6:12 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 48 min |
| Jun 22, 1:05 AM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 55 min |
| Jun 28, 6:22 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Worcester | 38 min |
| Jun 28, 6:34 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 26 min |
| Jul 3, 3:14 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 46 min |
| Jul 3, 3:56 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 49 min |
| Jul 3, 4:03 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 27 min |
| Jul 3, 5:27 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 48 min |
| Jul 3, 5:35 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Howard, Montgomery | 35 min |
| Jul 3, 5:58 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 62 min |
| Jul 3, 6:03 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, Montgomery, Prince George's and 1 more | 72 min |
| Jul 3, 6:36 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 43 min |
| Jul 3, 7:18 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 57 min |
| Jul 3, 7:43 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 62 min |
| Jul 3, 8:15 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 48 min |
| Jul 3, 8:34 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 20 min |
| Jul 7, 4:37 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 38 min |
| Jul 7, 6:04 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 41 min |
| Jul 7, 6:16 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, City of Baltimore | 44 min |
| Jul 7, 8:13 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 14 min |
| Jul 7, 10:01 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 29 min |
| Jul 7, 11:21 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 39 min |
| Jul 8, 4:09 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 51 min |
| Jul 8, 5:10 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 50 min |
| Jul 8, 5:27 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's, Saint Mary's | 48 min |
| Jul 8, 5:53 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 26 min |
| Jul 8, 5:53 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 82 min |
| Jul 8, 6:23 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 82 min |
| Jul 11, 6:40 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 35 min |
| Jul 11, 6:54 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 37 min |
| Jul 11, 7:05 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 40 min |
| Jul 11, 7:10 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 35 min |
| Jul 11, 7:34 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick | 41 min |
| Jul 11, 7:42 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Howard, Montgomery | 48 min |
| Jul 11, 8:06 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 39 min |
| Jul 11, 8:15 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Harford, Howard, Montgomery and 1 more | 45 min |
| Jul 11, 8:46 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Howard, Montgomery, Prince George's | 44 min |
| Jul 11, 8:56 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, City of Baltimore | 34 min |
| Jul 11, 9:11 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 64 min |
| Jul 11, 9:26 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 64 min |
| Jul 11, 9:33 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 57 min |
| Jul 11, 10:03 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 57 min |
| Jul 11, 10:28 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 33 min |
| Jul 13, 3:13 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 47 min |
| Jul 13, 4:02 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 43 min |
| Jul 13, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 45 min |
| Jul 19, 4:41 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 34 min |
| Jul 19, 6:00 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 45 min |
| Jul 19, 6:53 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 38 min |
| Jul 19, 8:02 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 43 min |
| Jul 19, 8:07 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 53 min |
| Jul 22, 2:07 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 38 min |
| Jul 22, 2:07 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 38 min |
| Jul 22, 2:43 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 47 min |
| Jul 22, 3:07 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 38 min |
| Jul 22, 3:07 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 45 min |
| Jul 22, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 45 min |
| Jul 23, 7:09 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 36 min |
| Jul 24, 1:25 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 50 min |
| Jul 24, 2:13 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 36 min |
| Jul 24, 4:06 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's | 54 min |
| Jul 25, 1:28 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 32 min |
| Jul 25, 3:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 46 min |
| Jul 28, 9:26 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 45 min |
| Jul 29, 5:54 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 51 min |
| Jul 29, 6:52 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 38 min |
| Jul 29, 6:58 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 32 min |
| Jul 31, 3:58 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 36 min |
| Aug 1, 4:46 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 48 min |
| Aug 1, 5:12 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 78 min |
| Aug 1, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Montgomery, Prince George's | 51 min |
| Aug 1, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 50 min |
| Aug 1, 5:54 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 51 min |
| Aug 1, 6:03 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 42 min |
| Aug 1, 6:07 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 38 min |
| Aug 1, 6:13 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 47 min |
| Aug 1, 6:31 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert | 22 min |
| Aug 1, 6:41 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 18 min |
| Aug 1, 7:46 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's | 38 min |
| Aug 1, 11:01 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico, Worcester | 29 min |
| Aug 1, 11:32 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 28 min |
