Alert archive / Maryland / Severe Thunderstorm Warnings
Severe Thunderstorm Warnings in Maryland, 2018
194 severe thunderstorm warnings in 2018. 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 2018. Tap one for its archive.
- Severe Thunderstorm Warnings
- 194
- Busiest month
- May57 severe thunderstorm warnings
- Busiest day
- May 13, 201812 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.
117 of 194 severe thunderstorm warnings covering Maryland in 2018 had a qualifying storm report inside them; 195 of 283 hail, wind and damage reports fell inside a warning, on average 20 minutes after it went out.
Maryland, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Severe thunderstorm warnings | 194 | 117 | 40% | 283 | 69% | 20 min |
Each office's whole area, 2018
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Pittsburgh, PA: severe thunderstorm warnings | 207 | 154 | 26% | 416 | 80% | 19 min |
| NWS Philadelphia/Mount Holly: severe thunderstorm warnings | 110 | 56 | 49% | 277 | 81% | 27 min |
| NWS Wakefield, VA: severe thunderstorm warnings | 122 | 85 | 30% | 212 | 77% | 22 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 312 | 208 | 33% | 690 | 70% | 20 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 |
|---|---|---|---|---|
| Jan 12, 5:49 PM EST | Severe Thunderstorm Warning | LWX | Washington | 56 min |
| Apr 16, 2:12 AM EDT | Severe Thunderstorm Warning | LWX | Charles | 17 min |
| Apr 16, 2:34 AM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Saint Mary's | 26 min |
| Apr 16, 2:41 AM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 16 min |
| Apr 16, 3:56 AM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's, Talbot | 24 min |
| May 10, 2:32 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 43 min |
| May 10, 3:53 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 37 min |
| May 10, 4:18 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 42 min |
| May 10, 5:17 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Howard, City of Baltimore | 43 min |
| May 10, 5:45 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 60 min |
| May 10, 6:37 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 23 min |
| May 10, 6:51 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 39 min |
| May 12, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford | 65 min |
| May 12, 7:16 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 44 min |
| May 12, 7:25 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's | 50 min |
| May 12, 7:44 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 46 min |
| May 12, 7:45 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 45 min |
| May 12, 7:46 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 22 min |
| May 12, 8:02 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 43 min |
| May 12, 8:11 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's | 49 min |
| May 12, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 62 min |
| May 12, 8:40 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 50 min |
| May 12, 8:47 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 88 min |
| May 12, 8:51 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's | 39 min |
| May 12, 9:16 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Wicomico | 59 min |
| May 12, 9:27 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 63 min |
| May 13, 12:46 AM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Worcester | 29 min |
| May 13, 6:05 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 55 min |
| May 13, 6:50 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 40 min |
| May 13, 7:22 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 25 min |
| May 13, 10:12 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 48 min |
| May 13, 10:21 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 39 min |
| May 13, 11:19 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester | 26 min |
| May 14, 4:12 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 48 min |
| May 14, 4:19 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 41 min |
| May 14, 4:51 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 39 min |
| May 14, 5:13 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 47 min |
| May 14, 5:29 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 61 min |
| May 14, 6:07 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 53 min |
| May 14, 6:33 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 57 min |
| May 14, 7:00 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Montgomery, Prince George's | 30 min |
| May 14, 7:12 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 63 min |
| May 14, 8:11 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico | 34 min |
| May 15, 6:07 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 38 min |
| May 15, 6:33 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 42 min |
| May 15, 6:35 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 40 min |
| May 15, 6:35 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent | 40 min |
| May 15, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford, Howard, Montgomery and 1 more | 65 min |
| May 15, 7:16 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford | 44 min |
| May 15, 7:18 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 42 min |
| May 15, 7:18 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 57 min |
| May 15, 7:54 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 51 min |
| May 15, 8:34 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 41 min |
| May 22, 3:25 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 50 min |
| May 22, 5:08 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 52 min |
| May 22, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 16 min |
| May 26, 3:25 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 22 min |
| May 26, 4:38 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 52 min |
| May 26, 5:25 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 28 min |
