Alert archive / Maryland / Severe Thunderstorm Warnings
Severe Thunderstorm Warnings in Maryland, 2009
196 severe thunderstorm warnings in 2009. 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 2009. Tap one for its archive.
- Severe Thunderstorm Warnings
- 196
- Busiest month
- June78 severe thunderstorm warnings
- Busiest day
- June 9, 200927 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.
96 of 196 severe thunderstorm warnings covering Maryland in 2009 had a qualifying storm report inside them; 161 of 199 hail, wind and damage reports fell inside a warning, on average 21 minutes after it went out.
Maryland, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Severe thunderstorm warnings | 196 | 96 | 51% | 199 | 81% | 21 min |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Wakefield, VA: severe thunderstorm warnings | 290 | 137 | 53% | 332 | 80% | 19 min |
| NWS Pittsburgh, PA: severe thunderstorm warnings | 115 | 66 | 43% | 119 | 78% | 25 min |
| NWS Philadelphia/Mount Holly: severe thunderstorm warnings | 235 | 113 | 52% | 260 | 82% | 26 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 216 | 113 | 48% | 277 | 86% | 21 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 11, 7:26 PM EST | Severe Thunderstorm Warning | PBZ | Garrett | 64 min |
| Feb 11, 7:31 PM EST | Severe Thunderstorm Warning | LWX | Allegany | 74 min |
| Feb 11, 8:17 PM EST | Severe Thunderstorm Warning | LWX | Allegany | 58 min |
| Feb 11, 8:35 PM EST | Severe Thunderstorm Warning | LWX | Allegany, Washington | 70 min |
| Feb 11, 9:33 PM EST | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 43 min |
| Feb 11, 10:07 PM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Harford, Howard, Montgomery and 2 more | 49 min |
| Mar 29, 4:20 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 22 min |
| Mar 29, 5:31 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 29 min |
| Mar 29, 5:45 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 25 min |
| Mar 29, 6:11 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 64 min |
| Apr 6, 10:45 AM EDT | Severe Thunderstorm Warning | AKQ | Wicomico, Worcester | 45 min |
| Apr 20, 6:42 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico | 63 min |
| Apr 20, 8:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 33 min |
| Apr 20, 9:33 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's | 34 min |
| Apr 21, 5:34 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 26 min |
| Apr 21, 6:22 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 38 min |
| Apr 21, 6:24 PM EDT | Severe Thunderstorm Warning | LWX | Howard, Montgomery | 36 min |
| Apr 21, 6:31 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 44 min |
| Apr 21, 6:49 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Saint Mary's | 41 min |
| Apr 21, 7:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 10 min |
| Apr 21, 7:31 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 44 min |
| Apr 21, 7:38 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico | 52 min |
| Apr 21, 7:51 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 39 min |
| Apr 22, 4:30 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 34 min |
| Apr 25, 7:47 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 47 min |
| Apr 26, 2:06 AM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico, Worcester | 54 min |
| May 4, 2:29 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 46 min |
| May 6, 11:03 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 24 min |
| May 7, 1:13 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 43 min |
| May 9, 6:41 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 49 min |
| May 9, 7:20 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico, Worcester | 55 min |
| May 23, 5:34 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 26 min |
| May 25, 3:43 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 47 min |
| May 28, 2:51 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 39 min |
| May 29, 1:06 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 24 min |
| May 29, 2:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Montgomery, Prince George's, City of Baltimore | 51 min |
| May 29, 3:15 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 27 min |
| May 29, 3:22 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 68 min |
| May 29, 4:45 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 50 min |
| May 29, 5:21 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 39 min |
| May 29, 5:32 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 58 min |
| May 29, 5:39 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 40 min |
| May 29, 5:47 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 10 min |
| May 29, 5:52 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 31 min |
| May 29, 7:18 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 42 min |
| May 29, 7:41 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico, Worcester | 49 min |
| May 29, 7:51 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 54 min |
| May 29, 8:06 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 24 min |
| Jun 2, 4:40 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 50 min |
| Jun 2, 4:59 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 51 min |
| Jun 2, 5:30 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 56 min |
| Jun 2, 6:08 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 67 min |
| Jun 2, 6:40 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 65 min |
| Jun 2, 7:00 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 30 min |
| Jun 2, 7:16 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset | 59 min |
| Jun 2, 9:07 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 38 min |
| Jun 2, 9:37 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 29 min |
| Jun 3, 5:46 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico, Worcester | 44 min |
