Alert archive / Maryland / Washington County
Weather alerts in Washington County, Maryland, 2020
136 weather alerts in 2020, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Washington County and its neighbors
Each county as a circle sized by its count in 2020. Tap one for its archive.
- Alerts
- 136
- Warnings
- 49
- Watches
- 26
- Advisories
- 34
- Busiest month
- August24 alerts
- Busiest day
- April 13, 20206 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Washington County, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 38 | 31 | 18% | 20 | 100% | 22 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2020
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 27 | 6 | 78% | 15 | 47% | 9 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 456 | 314 | 31% | 1,047 | 79% | 23 min |
| NWS Baltimore/Washington: flash flood warnings | 66 | 34 | 48% | 130 | 90% | 72 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 4, 4:14 AM EST | Dense Fog Advisory | LWX | 7 hr |
| Jan 6, 1:49 PM EST | Winter Weather Advisory | LWX | 29 hr |
| Jan 7, 12:29 PM EST | Mesoscale Discussion | SPC | 2 hr |
| Jan 8, 3:40 AM EST | Wind Advisory | LWX | 13 hr |
| Jan 11, 1:13 PM EST | Wind Advisory | LWX | 20 hr |
| Jan 14, 10:41 PM EST | Dense Fog Advisory | LWX | 10 hr |
| Jan 15, 9:26 AM EST | Dense Fog Advisory | LWX | 34 min |
| Jan 15, 2:50 PM EST | Wind Advisory | LWX | 22 hr |
| Jan 17, 1:33 PM EST | Winter Weather Advisory | LWX | 29 hr |
| Feb 6, 9:30 PM EST | Wind Advisory | LWX | 20 hr |
| Feb 7, 4:08 AM EST | Dense Fog Advisory | LWX | 3 hr |
| Feb 7, 11:22 PM EST | Special Weather Statement | LWX | 38 min |
| Feb 26, 12:54 AM EST | Dense Fog Advisory | LWX | 8 hr |
| Feb 26, 2:49 PM EST | Mesoscale Discussion | SPC | 116 min |
| Mar 3, 4:27 PM EST | Mesoscale Discussion | SPC | 2 hr |
| Mar 3, 10:03 PM EST | Severe Thunderstorm Warning | LWX | 27 min |
| Mar 3, 10:26 PM EST | Severe Thunderstorm Warning | LWX | 34 min |
| Mar 3, 10:52 PM EST | Mesoscale Discussion | SPC | 113 min |
| Mar 3, 10:54 PM EST | Severe Thunderstorm Warning | LWX | 36 min |
| Mar 29, 3:32 AM EDT | Dense Fog Advisory | LWX | 7 hr |
| Mar 29, 11:16 PM EDT | Dense Fog Advisory | LWX | 5 hr |
| Apr 8, 2:14 AM EDT | Severe Thunderstorm Watch | SPC | 2 hr |
| Apr 8, 2:50 AM EDT | Severe Thunderstorm Warning | LWX | 55 min |
| Apr 8, 3:43 AM EDT | Severe Thunderstorm Warning | LWX | 47 min |
| Apr 8, 8:13 PM EDT | Wind Advisory | LWX | 23 hr |
| Apr 9, 11:44 AM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Apr 9, 7:38 PM EDT | Wind Advisory | LWX | 22 hr |
| Apr 9, 7:47 PM EDT | Freeze Watch | LWX | 19 hr |
| Apr 10, 2:28 PM EDT | Freeze Warning | LWX | 19 hr |
| Apr 12, 12:35 PM EDT | Wind Advisory | LWX | 29 hr |
| Apr 13, 10:34 AM EDT | Mesoscale Discussion | SPC | 86 min |
| Apr 13, 11:33 AM EDT | Tornado Watch | SPC | 5 hr |
| Apr 13, 11:54 AM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Apr 13, 12:42 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Apr 13, 1:20 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Apr 13, 1:20 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Apr 15, 1:09 PM EDT | Freeze Watch | LWX | 24 hr |
| Apr 16, 1:19 PM EDT | Freeze Warning | LWX | 20 hr |
| Apr 17, 7:20 PM EDT | Freeze Watch | LWX | 18 hr |
| Apr 18, 1:19 PM EDT | Frost Advisory | LWX | 20 hr |
| Apr 18, 9:22 PM EDT | Freeze Warning | LWX | 12 hr |
| Apr 21, 4:04 AM EDT | Freeze Warning | LWX | 27 hr |
| Apr 29, 4:24 AM EDT | Flood Watch | LWX | 39 hr |
| Apr 30, 10:56 AM EDT | River Flood Watch | LWX | 17 hr |
| May 1, 4:18 AM EDT | River Flood Warning | LWX | 23 hr |
| May 7, 4:29 AM EDT | Freeze Watch | LWX | 10 hr |
| May 7, 2:16 PM EDT | Freeze Warning | LWX | 43 hr |
| May 8, 3:30 AM EDT | Freeze Watch | LWX | 24 hr |
| May 9, 3:36 AM EDT | Freeze Warning | LWX | 28 hr |
| May 11, 3:43 AM EDT | Frost Advisory | LWX | 26 hr |
| May 12, 2:41 PM EDT | Frost Advisory | LWX | 18 hr |
| May 23, 4:09 AM EDT | Dense Fog Advisory | LWX | 4 hr |
| May 29, 12:27 PM EDT | Mesoscale Discussion | SPC | 63 min |
| May 29, 2:25 PM EDT | Severe Thunderstorm Warning | LWX | 29 min |
| May 29, 2:25 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 29, 2:40 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| May 29, 2:53 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Jun 3, 3:10 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 4, 2:02 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Jun 4, 2:29 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 4, 4:41 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jun 4, 5:05 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jun 4, 5:20 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jun 4, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | 35 min |
| Jun 5, 3:40 AM EDT | Flash Flood Watch | LWX | 17 hr |
| Jun 5, 2:20 PM EDT | Severe Thunderstorm Warning | LWX | 27 min |
| Jun 5, 3:18 PM EDT | Areal Flood Warning | LWX | 116 min |
