Alert archive / Maryland / Frederick County
Weather alerts in Frederick County, Maryland, 2008
154 weather alerts in 2008, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Frederick County and its neighbors
Each county as a circle sized by its count in 2008. Tap one for its archive.
- Alerts
- 154
- Warnings
- 56
- Watches
- 35
- Advisories
- 35
- Busiest month
- June39 alerts
- Busiest day
- June 4, 20087 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Frederick County, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 37 | 23 | 38% | 20 | 75% | 31 min |
| Flash flood warnings | 1 | 0 | 100% | 0 |
Each office's whole area, 2008
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 36 | 8 | 78% | 21 | 43% | 18 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 391 | 220 | 44% | 579 | 76% | 21 min |
| NWS Baltimore/Washington: flash flood warnings | 23 | 11 | 52% | 53 | 75% | 117 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 9, 2:49 AM EST | Wind Advisory | LWX | 7 hr |
| Jan 16, 2:35 PM EST | Winter Weather Advisory | LWX | 36 hr |
| Jan 16, 9:28 PM EST | Winter Storm Warning | LWX | 24 hr |
| Jan 17, 12:53 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 21, 3:04 PM EST | Winter Weather Advisory | LWX | 22 hr |
| Jan 29, 7:26 AM EST | Freezing Rain Advisory | LWX | 3 hr |
| Jan 29, 3:18 PM EST | Wind Advisory | LWX | 20 hr |
| Jan 30, 2:58 PM EST | Winter Storm Watch | LWX | 24 hr |
| Jan 31, 3:03 PM EST | Winter Storm Warning | LWX | 21 hr |
| Jan 31, 3:03 PM EST | Winter Weather Advisory | LWX | 21 hr |
| Feb 1, 7:36 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 4, 11:49 PM EST | Dense Fog Advisory | LWX | 10 hr |
| Feb 6, 9:41 PM EST | Mesoscale Discussion | SPC | 64 min |
| Feb 9, 2:30 PM EST | High Wind Warning | LWX | 29 hr |
| Feb 9, 2:30 PM EST | Wind Advisory | LWX | 32 hr |
| Feb 11, 8:58 PM EST | Winter Weather Advisory | LWX | 40 hr |
| Feb 12, 4:15 PM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 12, 6:43 PM EST | Ice Storm Warning | LWX | 18 hr |
| Feb 13, 1:31 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 19, 9:51 PM EST | Snow Advisory | LWX | 24 hr |
| Feb 20, 10:07 PM EST | Winter Storm Watch | LWX | 17 hr |
| Feb 21, 2:38 PM EST | Winter Storm Warning | LWX | 22 hr |
| Feb 21, 2:38 PM EST | Winter Weather Advisory | LWX | 42 hr |
| Feb 22, 12:40 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 22, 7:01 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Mar 3, 3:44 PM EST | Flood Watch | LWX | 36 hr |
| Mar 4, 5:53 PM EST | Tornado Watch | SPC | 9 hr |
| Mar 5, 12:43 AM EST | Severe Thunderstorm Warning | LWX | 47 min |
| Mar 5, 2:48 AM EST | River Flood Warning | LWX | 19 hr |
| Mar 5, 10:50 AM EST | River Flood Warning | LWX | 11 hr |
| Mar 7, 3:42 PM EST | Wind Advisory | LWX | 35 hr |
| Mar 8, 3:06 AM EST | High Wind Warning | LWX | 19 hr |
| Mar 8, 3:22 PM EST | Severe Thunderstorm Warning | LWX | 53 min |
| Mar 8, 3:36 PM EST | Severe Thunderstorm Warning | LWX | 39 min |
| Mar 19, 8:46 PM EDT | Wind Advisory | LWX | 19 hr |
| Apr 15, 2:04 PM EDT | Freeze Warning | LWX | 18 hr |
| Apr 16, 9:41 PM EDT | Frost Advisory | LWX | 10 hr |
| Apr 20, 3:12 AM EDT | Flood Watch | LWX | 27 hr |
| Apr 20, 3:07 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Apr 20, 9:06 PM EDT | Areal Flood Warning | LWX | 6 hr |
| Apr 26, 6:11 AM EDT | Dense Fog Advisory | LWX | 4 hr |
| Apr 29, 2:23 PM EDT | Frost Advisory | LWX | 18 hr |
| May 8, 3:19 PM EDT | Flood Watch | LWX | 17 hr |
| May 10, 3:49 PM EDT | Flood Watch | LWX | 46 hr |