| Jun 3, 6:01 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico | 44 min |
| Jun 3, 6:05 PM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 40 min |
| Jun 3, 6:19 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 41 min |
| Jun 3, 6:21 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 54 min |
| Jun 3, 6:44 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 46 min |
| Jun 3, 7:18 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Montgomery, Prince George's | 42 min |
| Jun 9, 5:47 AM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 28 min |
| Jun 9, 6:02 AM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 43 min |
| Jun 9, 6:51 AM EDT | Severe Thunderstorm Warning | LWX | Charles | 39 min |
| Jun 9, 8:24 AM EDT | Severe Thunderstorm Warning | AKQ | Wicomico | 39 min |
| Jun 9, 1:14 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 61 min |
| Jun 9, 2:03 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 57 min |
| Jun 9, 2:28 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 47 min |
| Jun 9, 2:44 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 46 min |
| Jun 9, 2:52 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 38 min |
| Jun 9, 3:04 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 41 min |
| Jun 9, 3:05 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 28 min |
| Jun 9, 3:09 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 51 min |
| Jun 9, 3:29 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 61 min |
| Jun 9, 3:43 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 47 min |
| Jun 9, 3:51 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Washington | 39 min |
| Jun 9, 4:19 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 56 min |
| Jun 9, 4:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford, Howard, Montgomery and 2 more | 49 min |
| Jun 9, 4:39 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 39 min |
| Jun 9, 4:52 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 53 min |
| Jun 9, 4:59 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, Montgomery, Prince George's and 1 more | 61 min |
| Jun 9, 5:13 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Calvert, Charles, Howard, Montgomery and 2 more | 62 min |
| Jun 9, 5:13 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 92 min |
| Jun 9, 5:18 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, Howard, City of Baltimore | 57 min |
| Jun 9, 5:46 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 59 min |
| Jun 9, 6:15 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 60 min |
| Jun 9, 6:17 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 43 min |
| Jun 9, 6:45 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 45 min |
| Jun 10, 5:42 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford | 48 min |
| Jun 10, 6:25 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 50 min |
| Jun 10, 6:33 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Howard | 42 min |
| Jun 10, 6:59 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 46 min |
| Jun 11, 5:58 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 47 min |
| Jun 13, 3:02 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 58 min |
| Jun 13, 4:52 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 53 min |
| Jun 15, 2:52 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 37 min |
| Jun 17, 9:00 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 60 min |
| Jun 17, 9:22 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 53 min |
| Jun 17, 10:17 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 58 min |
| Jun 17, 11:27 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 38 min |
| Jun 18, 12:06 AM EDT | Severe Thunderstorm Warning | LWX | Allegany | 39 min |
| Jun 18, 2:56 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 49 min |
| Jun 18, 3:46 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 59 min |
| Jun 20, 3:24 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 53 min |
| Jun 20, 3:57 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's, Talbot | 66 min |
| Jun 20, 4:23 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 37 min |
| Jun 20, 4:27 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 53 min |
| Jun 20, 5:01 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 59 min |
| Jun 20, 7:05 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 25 min |
| Jun 26, 3:30 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 45 min |
| Jun 26, 4:15 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 45 min |
| Jun 26, 5:01 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 35 min |
| Jun 26, 5:02 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 43 min |
| Jun 26, 6:01 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 44 min |
| Jun 26, 6:13 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 36 min |
| Jun 26, 6:35 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 40 min |
| Jun 26, 7:15 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 45 min |
| Jun 26, 7:50 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 40 min |
| Jun 26, 8:40 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 37 min |
| Jun 26, 8:42 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 14 min |
| Jun 26, 9:10 PM EDT | Severe Thunderstorm Warning | PHI | Queen Anne's, Talbot | 24 min |
| Jun 26, 9:11 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 49 min |
| Jun 30, 2:31 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 44 min |
| Jul 1, 8:09 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 38 min |
| Jul 1, 9:40 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset | 50 min |
| Jul 11, 2:55 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 21 min |
| Jul 17, 6:10 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 80 min |
| Jul 21, 5:31 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 44 min |
