Alert archive / Vermont / Chittenden County
Weather alerts in Chittenden County, Vermont, 2009
106 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Chittenden County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 106
- Warnings
- 21
- Watches
- 17
- Advisories
- 30
- Busiest month
- July25 alerts
- Busiest day
- June 30, 20098 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Chittenden County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 11 | 7 | 36% | 11 | 91% | 36 min |
| Flash flood warnings | 0 | 0 |
Each office's whole area, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| NWS Burlington, VT: tornado warnings | 2 | 1 | 50% | 2 | 50% | 12 min |
| NWS Burlington, VT: severe thunderstorm warnings | 55 | 26 | 53% | 49 | 82% | 22 min |
| NWS Burlington, VT: flash flood warnings | 2 | 2 | 0% | 10 | 60% | 51 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 3, 7:36 AM EST | Winter Weather Advisory | BTV | 98 min |
| Jan 3, 9:14 AM EST | Winter Storm Warning | BTV | 3 hr |
| Jan 6, 3:50 AM EST | Winter Storm Watch | BTV | 7 hr |
| Jan 6, 10:46 AM EST | Winter Storm Warning | BTV | 42 hr |
| Jan 7, 11:39 AM EST | Mesoscale Discussion | SPC | 6 hr |
| Jan 13, 3:40 AM EST | Winter Weather Advisory | BTV | 23 hr |
| Jan 13, 3:59 PM EST | Wind Chill Advisory | BTV | 19 hr |
| Jan 18, 2:57 AM EST | Winter Weather Advisory | BTV | 12 hr |
| Jan 26, 2:46 PM EST | Winter Storm Watch | BTV | 14 hr |
| Jan 27, 4:46 AM EST | Winter Storm Warning | BTV | 47 hr |
| Jan 28, 12:26 PM EST | Mesoscale Discussion | SPC | 6 hr |
| Feb 11, 2:10 PM EST | Flood Watch | BTV | 38 hr |
| Feb 20, 1:29 AM EST | Winter Weather Advisory | BTV | 20 hr |
| Feb 21, 3:27 AM EST | Winter Storm Watch | BTV | 12 hr |
| Feb 21, 3:08 PM EST | Winter Storm Warning | BTV | 55 hr |
| Feb 26, 2:53 PM EST | Wind Advisory | BTV | 24 hr |
| Mar 1, 3:00 AM EST | Winter Storm Watch | BTV | 11 hr |
| Mar 1, 2:17 PM EST | Winter Storm Warning | BTV | 31 hr |
| Mar 1, 2:17 PM EST | Winter Weather Advisory | BTV | 31 hr |
| Mar 10, 4:25 AM EDT | Flood Watch | BTV | 35 hr |
| May 9, 12:43 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| May 9, 2:56 PM EDT | Mesoscale Discussion | SPC | 94 min |
| May 9, 3:37 PM EDT | Severe Thunderstorm Warning | BTV | 53 min |
| May 9, 4:21 PM EDT | Areal Flood Advisory | BTV | 2 hr |
| May 11, 3:02 AM EDT | Frost Advisory | BTV | 28 hr |
| May 12, 11:40 AM EDT | Frost Advisory | BTV | 19 hr |
| May 13, 6:36 AM EDT | Wind Advisory | BTV | 37 hr |
| May 17, 4:20 AM EDT | Freeze Warning | BTV | 23 hr |
| May 18, 4:10 AM EDT | Frost Advisory | BTV | 27 hr |
| May 25, 4:10 AM EDT | Frost Advisory | BTV | 27 hr |
| May 25, 4:10 AM EDT | Freeze Warning | BTV | 27 hr |
| May 27, 3:30 AM EDT | Flood Watch | BTV | 55 hr |
| May 31, 4:00 AM EDT | Frost Advisory | BTV | 26 hr |
| May 31, 6:47 PM EDT | Special Weather Statement | BTV | 58 min |
| May 31, 7:19 PM EDT | Special Weather Statement | BTV | 56 min |
| Jun 15, 1:02 PM EDT | Special Weather Statement | BTV | 28 min |
| Jun 21, 4:35 PM EDT | Special Weather Statement | BTV | 55 min |