| May 11, 8:50 PM EDT | Areal Flood Warning | LWX | 6 hr |
| May 11, 11:20 PM EDT | River Flood Warning | LWX | 43 hr |
| May 12, 2:41 AM EDT | Areal Flood Warning | LWX | 18 hr |
| May 12, 3:30 PM EDT | River Flood Warning | LWX | 37 hr |
| May 15, 4:06 AM EDT | Flood Watch | LWX | 26 hr |
| May 31, 8:54 AM EDT | Mesoscale Discussion | SPC | 96 min |
| May 31, 10:14 AM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| May 31, 10:20 AM EDT | Tornado Watch | SPC | 7 hr |
| May 31, 10:25 AM EDT | Tornado Watch | SPC | 7 hr |
| Jun 4, 1:14 AM EDT | Flash Flood Watch | LWX | 8 hr |
| Jun 4, 11:51 AM EDT | Mesoscale Discussion | SPC | 84 min |
| Jun 4, 12:49 PM EDT | Tornado Watch | SPC | 7 hr |
| Jun 4, 2:44 PM EDT | Severe Thunderstorm Warning | LWX | 61 min |
| Jun 4, 2:45 PM EDT | Severe Thunderstorm Warning | LWX | 60 min |
| Jun 4, 2:55 PM EDT | Severe Thunderstorm Warning | LWX | 80 min |
| Jun 4, 7:36 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Jun 6, 4:17 AM EDT | Excessive Heat Watch | LWX | 48 hr |
| Jun 6, 3:19 PM EDT | Heat Advisory | LWX | 29 hr |
| Jun 7, 6:02 AM EDT | Dense Fog Advisory | LWX | 3 hr |
| Jun 7, 8:08 PM EDT | Heat Advisory | LWX | 71 hr |
| Jun 10, 2:27 PM EDT | Mesoscale Discussion | SPC | 63 min |
| Jun 10, 2:54 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 10, 4:15 PM EDT | Severe Thunderstorm Warning | LWX | 60 min |
| Jun 10, 5:17 PM EDT | Severe Thunderstorm Warning | LWX | 58 min |
| Jun 10, 7:15 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Jun 14, 12:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jun 16, 12:54 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 16, 1:21 PM EDT | Severe Thunderstorm Watch | SPC | 10 hr |
| Jun 16, 11:12 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Jun 22, 1:15 PM EDT | Severe Thunderstorm Watch | SPC | 11 hr |
| Jun 22, 4:28 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Jun 23, 4:38 PM EDT | Severe Thunderstorm Warning | LWX | 23 min |
| Jun 23, 5:00 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 23, 7:29 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Jun 23, 8:11 PM EDT | Severe Thunderstorm Warning | LWX | 54 min |
| Jun 23, 8:30 PM EDT | Mesoscale Discussion | SPC | 60 min |
| Jun 23, 8:46 PM EDT | Severe Thunderstorm Warning | LWX | 59 min |
| Jun 27, 11:37 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 27, 12:40 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 28, 6:31 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Jun 28, 7:12 PM EDT | Severe Thunderstorm Warning | LWX | 63 min |
| Jun 28, 7:31 PM EDT | Severe Thunderstorm Warning | LWX | 58 min |
| Jun 28, 8:11 PM EDT | Severe Thunderstorm Warning | LWX | 42 min |
| Jun 29, 2:04 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Jun 29, 4:37 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 29, 9:30 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 29, 10:30 PM EDT | Severe Thunderstorm Warning | LWX | 63 min |
| Jun 30, 7:52 PM EDT | Mesoscale Discussion | SPC | 113 min |
| Jul 4, 3:48 PM EDT | Mesoscale Discussion | SPC | 117 min |
| Jul 13, 1:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jul 20, 6:39 PM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Jul 20, 6:57 PM EDT | Severe Thunderstorm Warning | LWX | 37 min |
| Jul 20, 7:19 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| Jul 20, 7:53 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Jul 22, 9:46 AM EDT | Mesoscale Discussion | SPC | 59 min |
| Jul 23, 4:17 AM EDT | Flash Flood Watch | LWX | 18 hr |
