Alert archive / Virginia / Fairfax County
Weather alerts in Fairfax County, Virginia, 2016
172 weather alerts in 2016, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Fairfax County and its neighbors
Each county as a circle sized by its count in 2016. Tap one for its archive.
- Alerts
- 172
- Warnings
- 62
- Watches
- 32
- Advisories
- 34
- Busiest month
- June35 alerts
- Busiest day
- June 21, 201613 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Fairfax County, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 42 | 34 | 19% | 37 | 78% | 17 min |
| Flash flood warnings | 3 | 3 | 0% | 3 | 100% | 95 min |
Each office's whole area, 2016
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 14 | 1 | 93% | 2 | 50% | 8 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 305 | 212 | 30% | 851 | 81% | 20 min |
| NWS Baltimore/Washington: flash flood warnings | 45 | 24 | 47% | 61 | 89% | 88 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 12, 3:31 AM EST | Wind Advisory | LWX | 20 hr |
| Jan 20, 10:13 AM EST | Blizzard Watch | LWX | 26 hr |
| Jan 20, 11:14 AM EST | Winter Weather Advisory | LWX | 14 hr |
| Jan 21, 12:09 PM EST | Blizzard Warning | LWX | 60 hr |
| Jan 22, 12:34 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 22, 4:42 PM EST | Mesoscale Discussion | SPC | 6 hr |
| Jan 22, 9:56 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 23, 4:20 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 23, 8:51 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 23, 6:40 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Feb 2, 10:39 AM EST | Flood Watch | LWX | 40 hr |
| Feb 3, 7:51 AM EST | River Flood Watch | LWX | 30 hr |
| Feb 3, 8:13 PM EST | Dense Fog Advisory | LWX | 10 hr |
| Feb 7, 8:22 PM EST | Winter Weather Advisory | LWX | 4 days |
| Feb 12, 11:37 AM EST | Winter Weather Advisory | LWX | 27 hr |
| Feb 12, 1:12 PM EST | Wind Chill Advisory | LWX | 43 hr |
| Feb 12, 1:13 PM EST | Wind Advisory | LWX | 23 hr |
| Feb 13, 3:06 PM EST | Winter Storm Watch | LWX | 23 hr |
| Feb 14, 3:44 AM EST | Winter Storm Warning | LWX | 56 hr |
| Feb 14, 2:13 PM EST | Winter Weather Advisory | LWX | 41 hr |
| Feb 15, 1:46 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 15, 3:06 PM EST | Flood Watch | LWX | 24 hr |
| Feb 21, 5:20 AM EST | Flash Flood Watch | LWX | 7 hr |
| Feb 23, 3:21 PM EST | Flood Watch | LWX | 33 hr |
| Feb 24, 2:04 AM EST | Coastal Flood Advisory | LWX | 35 hr |
| Feb 24, 1:18 PM EST | Mesoscale Discussion | SPC | 117 min |
| Feb 24, 3:06 PM EST | Mesoscale Discussion | SPC | 54 min |
| Feb 24, 3:20 PM EST | Tornado Watch | SPC | 8 hr |
| Feb 24, 4:46 PM EST | Mesoscale Discussion | SPC | 89 min |
| Feb 24, 4:51 PM EST | Severe Thunderstorm Warning | LWX | 39 min |
| Feb 24, 5:29 PM EST | Severe Thunderstorm Warning | LWX | 46 min |
| Feb 24, 5:46 PM EST | Severe Thunderstorm Warning | LWX | 59 min |
| Feb 24, 6:02 PM EST | Areal Flood Warning | LWX | 8 hr |
| Feb 24, 6:46 PM EST | Flash Flood Warning | LWX | 119 min |
| Mar 3, 3:31 AM EST | Winter Weather Advisory | LWX | 29 hr |
| Mar 23, 9:26 PM EDT | Fire Weather Watch | LWX | 7 hr |
| Mar 24, 3:58 AM EDT | Red Flag Warning | LWX | 16 hr |
| Mar 28, 3:57 AM EDT | Wind Advisory | LWX | 17 hr |
| Apr 1, 2:29 PM EDT | High Wind Watch | LWX | 14 hr |
| Apr 2, 4:10 AM EDT | Freeze Warning | LWX | 29 hr |
| Apr 2, 4:10 AM EDT | High Wind Warning | LWX | 28 hr |
| Apr 2, 4:10 AM EDT | Wind Advisory | LWX | 26 hr |
| Apr 2, 9:10 PM EDT | Special Weather Statement | LWX | 2 hr |
| Apr 3, 2:39 PM EDT | Freeze Watch | LWX | 25 hr |
| Apr 4, 4:04 AM EDT | Freeze Warning | LWX | 30 hr |
| Apr 4, 4:43 AM EDT | Freeze Watch | LWX | 23 hr |
| Apr 5, 4:09 AM EDT | Freeze Warning | LWX | 29 hr |
| Apr 7, 5:00 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Apr 8, 4:08 AM EDT | Freeze Watch | LWX | 23 hr |
| Apr 8, 9:27 PM EDT | Wind Advisory | LWX | 23 hr |
