Alert archive / Maryland / Saint Mary's County
Weather alerts in Saint Mary's County, Maryland, 2021
171 weather alerts in 2021, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Saint Mary's County and its neighbors
Each county as a circle sized by its count in 2021. Tap one for its archive.
- Alerts
- 171
- Warnings
- 58
- Watches
- 34
- Advisories
- 50
- Busiest month
- June25 alerts
- Busiest day
- June 4, 20218 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
1 of 4 tornado warnings covering Saint Mary's County in 2021 had a tornado report inside them.
Saint Mary's County, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 4 | 1 | 75% | 0 | ||
| Severe thunderstorm warnings | 34 | 21 | 38% | 52 | 92% | 23 min |
| Flash flood warnings | 2 | 1 | 50% | 2 | 100% | 21 min |
Each office's whole area, 2021
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 49 | 10 | 80% | 13 | 100% | 11 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 544 | 396 | 27% | 1,446 | 83% | 20 min |
| NWS Baltimore/Washington: flash flood warnings | 76 | 32 | 58% | 96 | 77% | 60 min |
An office's figures cover every county it serves, including across state lines.
Verified by the Iowa Environmental Mesonet's Cow, which matches each storm-based warning with the local storm reports inside its polygon while it was in force, within 15 km of its edge: a tornado warning counts as verified on a tornado report, a severe thunderstorm warning on hail of 1 inch or more, a gust of 58 mph or more, or wind damage, a flash flood warning on a flash flood report. The false alarm ratio is the share of warnings with no such report; "inside a warning" is the probability of detection, the share of reports that fell inside one; lead time runs from the warning's issue to each report inside it, counting zero for a report that came first. A warning with no report is not proof nothing happened: reports come from spotters, the public and damage surveys, and are thin where few people live.
The alerts
Every alert, in the order issued. Times are local, Eastern Time. Each opens its own page with the text, the map, the radar and the sounding.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jan 5, 2:11 PM EST | Coastal Flood Advisory | LWX | 7 hr |
| Jan 29, 3:10 PM EST | Winter Storm Watch | LWX | 23 hr |
| Jan 30, 9:02 AM EST | Winter Storm Warning | LWX | 69 hr |
| Jan 31, 6:50 PM EST | Winter Weather Advisory | LWX | 42 hr |
| Feb 1, 4:37 AM EST | Coastal Flood Advisory | LWX | 83 min |
| Feb 5, 3:13 PM EST | Winter Storm Watch | LWX | 12 hr |
| Feb 6, 3:22 AM EST | Winter Weather Advisory | LWX | 33 hr |
| Feb 10, 3:33 AM EST | Winter Storm Watch | LWX | 24 hr |
| Feb 11, 3:28 AM EST | Winter Weather Advisory | LWX | 30 hr |
| Feb 11, 6:08 PM EST | Winter Storm Watch | LWX | 21 hr |
| Feb 12, 3:10 PM EST | Ice Storm Warning | LWX | 30 hr |
| Feb 12, 3:10 PM EST | Winter Weather Advisory | LWX | 43 hr |
| Feb 13, 10:02 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 16, 4:56 AM EST | Winter Storm Watch | LWX | 29 hr |
| Feb 17, 3:24 AM EST | Winter Storm Warning | LWX | 57 hr |
| Feb 17, 9:56 AM EST | Winter Weather Advisory | LWX | 27 hr |
| Feb 18, 10:23 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Feb 19, 4:56 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Feb 28, 9:09 PM EST | Dense Fog Advisory | LWX | 8 hr |
| Mar 10, 3:43 PM EST | Fire Weather Watch | LWX | 12 hr |
| Mar 11, 3:28 AM EST | Red Flag Warning | LWX | 15 hr |
| Mar 14, 4:01 AM EDT | Red Flag Warning | LWX | 18 hr |
| Mar 18, 2:32 PM EDT | Wind Advisory | LWX | 20 hr |
| Mar 20, 3:12 AM EDT | Coastal Flood Advisory | LWX | 12 hr |
| Mar 24, 5:41 PM EDT | Areal Flood Warning | LWX | 9 hr |
| Mar 24, 9:09 PM EDT | Dense Fog Advisory | LWX | 14 hr |
| Mar 28, 1:24 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 28, 5:05 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Mar 28, 7:05 PM EDT | Severe Thunderstorm Warning | LWX | 55 min |
| Apr 12, 9:38 PM EDT | Coastal Flood Advisory | LWX | 14 hr |
| Apr 13, 9:05 PM EDT | Coastal Flood Advisory | LWX | 15 hr |
| Apr 21, 12:22 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Apr 21, 12:28 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Apr 21, 12:43 PM EDT | Severe Thunderstorm Warning | LWX | 33 min |
| Apr 21, 1:09 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Apr 21, 2:47 PM EDT | Wind Advisory | LWX | 5 hr |
| Apr 22, 12:03 PM EDT | Frost Advisory | LWX | 20 hr |
| Apr 29, 8:18 PM EDT | Wind Advisory | LWX | 30 hr |