| Jul 23, 3:25 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 26, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | 50 min |
| Jul 26, 6:28 PM EDT | Severe Thunderstorm Warning | LWX | 47 min |
| Jul 26, 7:33 PM EDT | Severe Thunderstorm Warning | LWX | 23 min |
| Jul 27, 11:03 AM EDT | Mesoscale Discussion | SPC | 57 min |
| Jul 27, 11:26 AM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jul 27, 4:02 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Jul 30, 4:53 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jul 30, 7:47 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Aug 2, 1:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Aug 2, 1:56 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 2, 3:09 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| Aug 2, 4:07 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Aug 2, 5:43 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Aug 7, 12:07 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Aug 7, 3:44 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Aug 10, 1:36 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 10, 3:21 PM EDT | Severe Thunderstorm Warning | LWX | 54 min |
| Aug 10, 4:06 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Aug 14, 3:18 PM EDT | Severe Thunderstorm Warning | LWX | 16 min |
| Aug 14, 4:00 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Aug 14, 4:27 PM EDT | Severe Thunderstorm Watch | SPC | 5 hr |
| Aug 14, 6:15 PM EDT | Mesoscale Discussion | SPC | 60 min |
| Sep 4, 5:26 PM EDT | Flash Flood Watch | LWX | 47 hr |
| Sep 5, 11:40 AM EDT | Inland Tropical Storm Warning | LWX | 6 hr |
| Sep 5, 5:56 PM EDT | Wind Advisory | LWX | 23 hr |
| Sep 6, 4:22 AM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 6, 1:58 PM EDT | Flash Flood Warning | LWX | 5 hr |
| Sep 9, 3:47 AM EDT | Flash Flood Watch | LWX | 11 hr |
| Sep 24, 11:47 AM EDT | High Wind Watch | LWX | 17 hr |
| Sep 30, 7:13 AM EDT | Dense Fog Advisory | LWX | 3 hr |
| Oct 1, 3:36 AM EDT | Dense Fog Advisory | LWX | 5 hr |
| Oct 18, 3:25 AM EDT | Freeze Watch | LWX | 24 hr |
| Oct 19, 3:39 AM EDT | Freeze Warning | LWX | 29 hr |
| Oct 20, 1:52 PM EDT | Fire Weather Watch | LWX | 20 hr |
| Oct 28, 4:24 AM EDT | Wind Advisory | LWX | 30 hr |
| Nov 13, 7:06 PM EST | Dense Fog Advisory | LWX | 15 hr |
| Nov 15, 12:22 PM EST | Tornado Watch | SPC | 7 hr |
| Nov 20, 11:34 AM EST | Winter Weather Advisory | LWX | 33 hr |
| Dec 7, 10:05 AM EST | Wind Advisory | LWX | 7 hr |
| Dec 10, 3:46 PM EST | Winter Weather Advisory | LWX | 42 hr |
| Dec 10, 9:56 PM EST | Flood Watch | LWX | 24 hr |
| Dec 12, 12:09 PM EST | River Flood Warning | LWX | 17 hr |
| Dec 15, 3:59 PM EST | Winter Storm Watch | LWX | 13 hr |
| Dec 16, 4:32 AM EST | Winter Weather Advisory | LWX | 30 hr |
| Dec 20, 12:00 AM EST | Dense Fog Advisory | LWX | 5 hr |
| Dec 20, 3:17 PM EST | Winter Weather Advisory | LWX | 18 hr |
| Dec 20, 11:55 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 21, 3:17 PM EST | Wind Chill Advisory | LWX | 21 hr |
| Dec 21, 3:21 PM EST | Wind Advisory | LWX | 21 hr |
| Dec 23, 3:40 PM EST | Winter Weather Advisory | LWX | 18 hr |
| Dec 27, 7:32 PM EST | Dense Fog Advisory | LWX | 8 hr |
| Dec 30, 2:58 PM EST | Wind Advisory | LWX | 31 hr |
| Dec 31, 4:22 AM EST | High Wind Warning | LWX | 12 hr |
By product
Every kind of product issued here, grouped by hazard. Each opens the same place narrowed to that product.
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20072009
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.