| Jun 10, 3:12 PM EDT | Severe Thunderstorm Warning | LWX | 21 min |
| Jun 22, 1:58 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 22, 3:27 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Jun 22, 5:58 PM EDT | Severe Thunderstorm Warning | LWX | 47 min |
| Jun 23, 1:58 PM EDT | Flash Flood Watch | LWX | 10 hr |
| Jun 23, 5:26 PM EDT | Severe Thunderstorm Warning | LWX | 49 min |
| Jun 25, 1:48 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jun 25, 4:12 PM EDT | Severe Thunderstorm Warning | LWX | 16 min |
| Jul 6, 6:50 PM EDT | Severe Thunderstorm Warning | LWX | 10 min |
| Jul 18, 2:59 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 19, 2:47 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 21, 2:01 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jul 21, 4:26 PM EDT | Severe Thunderstorm Warning | LWX | 37 min |
| Jul 22, 12:07 AM EDT | Heat Advisory | LWX | 18 hr |
| Jul 22, 10:48 AM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 22, 12:01 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 24, 9:32 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Jul 30, 10:01 PM EDT | Flash Flood Watch | LWX | 20 hr |
| Aug 1, 4:00 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 1, 7:05 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 1, 7:40 PM EDT | Severe Thunderstorm Warning | LWX | 50 min |
| Aug 1, 8:29 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Aug 1, 9:07 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Aug 1, 9:40 PM EDT | Areal Flood Warning | LWX | 6 hr |
| Aug 1, 9:54 PM EDT | Severe Thunderstorm Warning | LWX | 31 min |
| Aug 2, 3:28 PM EDT | Flash Flood Watch | LWX | 45 hr |
| Aug 5, 10:51 PM EDT | Flash Flood Watch | LWX | 25 hr |
| Aug 7, 1:30 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 7, 2:08 PM EDT | Severe Thunderstorm Warning | LWX | 52 min |
| Aug 11, 3:19 PM EDT | Flash Flood Watch | LWX | 52 hr |
| Aug 23, 3:57 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 24, 12:44 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 24, 2:38 PM EDT | Severe Thunderstorm Warning | LWX | 20 min |
| Aug 25, 3:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Aug 25, 3:34 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 25, 4:12 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Aug 25, 4:50 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Aug 27, 2:14 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 27, 6:35 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Aug 28, 9:55 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 28, 1:37 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 28, 3:02 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Sep 2, 6:17 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Sep 2, 6:32 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Sep 3, 3:06 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Sep 3, 3:30 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Sep 3, 3:42 PM EDT | Tornado Watch | SPC | 6 hr |
| Sep 19, 1:37 PM EDT | Frost Advisory | LWX | 20 hr |
| Sep 20, 1:43 PM EDT | Frost Advisory | LWX | 19 hr |
| Sep 21, 1:31 PM EDT | Frost Advisory | LWX | 19 hr |
| Oct 16, 2:39 PM EDT | Frost Advisory | LWX | 19 hr |
| Oct 17, 2:25 PM EDT | Frost Advisory | LWX | 20 hr |
| Oct 22, 1:01 AM EDT | Dense Fog Advisory | LWX | 9 hr |
| Oct 22, 10:21 AM EDT | Dense Fog Advisory | LWX | 99 min |
| Oct 31, 6:59 PM EDT | Wind Advisory | LWX | 44 hr |
| Nov 1, 8:45 PM EST | Wind Advisory | LWX | 3 hr |
| Nov 14, 2:06 PM EST | Wind Advisory | LWX | 41 hr |
| Nov 15, 4:56 PM EST | Severe Thunderstorm Warning | LWX | 64 min |
| Nov 15, 4:58 PM EST | Severe Thunderstorm Warning | LWX | 47 min |
| Dec 13, 2:25 PM EST | Winter Weather Advisory | LWX | 23 hr |
| Dec 14, 4:43 AM EST | Winter Storm Watch | LWX | 35 hr |
| Dec 15, 4:09 AM EST | Winter Storm Warning | LWX | 46 hr |
| Dec 16, 8:38 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Dec 16, 1:57 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 23, 4:27 AM EST | Flash Flood Watch | LWX | 47 hr |
| Dec 23, 9:07 PM EST | River Flood Watch | LWX | 60 hr |
| Dec 24, 4:41 AM EST | River Flood Watch | LWX | 38 hr |
| Dec 24, 7:21 PM EST | River Flood Warning | LWX | 35 hr |
| Dec 24, 8:05 PM EST | River Flood Watch | LWX | 15 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 | 38 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 26 |
| Special Weather Statement | 1 |
| Flooding | |
| Areal Flood Warning | 2 |
| River Flood Warning | 2 |
| Flash Flood Watch | 7 |
| Flood Watch | 1 |
| River Flood Watch | 4 |
| Winter | |
| Winter Storm Warning | 1 |
| Winter Storm Watch | 1 |
| Winter Weather Advisory | 3 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 6 |
| Freeze Watch | 5 |
| Frost Advisory | 8 |
| Wind and dust | |
| Wind Advisory | 10 |
| Fog and smoke | |
| Dense Fog Advisory | 10 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20192021
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.