Alert archive / Virginia / Fairfax County
Weather alerts in Fairfax County, Virginia, 2015
168 weather alerts in 2015, 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 2015. Tap one for its archive.
- Alerts
- 168
- Warnings
- 63
- Watches
- 23
- Advisories
- 50
- Busiest month
- June57 alerts
- Busiest day
- June 23, 201510 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
0 of 3 tornado warnings covering Fairfax County in 2015 had a tornado report inside them.
Fairfax County, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 3 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 41 | 35 | 15% | 49 | 80% | 18 min |
| Flash flood warnings | 6 | 6 | 0% | 18 | 94% | 40 min |
Each office's whole area, 2015
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Baltimore/Washington: tornado warnings | 17 | 2 | 88% | 4 | 50% | 5 min |
| NWS Baltimore/Washington: severe thunderstorm warnings | 235 | 153 | 35% | 526 | 75% | 16 min |
| NWS Baltimore/Washington: flash flood warnings | 89 | 47 | 47% | 138 | 74% | 64 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, 1:59 PM EST | Winter Weather Advisory | LWX | 53 hr |
| Jan 6, 7:01 AM EST | Winter Storm Warning | LWX | 12 hr |
| Jan 6, 2:58 PM EST | Wind Chill Advisory | LWX | 50 hr |
| Jan 8, 8:18 AM EST | Wind Chill Advisory | LWX | 42 min |
| Jan 11, 3:03 PM EST | Freezing Rain Advisory | LWX | 22 hr |
| Jan 13, 4:59 PM EST | Winter Weather Advisory | LWX | 22 hr |
| Jan 20, 2:55 PM EST | Winter Weather Advisory | LWX | 26 hr |
| Jan 21, 6:32 PM EST | Winter Weather Advisory | LWX | 15 hr |
| Jan 23, 4:19 AM EST | Winter Weather Advisory | LWX | 32 hr |
| Jan 25, 9:38 AM EST | Winter Weather Advisory | LWX | 47 hr |
| Jan 29, 3:56 AM EST | Winter Weather Advisory | LWX | 32 hr |
| Jan 29, 9:44 PM EST | Wind Advisory | LWX | 26 hr |
| Feb 1, 10:39 PM EST | Wind Advisory | LWX | 23 hr |
| Feb 9, 8:47 AM EST | Winter Weather Advisory | LWX | 26 hr |
| Feb 12, 3:33 AM EST | Wind Advisory | LWX | 21 hr |
| Feb 12, 3:48 AM EST | Wind Chill Advisory | LWX | 32 hr |
| Feb 13, 3:25 AM EST | High Wind Watch | LWX | 24 hr |
| Feb 13, 2:56 PM EST | Winter Weather Advisory | LWX | 33 hr |
| Feb 14, 3:17 AM EST | High Wind Warning | LWX | 32 hr |
| Feb 14, 3:17 AM EST | Wind Advisory | LWX | 36 hr |
| Feb 14, 3:44 AM EST | Wind Chill Warning | LWX | 54 hr |
| Feb 14, 3:44 AM EST | Wind Chill Advisory | LWX | 16 hr |
| Feb 14, 7:23 PM EST | Wind Chill Advisory | LWX | 38 hr |
| Feb 15, 3:12 PM EST | Winter Storm Watch | LWX | 13 hr |
| Feb 15, 9:53 PM EST | Winter Storm Warning | LWX | 33 hr |
| Feb 17, 8:45 PM EST | Winter Weather Advisory | LWX | 28 hr |
| Feb 18, 4:13 AM EST | Wind Chill Advisory | LWX | 56 hr |
| Feb 20, 3:37 PM EST | Winter Storm Warning | LWX | 41 hr |
| Feb 20, 3:37 PM EST | Winter Weather Advisory | LWX | 41 hr |
| Feb 25, 4:03 AM EST | Winter Weather Advisory | LWX | 32 hr |
| Feb 28, 2:53 PM EST | Winter Weather Advisory | LWX | 38 hr |
| Mar 1, 3:42 AM EST | Winter Storm Warning | LWX | 18 hr |
| Mar 2, 4:51 AM EST | Dense Fog Advisory | LWX | 4 hr |
| Mar 2, 3:37 PM EST | Winter Weather Advisory | LWX | 30 hr |
| Mar 3, 2:50 PM EST | Winter Storm Watch | LWX | 23 hr |
| Mar 4, 4:51 AM EST | Winter Storm Warning | LWX | 39 hr |
| Mar 4, 6:44 PM EST | Dense Fog Advisory | LWX | 2 hr |
| Mar 5, 7:58 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Mar 5, 11:55 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Mar 10, 5:23 PM EDT | Dense Fog Advisory | LWX | 13 hr |
| Mar 25, 3:03 AM EDT | Freezing Rain Advisory | LWX | 8 hr |
| Mar 26, 6:12 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Mar 31, 11:47 AM EDT | Wind Advisory | LWX | 10 hr |
| Apr 11, 1:54 PM EDT | Frost Advisory | LWX | 19 hr |
| Apr 19, 4:10 AM EDT | Flood Watch | LWX | 26 hr |
| Apr 20, 1:54 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Apr 20, 3:08 PM EDT | Tornado Watch | SPC | 9 hr |
| Apr 20, 5:01 PM EDT | Mesoscale Discussion | SPC | 119 min |
| Apr 20, 7:42 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Apr 20, 8:02 PM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Apr 20, 8:16 PM EDT | Severe Thunderstorm Warning | LWX | 44 min |
