Alert archive / North Carolina / Forsyth County
Weather alerts in Forsyth County, North Carolina, 2009
97 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Forsyth County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 97
- Warnings
- 20
- Watches
- 19
- Advisories
- 39
- Busiest month
- May16 alerts
- Busiest day
- May 6, 20095 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 1 tornado warnings covering Forsyth County in 2009 had a tornado report inside them.
Forsyth County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 1 | 0 | 100% | 0 | ||
| Severe thunderstorm warnings | 10 | 7 | 30% | 8 | 88% | 22 min |
| Flash flood warnings | 3 | 1 | 67% | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Raleigh, NC: tornado warnings | 24 | 9 | 63% | 18 | 94% | 21 min |
| NWS Raleigh, NC: severe thunderstorm warnings | 333 | 181 | 46% | 356 | 88% | 23 min |
| NWS Raleigh, NC: flash flood warnings | 41 | 20 | 51% | 56 | 84% | 66 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 2, 9:10 AM EST | Winter Weather Advisory | RAH | 2 hr |
| Jan 3, 2:06 AM EST | Dense Fog Advisory | RAH | 9 hr |
| Jan 6, 11:34 PM EST | Dense Fog Advisory | RAH | 6 hr |
| Jan 7, 3:38 AM EST | Wind Advisory | RAH | 18 hr |
| Jan 15, 3:12 PM EST | Wind Chill Advisory | RAH | 18 hr |
| Jan 18, 9:37 PM EST | Dense Fog Advisory | RAH | 11 hr |
| Jan 19, 3:59 AM EST | Winter Storm Watch | RAH | 11 hr |
| Jan 19, 2:31 PM EST | Winter Weather Advisory | RAH | 22 hr |
| Feb 3, 12:30 PM EST | Winter Weather Advisory | RAH | 20 hr |
| Feb 11, 10:22 AM EST | Fire Weather Watch | RAH | 19 hr |
| Feb 11, 11:31 AM EST | Wind Advisory | RAH | 12 hr |
| Feb 12, 5:36 AM EST | Red Flag Warning | RAH | 14 hr |
| Feb 28, 4:24 AM EST | Winter Storm Watch | RAH | 24 hr |
| Feb 28, 10:17 PM EST | Winter Storm Warning | RAH | 33 hr |
| Mar 2, 11:02 AM EST | Winter Weather Advisory | RAH | 22 hr |
| Mar 26, 5:52 AM EDT | Dense Fog Advisory | RAH | 4 hr |
| Mar 26, 10:41 AM EDT | Dense Fog Advisory | RAH | 79 min |
| Mar 27, 5:34 AM EDT | Dense Fog Advisory | RAH | 4 hr |
| Apr 1, 10:18 PM EDT | Dense Fog Advisory | RAH | 12 hr |
| Apr 3, 4:10 AM EDT | Wind Advisory | RAH | 16 hr |
| Apr 3, 4:47 AM EDT | Mesoscale Discussion | SPC | 88 min |
| Apr 6, 3:47 PM EDT | Freeze Watch | RAH | 24 hr |
| Apr 7, 3:30 PM EDT | Freeze Warning | RAH | 16 hr |
| Apr 16, 3:30 PM EDT | Frost Advisory | RAH | 18 hr |
| Apr 21, 2:12 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Apr 22, 10:01 AM EDT | Red Flag Warning | RAH | 8 hr |
| May 6, 11:40 AM EDT | Mesoscale Discussion | SPC | 2 hr |
| May 6, 2:16 PM EDT | Tornado Watch | SPC | 6 hr |
| May 6, 5:57 PM EDT | Tornado Warning | RAH | 48 min |
| May 6, 6:39 PM EDT | Severe Thunderstorm Warning | RAH | 51 min |
| May 6, 7:29 PM EDT | Mesoscale Discussion | SPC | 91 min |
| May 6, 8:26 PM EDT | Tornado Watch | SPC | 8 hr |
| May 7, 5:17 AM EDT | Mesoscale Discussion | SPC | 118 min |
| May 7, 3:03 PM EDT | Mesoscale Discussion | SPC | 117 min |
| May 8, 11:37 PM EDT | Mesoscale Discussion | SPC | 53 min |
| May 9, 12:47 PM EDT | Mesoscale Discussion | SPC | 118 min |
| May 9, 1:17 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| May 9, 4:30 PM EDT | Mesoscale Discussion | SPC | 90 min |
| May 12, 5:33 AM EDT | Dense Fog Advisory | RAH | 3 hr |
| May 15, 6:34 PM EDT | Areal Flood Advisory | RAH | 3 hr |
| May 28, 3:49 PM EDT | Mesoscale Discussion | SPC | 56 min |
| May 29, 2:41 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 3, 12:41 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Jun 4, 11:21 AM EDT | Flash Flood Watch | RAH | 28 hr |
| Jun 4, 6:57 PM EDT | Areal Flood Advisory | RAH | 3 hr |
| Jun 5, 10:04 AM EDT | Flash Flood Warning | RAH | 3 hr |
| Jun 9, 2:31 PM EDT | Mesoscale Discussion | SPC | 89 min |
| Jun 9, 7:10 PM EDT | Severe Thunderstorm Warning | RAH | 50 min |