| Apr 9, 3:30 AM EDT | Freeze Warning | LWX | 31 hr |
| Apr 13, 1:26 PM EDT | Frost Advisory | LWX | 20 hr |
| Apr 14, 1:27 PM EDT | Frost Advisory | LWX | 20 hr |
| Apr 19, 3:17 AM EDT | Red Flag Warning | LWX | 17 hr |
| May 2, 5:42 AM EDT | Dense Fog Advisory | LWX | 2 hr |
| May 2, 2:17 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 2, 5:50 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| May 2, 6:15 PM EDT | Severe Thunderstorm Warning | LWX | 29 min |
| May 2, 6:27 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| May 2, 6:34 PM EDT | Mesoscale Discussion | SPC | 56 min |
| May 2, 7:24 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| May 2, 8:49 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| May 3, 3:48 PM EDT | Mesoscale Discussion | SPC | 117 min |
| May 14, 6:55 PM EDT | Severe Thunderstorm Warning | LWX | 50 min |
| Jun 3, 3:02 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 5, 1:14 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Jun 5, 3:12 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 16, 4:04 AM EDT | Flash Flood Watch | LWX | 23 hr |
| Jun 16, 11:27 AM EDT | Mesoscale Discussion | SPC | 63 min |
| Jun 16, 1:08 PM EDT | Mesoscale Discussion | SPC | 97 min |
| Jun 16, 1:58 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 16, 4:20 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Jun 16, 6:37 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Jun 16, 6:54 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jun 16, 7:15 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 16, 8:20 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jun 16, 9:21 PM EDT | Mesoscale Discussion | SPC | 54 min |
| Jun 21, 12:00 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 21, 1:06 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 21, 1:12 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Jun 21, 2:20 PM EDT | Severe Thunderstorm Warning | LWX | 36 min |
| Jun 21, 2:54 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jun 21, 3:27 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Jun 21, 3:34 PM EDT | Mesoscale Discussion | SPC | 86 min |
| Jun 21, 4:53 PM EDT | Severe Thunderstorm Warning | LWX | 52 min |
| Jun 21, 5:31 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jun 21, 5:32 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jun 21, 5:51 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jun 21, 6:30 PM EDT | Mesoscale Discussion | SPC | 90 min |
| Jun 21, 7:04 PM EDT | Severe Thunderstorm Warning | LWX | 14 min |
| Jun 24, 12:57 PM EDT | Mesoscale Discussion | SPC | 63 min |
| Jun 28, 2:40 AM EDT | Areal Flood Warning | LWX | 3 hr |
| Jun 28, 4:09 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 28, 4:46 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jun 28, 5:25 PM EDT | Severe Thunderstorm Warning | LWX | 50 min |
| Jun 28, 6:52 PM EDT | Severe Thunderstorm Warning | LWX | 38 min |
| Jun 28, 7:16 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jun 28, 8:53 PM EDT | Severe Thunderstorm Warning | LWX | 37 min |
| Jun 28, 8:58 PM EDT | Severe Thunderstorm Warning | LWX | 36 min |
| Jul 1, 1:56 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 1, 5:43 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Jul 14, 1:52 AM EDT | Heat Advisory | LWX | 17 hr |
| Jul 16, 4:17 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Jul 16, 6:07 PM EDT | Severe Thunderstorm Warning | LWX | 24 min |
| Jul 18, 1:42 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 18, 3:09 PM EDT | Mesoscale Discussion | SPC | 66 min |
| Jul 18, 3:45 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Jul 18, 4:05 PM EDT | Severe Thunderstorm Warning | LWX | 40 min |
| Jul 18, 4:08 PM EDT | Severe Thunderstorm Warning | LWX | 82 min |
| Jul 19, 10:21 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Jul 19, 11:14 PM EDT | Mesoscale Discussion | SPC | 91 min |