| Apr 20, 10:40 PM EDT | Coastal Flood Advisory | LWX | 3 hr |
| Apr 22, 12:32 PM EDT | Mesoscale Discussion | SPC | 118 min |
| Apr 24, 2:35 PM EDT | Frost Advisory | LWX | 18 hr |
| May 6, 3:19 PM EDT | Severe Thunderstorm Warning | LWX | 41 min |
| May 6, 3:21 PM EDT | Mesoscale Discussion | SPC | 114 min |
| May 6, 4:04 PM EDT | Severe Thunderstorm Warning | LWX | 23 min |
| May 16, 1:35 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 16, 5:02 PM EDT | Severe Thunderstorm Warning | LWX | 43 min |
| May 16, 5:48 PM EDT | Severe Thunderstorm Warning | LWX | 27 min |
| May 27, 12:21 PM EDT | Mesoscale Discussion | SPC | 54 min |
| May 27, 12:54 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 27, 2:59 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 1, 4:22 AM EDT | Flash Flood Watch | LWX | 23 hr |
| Jun 1, 6:15 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 1, 6:20 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Jun 1, 6:28 PM EDT | Severe Thunderstorm Warning | LWX | 32 min |
| Jun 1, 6:41 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jun 8, 2:34 PM EDT | Tornado Watch | SPC | 5 hr |
| Jun 8, 4:39 PM EDT | Severe Thunderstorm Warning | LWX | 36 min |
| Jun 8, 4:46 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jun 8, 6:43 PM EDT | Severe Thunderstorm Warning | LWX | 32 min |
| Jun 8, 7:07 PM EDT | Mesoscale Discussion | SPC | 53 min |
| Jun 8, 7:12 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Jun 8, 7:24 PM EDT | Severe Thunderstorm Watch | SPC | 2 hr |
| Jun 12, 2:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Jun 14, 2:06 PM EDT | Mesoscale Discussion | SPC | 84 min |
| Jun 14, 5:35 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Jun 16, 12:15 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 18, 4:00 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 18, 4:30 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 18, 4:48 PM EDT | Severe Thunderstorm Warning | LWX | 42 min |
| Jun 18, 4:51 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Jun 18, 5:11 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jun 18, 5:35 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Jun 19, 3:11 PM EDT | Flash Flood Watch | LWX | 38 hr |
| Jun 20, 1:36 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Jun 20, 2:23 PM EDT | Severe Thunderstorm Watch | SPC | 9 hr |
| Jun 20, 6:11 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jun 20, 6:24 PM EDT | Mesoscale Discussion | SPC | 96 min |
| Jun 20, 7:11 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jun 20, 7:21 PM EDT | Severe Thunderstorm Warning | LWX | 39 min |
| Jun 20, 7:32 PM EDT | Tornado Warning | LWX | 28 min |
| Jun 20, 7:48 PM EDT | Severe Thunderstorm Warning | LWX | 27 min |
| Jun 20, 8:10 PM EDT | Severe Thunderstorm Warning | LWX | 35 min |
| Jun 20, 8:21 PM EDT | Tornado Warning | LWX | 24 min |
| Jun 20, 8:33 PM EDT | Tornado Warning | LWX | 1 min |
| Jun 20, 8:50 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jun 20, 9:04 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jun 20, 11:25 PM EDT | Coastal Flood Advisory | LWX | 3 hr |
| Jun 20, 11:35 PM EDT | Areal Flood Warning | LWX | 11 hr |
| Jun 23, 3:51 AM EDT | Heat Advisory | LWX | 15 hr |
| Jun 23, 1:45 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 23, 4:09 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 23, 5:47 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Jun 23, 6:01 PM EDT | Severe Thunderstorm Warning | LWX | 29 min |
| Jun 23, 6:27 PM EDT | Severe Thunderstorm Warning | LWX | 48 min |
| Jun 23, 6:35 PM EDT | Severe Thunderstorm Warning | LWX | 25 min |
| Jun 23, 6:46 PM EDT | Severe Thunderstorm Warning | LWX | 29 min |
| Jun 23, 7:14 PM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Jun 23, 7:41 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jun 23, 8:00 PM EDT | Severe Thunderstorm Warning | LWX | 30 min |
| Jun 26, 4:20 AM EDT | Flash Flood Watch | LWX | 40 hr |
| Jun 27, 12:56 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Jun 27, 2:38 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jun 27, 3:14 PM EDT | Severe Thunderstorm Warning | LWX | 31 min |