| May 27, 4:09 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, City of Baltimore | 51 min |
| May 27, 4:15 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 60 min |
| May 31, 4:10 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 50 min |
| Jun 1, 10:06 PM EDT | Severe Thunderstorm Warning | LWX | Frederick | 54 min |
| Jun 5, 6:50 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's | 40 min |
| Jun 5, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 35 min |
| Jun 5, 7:12 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 33 min |
| Jun 9, 1:21 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's | 39 min |
| Jun 9, 2:12 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 30 min |
| Jun 9, 2:24 PM EDT | Severe Thunderstorm Warning | PHI | Caroline | 51 min |
| Jun 9, 3:53 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 37 min |
| Jun 9, 5:46 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 44 min |
| Jun 9, 6:08 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 37 min |
| Jun 9, 6:34 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 45 min |
| Jun 10, 7:09 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 40 min |
| Jun 13, 10:33 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 27 min |
| Jun 18, 2:42 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 33 min |
| Jun 18, 4:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Howard | 19 min |
| Jun 18, 4:52 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 13 min |
| Jun 19, 2:16 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 29 min |
| Jun 20, 4:59 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 31 min |
| Jun 20, 6:08 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery, Washington | 30 min |
| Jun 23, 7:39 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 51 min |
| Jun 24, 2:32 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 43 min |
| Jun 24, 5:37 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 23 min |
| Jun 24, 5:49 PM EDT | Severe Thunderstorm Warning | AKQ | Somerset, Worcester | 41 min |
| Jun 24, 5:58 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford, Washington | 47 min |
| Jun 24, 8:30 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Kent, Queen Anne's, Talbot | 45 min |
| Jul 2, 5:31 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 44 min |
| Jul 3, 7:39 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 51 min |
| Jul 3, 7:52 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 38 min |
| Jul 3, 8:31 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 44 min |
| Jul 3, 8:41 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 49 min |
| Jul 3, 8:55 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 65 min |
| Jul 16, 5:35 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, Montgomery | 40 min |
| Jul 17, 2:55 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 34 min |
| Jul 17, 3:41 PM EDT | Severe Thunderstorm Warning | LWX | Prince George's | 34 min |
| Jul 17, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Saint Mary's | 25 min |
| Jul 17, 8:08 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 37 min |
| Jul 17, 8:42 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 33 min |
| Jul 22, 1:41 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent, Queen Anne's | 41 min |
| Jul 22, 1:45 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 30 min |
| Jul 22, 1:59 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 46 min |
| Jul 22, 2:17 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 43 min |
| Jul 22, 2:53 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, Howard, City of Baltimore | 29 min |
| Jul 22, 5:01 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's | 29 min |
| Jul 23, 7:59 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 17 min |
| Jul 27, 2:42 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 23 min |
| Jul 27, 3:09 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 31 min |
| Jul 27, 3:45 PM EDT | Severe Thunderstorm Warning | LWX | Saint Mary's | 30 min |
| Jul 27, 4:15 PM EDT | Severe Thunderstorm Warning | AKQ | Dorchester, Somerset, Wicomico | 45 min |
| Jul 27, 4:31 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 59 min |
| Jul 27, 4:52 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 38 min |
| Jul 27, 5:01 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 44 min |
| Jul 27, 5:17 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard, City of Baltimore | 28 min |
| Jul 27, 5:25 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll | 20 min |
| Jul 27, 5:38 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford, City of Baltimore | 47 min |
| Jul 27, 6:03 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 42 min |
| Aug 1, 10:19 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 56 min |
| Aug 1, 10:58 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 47 min |
| Aug 1, 11:05 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Montgomery | 25 min |
| Aug 1, 11:35 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 20 min |
| Aug 2, 1:55 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 50 min |
| Aug 2, 3:03 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Charles, Prince George's | 42 min |
| Aug 2, 3:25 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Prince George's | 35 min |
| Aug 3, 9:09 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard, Montgomery | 36 min |
| Aug 6, 12:40 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 36 min |
| Aug 6, 1:01 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 25 min |
| Aug 7, 3:55 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 30 min |
| Aug 7, 4:06 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 39 min |
| Aug 7, 6:13 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 47 min |
| Aug 7, 6:53 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Prince George's | 37 min |
| Aug 7, 7:14 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Prince George's | 46 min |