| Apr 30, 5:11 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| May 4, 1:51 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 4, 3:50 PM EDT | Mesoscale Discussion | SPC | 115 min |
| May 4, 5:49 PM EDT | Severe Thunderstorm Warning | LWX | 56 min |
| May 5, 1:03 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 5, 3:17 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| May 26, 1:21 PM EDT | Mesoscale Discussion | SPC | 84 min |
| May 26, 2:48 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 26, 9:35 PM EDT | Severe Thunderstorm Warning | LWX | 27 min |
| May 28, 2:34 PM EDT | Tornado Warning | LWX | 26 min |
| May 28, 3:56 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 28, 7:18 PM EDT | Mesoscale Discussion | SPC | 87 min |
| May 29, 4:40 PM EDT | Coastal Flood Advisory | LWX | 119 min |
| May 30, 3:02 AM EDT | Coastal Flood Advisory | LWX | 11 hr |
| Jun 3, 1:46 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Jun 3, 2:48 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 3, 4:47 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jun 4, 12:46 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jun 4, 12:59 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 4, 1:36 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Jun 4, 2:17 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Jun 4, 2:50 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jun 4, 3:19 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| Jun 4, 3:54 PM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Jun 4, 4:12 PM EDT | Mesoscale Discussion | SPC | 93 min |
| Jun 9, 5:14 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Jun 9, 6:09 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 9, 6:55 PM EDT | Areal Flood Warning | LWX | 2 hr |
| Jun 9, 7:35 PM EDT | Flash Flood Warning | LWX | 95 min |
| Jun 9, 9:10 PM EDT | Areal Flood Warning | LWX | 4 hr |
| Jun 10, 2:53 AM EDT | Flash Flood Watch | LWX | 43 hr |
| Jun 10, 5:10 AM EDT | Areal Flood Warning | LWX | 47 min |
| Jun 11, 2:47 PM EDT | Coastal Flood Advisory | LWX | 22 hr |
| Jun 11, 10:34 PM EDT | Coastal Flood Advisory | LWX | 22 hr |
| Jun 12, 8:43 PM EDT | Coastal Flood Advisory | LWX | 15 hr |
| Jun 14, 6:41 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 14, 7:29 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 14, 10:09 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 2:23 PM EDT | Flash Flood Watch | LWX | 42 hr |
| Jul 1, 11:45 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 1, 12:46 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 1, 2:36 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jul 7, 11:15 AM EDT | Tropical Storm Watch | LWX | 12 hr |
| Jul 7, 3:12 PM EDT | Flash Flood Watch | LWX | 33 hr |
| Jul 7, 11:05 PM EDT | Tropical Storm Warning | LWX | 27 hr |
| Jul 8, 1:50 PM EDT | Tornado Watch | SPC | 11 hr |
| Jul 8, 10:31 PM EDT | Tornado Warning | LWX | 29 min |
| Jul 8, 11:13 PM EDT | Flash Flood Warning | LWX | 76 min |
| Jul 8, 11:13 PM EDT | Tornado Warning | LWX | 17 min |
| Jul 9, 12:40 AM EDT | Coastal Flood Warning | LWX | 2 hr |
| Jul 9, 2:15 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 9, 6:19 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| Jul 14, 5:24 PM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Jul 14, 5:46 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jul 14, 6:03 PM EDT | Severe Thunderstorm Warning | LWX | 57 min |
| Jul 16, 2:57 PM EDT | Heat Advisory | LWX | 28 hr |
| Jul 17, 1:13 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jul 21, 11:56 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 21, 3:46 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jul 21, 5:05 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jul 26, 8:46 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jul 28, 4:37 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Jul 28, 5:05 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jul 29, 3:00 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 10, 1:33 PM EDT | Excessive Heat Watch | LWX | 37 hr |
| Aug 10, 1:33 PM EDT | Heat Advisory | LWX | 29 hr |
| Aug 10, 2:30 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 10, 7:28 PM EDT | Severe Thunderstorm Warning | LWX | 62 min |
| Aug 11, 2:02 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 11, 3:47 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Aug 12, 2:15 AM EDT | Heat Advisory | LWX | 18 hr |
| Aug 12, 6:04 PM EDT | Heat Advisory | LWX | 25 hr |