| Aug 9, 4:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, City of Baltimore | 35 min |
| Aug 13, 2:13 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 62 min |
| Aug 14, 5:56 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 49 min |
| Aug 14, 7:44 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 42 min |
| Aug 14, 9:15 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 22 min |
| Aug 18, 4:40 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 50 min |
| Aug 18, 5:08 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 52 min |
| Aug 18, 5:14 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 46 min |
| Aug 18, 5:20 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard | 40 min |
| Aug 18, 5:21 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 39 min |
| Aug 18, 5:38 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 36 min |
| Aug 18, 5:48 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 57 min |
| Aug 18, 5:51 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 39 min |
| Aug 18, 5:55 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 50 min |
| Aug 18, 6:11 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 24 min |
| Aug 18, 6:21 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery, Prince George's | 39 min |
| Aug 18, 6:49 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Prince George's, City of Baltimore | 41 min |
| Aug 18, 7:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, City of Baltimore | 47 min |
| Aug 18, 8:30 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 30 min |
| Aug 18, 9:39 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 51 min |
| Aug 18, 10:11 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 49 min |
| Aug 18, 10:36 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 39 min |
| Aug 18, 11:53 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 52 min |
| Aug 19, 2:39 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 36 min |
| Aug 19, 3:16 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 29 min |
| Aug 19, 3:54 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 32 min |
| Aug 19, 4:09 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's | 66 min |
| Aug 19, 4:42 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 63 min |
| Aug 19, 4:53 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 39 min |
| Aug 19, 5:19 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 41 min |
| Aug 19, 5:35 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 55 min |
| Aug 19, 5:54 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 51 min |
| Aug 19, 6:14 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 65 min |
| Aug 19, 6:21 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 69 min |
| Aug 19, 6:36 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, City of Baltimore | 54 min |
| Aug 19, 6:39 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 47 min |
| Aug 19, 6:40 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 50 min |
| Aug 19, 7:13 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 35 min |
| Aug 21, 1:14 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 46 min |
| Aug 21, 1:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Montgomery, Prince George's | 47 min |
| Aug 21, 1:29 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 46 min |
| Aug 21, 1:40 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 50 min |
| Aug 21, 1:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, City of Baltimore | 51 min |
| Aug 21, 2:01 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 59 min |
| Aug 21, 2:39 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 36 min |
| Aug 21, 2:55 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 65 min |
| Aug 21, 3:11 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 49 min |
| Aug 21, 3:12 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 48 min |
| Aug 21, 4:06 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 39 min |
| Aug 21, 4:43 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset | 47 min |
| Aug 21, 4:48 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 27 min |
| Aug 21, 5:09 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 37 min |
| Aug 21, 5:18 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 47 min |
| Aug 21, 5:24 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Worcester | 51 min |
| Aug 25, 4:42 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 48 min |
| Aug 25, 5:20 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 40 min |
| Sep 3, 9:44 AM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 46 min |
| Sep 11, 3:08 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard | 22 min |
| Sep 11, 3:30 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 45 min |
| Sep 11, 10:29 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 46 min |
| Sep 14, 3:18 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 42 min |
| Sep 14, 4:04 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 41 min |
| Sep 14, 4:42 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 48 min |
| Sep 14, 4:44 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 46 min |
| Sep 14, 5:28 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 47 min |
| Sep 14, 5:34 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 41 min |
| Sep 14, 6:01 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 44 min |
| Sep 14, 6:32 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 43 min |
| Sep 14, 6:37 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 38 min |
| Sep 15, 1:20 AM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 55 min |
| Sep 15, 2:12 AM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 48 min |
| Sep 27, 3:20 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 40 min |
| Sep 27, 3:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 65 min |
| Sep 28, 1:58 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's | 62 min |
| Oct 14, 11:17 AM EDT | Severe Thunderstorm Warning | LWX | Harford | 15 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Prince George's County57
- Washington County55
- Anne Arundel County52
- Montgomery County44
- Charles County44
- Baltimore County40
- Frederick County40
- Queen Anne's County33
- Caroline County31
- Howard County30
- Calvert County28
- Talbot County26
- Allegany County26
- Harford County26
- City of Baltimore24
- Kent County23
- Cecil County20
- Carroll County18
- Saint Mary's County17
- Garrett County13
- Worcester County9
- Wicomico County8
- Dorchester County6
- Somerset County6
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.