| Jul 21, 9:24 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 51 min |
| Jul 23, 4:13 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 47 min |
| Jul 24, 5:54 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 48 min |
| Jul 24, 6:28 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 62 min |
| Jul 24, 6:46 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 74 min |
| Jul 24, 7:06 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 24 min |
| Jul 25, 7:19 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 41 min |
| Jul 25, 9:41 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 64 min |
| Jul 25, 10:29 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 61 min |
| Jul 26, 3:35 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 55 min |
| Jul 26, 3:55 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico | 50 min |
| Jul 26, 4:19 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 44 min |
| Jul 26, 4:37 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 53 min |
| Jul 26, 5:13 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset | 47 min |
| Jul 26, 5:39 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Howard | 50 min |
| Jul 26, 5:55 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 65 min |
| Jul 26, 6:19 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 43 min |
| Jul 26, 7:04 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 29 min |
| Jul 26, 7:05 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 70 min |
| Jul 27, 3:32 PM EDT | Severe Thunderstorm Warning | AKQ | Worcester | 41 min |
| Jul 29, 4:41 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 23 min |
| Jul 29, 4:43 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico, Worcester | 23 min |
| Jul 31, 1:58 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 47 min |
| Jul 31, 2:06 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Montgomery, Prince George's, City of Baltimore | 39 min |
| Jul 31, 2:10 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 15 min |
| Jul 31, 2:40 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Carroll, Harford, Howard, Montgomery and 1 more | 50 min |
| Jul 31, 3:10 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent | 65 min |
| Jul 31, 3:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Prince George's | 15 min |
| Jul 31, 3:40 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 65 min |
| Jul 31, 3:54 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's | 53 min |
| Jul 31, 4:27 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Wicomico, Worcester | 48 min |
| Aug 2, 7:12 AM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 67 min |
| Aug 2, 10:08 AM EDT | Severe Thunderstorm Warning | PHI | Cecil | 67 min |
| Aug 2, 10:39 AM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 96 min |
| Aug 2, 12:10 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Talbot | 65 min |
| Aug 2, 12:32 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 43 min |
| Aug 2, 12:42 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 48 min |
| Aug 9, 5:53 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 82 min |
| Aug 9, 6:29 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 45 min |
| Aug 9, 6:48 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's | 72 min |
| Aug 10, 11:06 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 54 min |
| Aug 11, 8:09 PM EDT | Severe Thunderstorm Warning | PHI | Queen Anne's, Talbot | 66 min |
| Aug 11, 8:42 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 48 min |
| Aug 11, 9:04 PM EDT | Severe Thunderstorm Warning | PHI | Talbot | 26 min |
| Aug 18, 5:10 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 32 min |
| Aug 18, 5:25 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 50 min |
| Aug 18, 5:28 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 47 min |
| Aug 18, 6:15 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 37 min |
| Aug 18, 6:48 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 72 min |
| Aug 18, 7:54 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 36 min |
| Aug 18, 8:35 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 55 min |
| Aug 19, 4:19 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 41 min |
| Aug 19, 5:15 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 45 min |
| Aug 21, 2:53 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 37 min |
| Aug 21, 3:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 32 min |
| Aug 21, 3:28 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 62 min |
| Aug 21, 3:48 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 57 min |
| Aug 21, 4:13 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 77 min |
| Aug 21, 6:33 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 42 min |
| Aug 21, 7:07 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 53 min |
| Aug 21, 7:47 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Howard, City of Baltimore | 33 min |
| Aug 21, 9:44 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 16 min |
| Aug 24, 4:46 AM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 58 min |
| Aug 28, 12:13 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 47 min |
| Aug 29, 9:47 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 58 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Montgomery County27
- Baltimore County24
- Queen Anne's County24
- Prince George's County22
- Cecil County22
- Charles County22
- Frederick County21
- Saint Mary's County21
- Harford County20
- Howard County19
- Anne Arundel County19
- Kent County19
- Wicomico County18
- Carroll County17
- Caroline County16
- Talbot County16
- Washington County13
- Worcester County13
- Dorchester County13
- City of Baltimore12
- Calvert County11
- Allegany County10
- Somerset County10
- Garrett County9
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20082010
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.