| Jun 27, 8:48 PM EDT | Areal Flood Warning | LWX | 117 min |
| Jun 30, 12:31 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 2:22 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 4:15 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jun 30, 11:08 PM EDT | Coastal Flood Advisory | LWX | 11 hr |
| Jun 30, 11:55 PM EDT | Severe Thunderstorm Warning | LWX | 35 min |
| Jul 1, 12:11 AM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Jul 1, 12:33 AM EDT | Severe Thunderstorm Warning | LWX | 27 min |
| Jul 1, 12:47 AM EDT | Severe Thunderstorm Warning | LWX | 28 min |
| Jul 1, 8:27 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jul 4, 9:53 PM EDT | Dense Fog Advisory | LWX | 12 hr |
| Jul 6, 1:01 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 8, 6:37 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jul 8, 9:23 PM EDT | Areal Flood Warning | LWX | 3 hr |
| Jul 8, 11:40 PM EDT | Areal Flood Warning | LWX | 6 hr |
| Jul 9, 4:38 PM EDT | Flash Flood Watch | LWX | 3 hr |
| Jul 10, 2:17 PM EDT | Flash Flood Watch | LWX | 16 hr |
| Jul 14, 5:05 AM EDT | Flash Flood Watch | LWX | 16 hr |
| Jul 14, 6:10 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 14, 6:44 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jul 14, 9:26 PM EDT | Mesoscale Discussion | SPC | 94 min |
| Jul 18, 3:11 PM EDT | Heat Advisory | LWX | 29 hr |
| Jul 20, 3:41 AM EDT | Heat Advisory | LWX | 16 hr |
| Jul 27, 3:40 PM EDT | Severe Thunderstorm Warning | LWX | 36 min |
| Jul 27, 3:44 PM EDT | Flash Flood Warning | LWX | 3 hr |
| Jul 30, 1:57 PM EDT | Severe Thunderstorm Warning | LWX | 34 min |
| Aug 4, 4:14 AM EDT | Severe Thunderstorm Warning | LWX | 46 min |
| Aug 4, 3:48 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 4, 5:40 PM EDT | Severe Thunderstorm Warning | LWX | 24 min |
| Aug 4, 6:39 PM EDT | Severe Thunderstorm Warning | LWX | 18 min |
| Aug 11, 1:30 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Aug 20, 4:29 AM EDT | Flash Flood Watch | LWX | 18 hr |
| Aug 20, 3:45 PM EDT | Mesoscale Discussion | SPC | 3 hr |
| Sep 2, 3:35 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Sep 19, 6:16 AM EDT | Dense Fog Advisory | LWX | 4 hr |
| Sep 24, 4:56 AM EDT | Coastal Flood Advisory | LWX | 6 days |
| Sep 29, 6:20 PM EDT | Mesoscale Discussion | SPC | 85 min |
| Oct 1, 4:19 AM EDT | Flash Flood Watch | LWX | 50 hr |
| Oct 17, 3:34 AM EDT | Freeze Watch | LWX | 31 hr |
| Oct 17, 2:18 PM EDT | Frost Advisory | LWX | 19 hr |
| Oct 18, 10:38 AM EDT | Freeze Warning | LWX | 22 hr |
| Dec 1, 10:47 PM EST | Dense Fog Advisory | LWX | 17 hr |
| Dec 6, 9:28 PM EST | Dense Fog Advisory | LWX | 6 hr |
| Dec 9, 6:14 AM EST | Dense Fog Advisory | LWX | 7 hr |
| Dec 10, 3:16 AM EST | Dense Fog Advisory | LWX | 8 hr |
| Dec 17, 9:57 PM EST | Dense Fog Advisory | LWX | 5 hr |
| Dec 23, 5:57 PM EST | Areal Flood Warning | LWX | 2 hr |
| Dec 24, 3:44 AM EST | Flash Flood Watch | LWX | 10 hr |
| Dec 25, 4:14 AM EST | Dense Fog Advisory | LWX | 9 hr |
| Dec 25, 1:19 PM EST | Flash Flood Watch | LWX | 6 hr |
| Dec 30, 12:08 AM EST | Dense Fog Advisory | LWX | 11 hr |
| Dec 31, 1:18 AM 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.
| Product | Alerts |
|---|---|
| Severe storms | |
| Severe Thunderstorm Warning | 41 |
| Tornado Warning | 3 |
| Severe Thunderstorm Watch | 6 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 32 |
| Flooding | |
| Areal Flood Warning | 5 |
| Flash Flood Warning | 6 |
| Flash Flood Watch | 10 |
| Flood Watch | 1 |
| Winter | |
| Winter Storm Warning | 5 |
| Winter Storm Watch | 2 |
| Freezing Rain Advisory | 2 |
| Winter Weather Advisory | 14 |
| Heat | |
| Heat Advisory | 3 |
| Cold | |
| Freeze Warning | 1 |
| Wind Chill Warning | 1 |
| Freeze Watch | 1 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 6 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 5 |
| Fog and smoke | |
| Dense Fog Advisory | 13 |
| Coast and beach | |
| Coastal Flood Advisory | 4 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20142016
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.