| Aug 13, 1:11 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 13, 7:07 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Aug 13, 7:11 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Aug 13, 7:41 PM EDT | Severe Thunderstorm Warning | LWX | 21 min |
| Aug 14, 1:10 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 14, 11:54 PM EDT | Areal Flood Warning | LWX | 4 hr |
| Aug 18, 10:58 AM EDT | Mesoscale Discussion | SPC | 92 min |
| Aug 18, 11:37 AM EDT | Tornado Watch | SPC | 11 hr |
| Aug 18, 4:29 PM EDT | Severe Thunderstorm Warning | LWX | 14 min |
| Aug 19, 2:11 PM EDT | Flash Flood Watch | LWX | 28 hr |
| Aug 22, 1:14 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Aug 22, 1:51 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Aug 22, 2:14 PM EDT | Areal Flood Warning | LWX | 2 hr |
| Aug 27, 6:28 PM EDT | Severe Thunderstorm Warning | LWX | 47 min |
| Aug 27, 10:08 PM EDT | Severe Thunderstorm Warning | LWX | 52 min |
| Aug 30, 4:54 AM EDT | Flash Flood Watch | LWX | 62 hr |
| Aug 30, 6:04 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Sep 1, 10:14 AM EDT | Coastal Flood Advisory | LWX | 19 hr |
| Sep 1, 11:03 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 1, 11:46 AM EDT | Tornado Watch | SPC | 9 hr |
| Sep 1, 1:31 PM EDT | Tornado Warning | LWX | 29 min |
| Sep 1, 1:32 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Sep 21, 3:11 AM EDT | Coastal Flood Advisory | LWX | 20 hr |
| Sep 22, 1:15 AM EDT | Coastal Flood Advisory | LWX | 4 hr |
| Sep 22, 3:14 AM EDT | Coastal Flood Advisory | LWX | 46 hr |
| Sep 22, 9:39 AM EDT | Coastal Flood Warning | LWX | 34 hr |
| Sep 22, 4:22 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Sep 22, 6:14 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 23, 3:13 AM EDT | Mesoscale Discussion | SPC | 5 hr |
| Oct 7, 1:39 PM EDT | Coastal Flood Advisory | LWX | 9 hr |
| Oct 8, 2:42 PM EDT | Coastal Flood Advisory | LWX | 2 hr |
| Oct 9, 10:36 AM EDT | Coastal Flood Advisory | LWX | 14 hr |
| Oct 9, 8:07 PM EDT | Coastal Flood Watch | LWX | 7 hr |
| Oct 9, 11:31 PM EDT | Coastal Flood Advisory | LWX | 8 hr |
| Oct 10, 3:00 AM EDT | Coastal Flood Warning | LWX | 18 hr |
| Oct 10, 2:29 PM EDT | Coastal Flood Advisory | LWX | 33 hr |
| Oct 10, 8:58 PM EDT | Coastal Flood Watch | LWX | 6 hr |
| Oct 11, 3:18 AM EDT | Coastal Flood Warning | LWX | 19 hr |
| Oct 11, 3:18 AM EDT | Coastal Flood Advisory | LWX | 48 hr |
| Oct 11, 2:53 PM EDT | Coastal Flood Watch | LWX | 24 hr |
| Oct 13, 3:38 AM EDT | Coastal Flood Advisory | LWX | 25 hr |
| Oct 14, 2:36 AM EDT | Dense Fog Advisory | LWX | 7 hr |
| Oct 15, 3:11 PM EDT | Coastal Flood Advisory | LWX | 30 hr |
| Oct 25, 6:26 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Oct 25, 8:13 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Oct 26, 2:55 AM EDT | Wind Advisory | LWX | 21 hr |
| Oct 27, 10:50 AM EDT | Coastal Flood Watch | LWX | 29 hr |
| Oct 28, 1:06 AM EDT | Coastal Flood Advisory | LWX | 15 hr |
| Oct 28, 4:29 AM EDT | Coastal Flood Warning | LWX | 72 hr |
| Oct 28, 2:24 PM EDT | High Wind Warning | LWX | 24 hr |
| Oct 28, 2:24 PM EDT | Wind Advisory | LWX | 26 hr |
| Oct 29, 3:36 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Oct 30, 4:22 AM EDT | Coastal Flood Advisory | LWX | 49 hr |
| Oct 31, 10:03 PM EDT | Coastal Flood Advisory | LWX | 3 hr |
| Nov 2, 3:22 AM EDT | Frost Advisory | LWX | 30 hr |
| Nov 3, 3:38 PM EDT | Frost Advisory | LWX | 17 hr |
| Nov 4, 4:06 AM EDT | Frost Advisory | LWX | 29 hr |
| Nov 6, 2:21 PM EDT | Coastal Flood Advisory | LWX | 4 hr |
| Nov 9, 5:46 PM EST | Coastal Flood Advisory | LWX | 74 min |
| Nov 26, 1:48 PM EST | Wind Advisory | LWX | 3 hr |
| Dec 10, 10:48 AM EST | Wind Advisory | LWX | 38 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 34 |
| Tornado Warning | 4 |
| Severe Thunderstorm Watch | 14 |
| Tornado Watch | 3 |
| Mesoscale Discussion | 29 |
| Flooding | |
| Areal Flood Warning | 6 |
| Flash Flood Warning | 2 |
| Flash Flood Watch | 5 |
| Winter | |
| Ice Storm Warning | 1 |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 5 |
| Winter Weather Advisory | 5 |
| Heat | |
| Excessive Heat Watch | 1 |
| Heat Advisory | 4 |
| Cold | |
| Frost Advisory | 4 |
| Wind and dust | |
| High Wind Warning | 1 |
| Wind Advisory | 7 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 3 |
| Tropical | |
| Tropical Storm Warning | 1 |
| Tropical Storm Watch | 1 |
| Coast and beach | |
| Coastal Flood Warning | 5 |
| Coastal Flood Watch | 4 |
| Coastal Flood Advisory | 27 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20202022
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.