| Jun 10, 7:40 PM EDT | Severe Thunderstorm Warning | RAH | 55 min |
| Jun 11, 3:47 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jun 11, 5:19 PM EDT | Severe Thunderstorm Warning | RAH | 56 min |
| Jun 11, 5:58 PM EDT | Mesoscale Discussion | SPC | 62 min |
| Jun 12, 2:08 PM EDT | Mesoscale Discussion | SPC | 67 min |
| Jun 16, 4:20 AM EDT | Flash Flood Watch | RAH | 9 hr |
| Jun 17, 3:31 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 9, 6:16 PM EDT | Areal Flood Advisory | RAH | 3 hr |
| Jul 17, 9:52 AM EDT | Mesoscale Discussion | SPC | 83 min |
| Jul 17, 10:29 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jul 20, 3:51 AM EDT | Areal Flood Advisory | RAH | 86 min |
| Jul 20, 3:39 PM EDT | Severe Thunderstorm Warning | RAH | 36 min |
| Jul 20, 4:07 PM EDT | Severe Thunderstorm Warning | RAH | 38 min |
| Jul 20, 4:40 PM EDT | Severe Thunderstorm Warning | RAH | 50 min |
| Jul 27, 2:32 PM EDT | Severe Thunderstorm Warning | RAH | 43 min |
| Jul 31, 2:25 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Aug 11, 1:03 PM EDT | Mesoscale Discussion | SPC | 87 min |
| Aug 11, 3:21 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 13, 6:28 AM EDT | Dense Fog Advisory | RAH | 4 hr |
| Aug 20, 2:32 PM EDT | Severe Thunderstorm Warning | RAH | 38 min |
| Aug 31, 4:56 AM EDT | Areal Flood Advisory | RAH | 3 hr |
| Sep 19, 12:48 AM EDT | Dense Fog Advisory | RAH | 8 hr |
| Sep 28, 4:44 PM EDT | Severe Thunderstorm Warning | RAH | 32 min |
| Sep 28, 4:44 PM EDT | Mesoscale Discussion | SPC | 61 min |
| Oct 18, 2:37 AM EDT | Frost Advisory | RAH | 30 hr |
| Oct 19, 2:05 AM EDT | Frost Advisory | RAH | 31 hr |
| Oct 31, 7:50 AM EDT | Dense Fog Advisory | RAH | 3 hr |
| Nov 3, 9:56 PM EST | Frost Advisory | RAH | 11 hr |
| Nov 5, 2:52 PM EST | Frost Advisory | RAH | 18 hr |
| Nov 6, 3:23 AM EST | Freeze Watch | RAH | 6 hr |
| Nov 6, 9:03 AM EST | Freeze Warning | RAH | 24 hr |
| Nov 10, 2:35 PM EST | Flash Flood Watch | RAH | 54 hr |
| Nov 11, 3:37 AM EST | Wind Advisory | RAH | 50 hr |
| Nov 12, 5:40 AM EST | Areal Flood Advisory | RAH | 25 min |
| Nov 12, 6:00 AM EST | Flash Flood Warning | RAH | 3 hr |
| Nov 12, 9:04 AM EST | Flash Flood Warning | RAH | 4 hr |
| Nov 19, 9:39 PM EST | Dense Fog Advisory | RAH | 8 hr |
| Nov 26, 1:36 AM EST | Dense Fog Advisory | RAH | 8 hr |
| Dec 1, 3:27 PM EST | Flash Flood Watch | RAH | 30 hr |
| Dec 8, 9:10 PM EST | Wind Advisory | RAH | 24 hr |
| Dec 13, 7:54 PM EST | Dense Fog Advisory | RAH | 16 hr |
| Dec 15, 4:23 AM EST | Dense Fog Advisory | RAH | 6 hr |
| Dec 17, 3:44 AM EST | Winter Storm Watch | RAH | 13 hr |
| Dec 17, 4:25 PM EST | Winter Storm Warning | RAH | 40 hr |
| Dec 17, 4:25 PM EST | Winter Weather Advisory | RAH | 44 hr |
| Dec 18, 1:32 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 18, 7:22 PM EST | Mesoscale Discussion | SPC | 5 hr |
| Dec 24, 5:55 PM EST | Freezing Rain Advisory | RAH | 15 hr |
| Dec 30, 9:59 PM EST | Winter Weather Advisory | RAH | 8 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 | 10 |
| Tornado Warning | 1 |
| Severe Thunderstorm Watch | 7 |
| Tornado Watch | 2 |
| Mesoscale Discussion | 19 |
| Flooding | |
| Flash Flood Warning | 3 |
| Flash Flood Watch | 4 |
| Areal Flood Advisory | 6 |
| Winter | |
| Winter Storm Warning | 2 |
| Winter Storm Watch | 3 |
| Freezing Rain Advisory | 1 |
| Winter Weather Advisory | 6 |
| Cold | |
| Freeze Warning | 2 |
| Freeze Watch | 2 |
| Frost Advisory | 5 |
| Wind Chill Advisory | 1 |
| Wind and dust | |
| Wind Advisory | 5 |
| Fire | |
| Red Flag Warning | 2 |
| Fire Weather Watch | 1 |
| Fog and smoke | |
| Dense Fog Advisory | 15 |
The busiest days
Days with the most alerts issued, by UTC date.
Nearby
Alerts in force nowTornadoes on recordForecastThe radar archive20082010
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.