| Jul 19, 11:17 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Jul 23, 3:45 AM EDT | Heat Advisory | LWX | 16 hr |
| Jul 23, 2:34 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 24, 2:42 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 25, 3:05 PM EDT | Mesoscale Discussion | SPC | 115 min |
| Jul 25, 3:30 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 25, 5:02 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jul 25, 5:16 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Jul 25, 5:44 PM EDT | Severe Thunderstorm Warning | LWX | 18 min |
| Jul 25, 7:06 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jul 28, 4:45 AM EDT | Flash Flood Watch | LWX | 17 hr |
| Jul 28, 12:58 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 28, 1:27 PM EDT | Severe Thunderstorm Watch | SPC | 11 hr |
| Jul 28, 4:10 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Jul 28, 6:52 PM EDT | Mesoscale Discussion | SPC | 83 min |
| Jul 30, 12:11 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Jul 30, 5:54 PM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Jul 30, 7:00 PM EDT | Severe Thunderstorm Warning | LWX | 45 min |
| Jul 31, 3:34 PM EDT | Mesoscale Discussion | SPC | 116 min |
| Aug 6, 1:46 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 11, 3:32 AM EDT | Heat Advisory | LWX | 16 hr |
| Aug 11, 7:22 PM EDT | Excessive Heat Watch | LWX | 24 hr |
| Aug 11, 7:22 PM EDT | Heat Advisory | LWX | 24 hr |
| Aug 12, 7:32 PM EDT | Excessive Heat Watch | LWX | 21 hr |
| Aug 12, 7:32 PM EDT | Excessive Heat Warning | LWX | 25 hr |
| Aug 13, 4:37 PM EDT | Excessive Heat Warning | LWX | 26 hr |
| Aug 15, 1:58 PM EDT | Mesoscale Discussion | SPC | 92 min |
| Aug 15, 3:19 PM EDT | Heat Advisory | LWX | 27 hr |
| Aug 16, 1:40 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 16, 3:20 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Aug 16, 4:55 PM EDT | Mesoscale Discussion | SPC | 95 min |
| Aug 17, 11:55 AM EDT | Flash Flood Watch | LWX | 11 hr |
| Aug 17, 4:26 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Aug 17, 8:57 PM EDT | Severe Thunderstorm Warning | LWX | 33 min |
| Aug 17, 9:17 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| Aug 21, 1:31 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Sep 7, 3:06 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Sep 7, 5:06 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Sep 7, 5:39 PM EDT | Severe Thunderstorm Warning | LWX | 51 min |
| Sep 7, 6:00 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Sep 7, 6:44 PM EDT | Severe Thunderstorm Warning | LWX | 31 min |
| Sep 27, 5:30 PM EDT | Flash Flood Watch | LWX | 58 hr |
| Sep 28, 9:00 PM EDT | Coastal Flood Advisory | LWX | 4 days |
| Sep 29, 4:46 AM EDT | Areal Flood Warning | LWX | 6 hr |
| Oct 13, 6:11 AM EDT | Dense Fog Advisory | LWX | 3 hr |
| Oct 21, 2:56 PM EDT | Wind Advisory | LWX | 26 hr |
| Oct 25, 1:19 PM EDT | Frost Advisory | LWX | 20 hr |
| Nov 6, 2:35 PM EST | Freeze Warning | LWX | 15 hr |
| Nov 7, 2:22 PM EST | Frost Advisory | LWX | 18 hr |
| Nov 11, 12:23 PM EST | Frost Advisory | LWX | 21 hr |
| Nov 11, 12:23 PM EST | Freeze Watch | LWX | 15 hr |
| Nov 12, 3:19 AM EST | Freeze Warning | LWX | 30 hr |
| Nov 19, 3:09 AM EST | Wind Advisory | LWX | 17 hr |
| Nov 19, 2:09 PM EST | Fire Weather Watch | LWX | 14 hr |
| Nov 19, 8:10 PM EST | Wind Advisory | LWX | 44 hr |
| Nov 20, 3:46 AM EST | Fire Weather Watch | LWX | 23 hr |
| Nov 20, 3:46 AM EST | Red Flag Warning | LWX | 13 hr |
| Nov 29, 6:11 PM EST | Dense Fog Advisory | LWX | 15 hr |
| Dec 15, 4:04 AM EST | Wind Advisory | LWX | 8 hr |
| Dec 16, 3:48 AM EST | Winter Weather Advisory | LWX | 33 hr |
| Dec 24, 8:40 PM EST | Dense Fog Advisory | LWX | 9 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 archive20152017
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.