| Aug 8, 8:05 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 40 min |
| Aug 8, 8:28 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 47 min |
| Aug 8, 9:38 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick | 52 min |
| Aug 8, 10:00 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Howard | 45 min |
| Aug 8, 10:21 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 39 min |
| Aug 8, 10:46 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 32 min |
| Aug 11, 4:19 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 29 min |
| Aug 11, 6:08 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Queen Anne's | 52 min |
| Aug 11, 6:55 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Queen Anne's, Talbot | 50 min |
| Aug 12, 4:27 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 48 min |
| Aug 12, 5:09 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Charles, Prince George's, Saint Mary's | 47 min |
| Aug 13, 4:22 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 38 min |
| Aug 13, 4:57 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery, Prince George's | 48 min |
| Aug 13, 5:22 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard | 38 min |
| Aug 13, 5:49 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, City of Baltimore | 41 min |
| Aug 13, 6:20 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 55 min |
| Aug 13, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 50 min |
| Aug 17, 3:24 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 51 min |
| Aug 17, 3:40 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 65 min |
| Aug 18, 2:22 AM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 23 min |
| Aug 21, 2:33 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 27 min |
| Aug 21, 2:34 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 41 min |
| Aug 21, 3:00 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 45 min |
| Aug 21, 3:13 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 47 min |
| Aug 21, 3:43 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 47 min |
| Aug 21, 3:59 PM EDT | Severe Thunderstorm Warning | LWX | Allegany, Washington | 34 min |
| Aug 21, 5:12 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 48 min |
| Aug 21, 5:52 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 38 min |
| Aug 21, 6:09 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 51 min |
| Aug 21, 6:59 PM EDT | Severe Thunderstorm Warning | LWX | Frederick, Washington | 46 min |
| Aug 21, 8:25 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 50 min |
| Aug 31, 8:51 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel | 39 min |
| Sep 4, 3:49 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 26 min |
| Sep 4, 4:11 PM EDT | Severe Thunderstorm Warning | LWX | Charles | 49 min |
| Sep 6, 4:15 PM EDT | Severe Thunderstorm Warning | LWX | Allegany | 30 min |
| Sep 6, 7:08 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 36 min |
| Sep 6, 7:42 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore | 48 min |
| Sep 7, 4:48 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick | 42 min |
| Sep 7, 4:53 PM EDT | Severe Thunderstorm Warning | LWX | Calvert, Prince George's | 34 min |
| Sep 7, 5:34 PM EDT | Severe Thunderstorm Warning | LWX | Washington | 41 min |
| Sep 7, 6:39 PM EDT | Severe Thunderstorm Warning | LWX | Howard | 36 min |
| Sep 26, 4:32 PM EDT | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Washington | 58 min |
| Sep 26, 5:03 PM EDT | Severe Thunderstorm Warning | LWX | Frederick | 42 min |
| Sep 26, 6:04 PM EDT | Severe Thunderstorm Warning | LWX | Montgomery | 41 min |
| Sep 26, 6:41 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, City of Baltimore | 49 min |
| Sep 26, 6:50 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Howard | 55 min |
| Sep 26, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Harford | 52 min |
| Sep 26, 7:06 PM EDT | Severe Thunderstorm Warning | PHI | Cecil, Kent | 54 min |
| Sep 26, 7:16 PM EDT | Severe Thunderstorm Warning | PHI | Caroline, Cecil, Kent, Queen Anne's, Talbot | 43 min |
| Sep 26, 7:53 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 52 min |
| Oct 2, 7:36 PM EDT | Severe Thunderstorm Warning | PBZ | Garrett | 24 min |
| Oct 4, 7:03 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Howard, Montgomery, Prince George's | 42 min |
| Nov 2, 8:26 PM EDT | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Frederick, Harford | 49 min |
| Nov 2, 9:44 PM EDT | Severe Thunderstorm Warning | LWX | Anne Arundel, Baltimore, Harford, City of Baltimore | 31 min |
| Nov 2, 10:03 PM EDT | Severe Thunderstorm Warning | LWX | Harford | 27 min |
| Nov 2, 10:06 PM EDT | Severe Thunderstorm Warning | LWX | Charles, Saint Mary's | 39 min |
| Nov 2, 10:09 PM EDT | Severe Thunderstorm Warning | PHI | Cecil | 51 min |
| Nov 6, 11:52 AM EST | Severe Thunderstorm Warning | LWX | Anne Arundel, Calvert, Charles, Prince George's, Saint Mary's | 38 min |
| Dec 21, 3:51 PM EST | Severe Thunderstorm Warning | LWX | Howard, Montgomery | 24 min |
| Dec 21, 4:29 PM EST | Severe Thunderstorm Warning | LWX | Montgomery | 46 min |
| Dec 21, 4:45 PM EST | Severe Thunderstorm Warning | LWX | Baltimore, Carroll, Harford | 45 min |
| Dec 21, 5:01 PM EST | Severe Thunderstorm Warning | LWX | Carroll, Frederick, Howard | 29 min |
By county
Every county with at least one alert. A county page lists each alert that covered it.
- Washington County36
- Frederick County36
- Prince George's County34
- Baltimore County31
- Harford County26
- Charles County25
- Montgomery County25
- Carroll County24
- Anne Arundel County23
- Cecil County18
- Allegany County17
- Howard County16
- Queen Anne's County15
- Calvert County14
- Saint Mary's County13
- Kent County13
- City of Baltimore11
- Caroline County11
- Talbot County6
- Dorchester County4
- Somerset County4
- Garrett County3
- Wicomico County3
- Worcester County2
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordThe radar archive20172019
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.