| Jun 25, 4:30 PM EDT | Severe Thunderstorm Warning | BTV | 30 min |
| Jun 26, 12:06 PM EDT | Mesoscale Discussion | SPC | 54 min |
| Jun 26, 12:13 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Jun 26, 4:50 PM EDT | Severe Thunderstorm Warning | BTV | 25 min |
| Jun 26, 5:02 PM EDT | Severe Thunderstorm Warning | BTV | 43 min |
| Jun 26, 5:13 PM EDT | Severe Thunderstorm Warning | BTV | 47 min |
| Jun 26, 5:40 PM EDT | Severe Thunderstorm Warning | BTV | 50 min |
| Jun 26, 6:00 PM EDT | Mesoscale Discussion | SPC | 60 min |
| Jun 30, 10:57 AM EDT | Mesoscale Discussion | SPC | 93 min |
| Jun 30, 11:37 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Jun 30, 2:02 PM EDT | Special Weather Statement | BTV | 58 min |
| Jun 30, 2:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Jun 30, 3:23 PM EDT | Flash Flood Watch | BTV | 8 hr |
| Jun 30, 4:25 PM EDT | Mesoscale Discussion | SPC | 65 min |
| Jun 30, 5:58 PM EDT | Severe Thunderstorm Warning | BTV | 79 min |
| Jun 30, 6:06 PM EDT | Mesoscale Discussion | SPC | 54 min |
| Jul 1, 2:55 PM EDT | Severe Thunderstorm Watch | SPC | 4 hr |
| Jul 1, 5:44 PM EDT | Mesoscale Discussion | SPC | 61 min |
| Jul 2, 4:10 AM EDT | Flash Flood Watch | BTV | 17 hr |
| Jul 4, 2:31 PM EDT | Areal Flood Advisory | BTV | 2 hr |
| Jul 6, 4:53 PM EDT | Special Weather Statement | BTV | 52 min |
| Jul 6, 5:40 PM EDT | Special Weather Statement | BTV | 50 min |
| Jul 7, 2:23 PM EDT | Special Weather Statement | BTV | 52 min |
| Jul 7, 3:07 PM EDT | Severe Thunderstorm Warning | BTV | 53 min |
| Jul 7, 4:15 PM EDT | Special Weather Statement | BTV | 60 min |
| Jul 11, 5:44 PM EDT | Special Weather Statement | BTV | 61 min |
| Jul 16, 1:39 PM EDT | Severe Thunderstorm Watch | SPC | 6 hr |
| Jul 16, 3:54 PM EDT | Special Weather Statement | BTV | 51 min |
| Jul 16, 4:20 PM EDT | Severe Thunderstorm Warning | BTV | 55 min |
| Jul 16, 4:34 PM EDT | Special Weather Statement | BTV | 56 min |
| Jul 16, 4:42 PM EDT | Severe Thunderstorm Warning | BTV | 52 min |
| Jul 16, 4:55 PM EDT | Mesoscale Discussion | SPC | 65 min |
| Jul 16, 5:09 PM EDT | Severe Thunderstorm Warning | BTV | 51 min |
| Jul 16, 6:16 PM EDT | Mesoscale Discussion | SPC | 59 min |
| Jul 26, 1:13 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Jul 27, 11:02 AM EDT | Mesoscale Discussion | SPC | 118 min |
| Jul 29, 2:22 PM EDT | Mesoscale Discussion | SPC | 23 min |
| Jul 29, 2:28 PM EDT | Flash Flood Watch | BTV | 15 hr |
| Jul 29, 4:20 PM EDT | Special Weather Statement | BTV | 55 min |
| Jul 29, 4:50 PM EDT | Special Weather Statement | BTV | 55 min |
| Jul 29, 5:59 PM EDT | Special Weather Statement | BTV | 61 min |
| Jul 31, 8:48 PM EDT | Dense Fog Advisory | BTV | 10 hr |
| Aug 2, 4:58 PM EDT | Areal Flood Advisory | BTV | 2 hr |
| Aug 18, 6:22 PM EDT | Special Weather Statement | BTV | 53 min |
| Aug 21, 10:01 AM EDT | Mesoscale Discussion | SPC | 119 min |
| Aug 21, 10:47 AM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Sep 19, 3:28 AM EDT | Frost Advisory | BTV | 28 hr |
| Sep 19, 3:28 AM EDT | Freeze Warning | BTV | 28 hr |
| Sep 23, 1:18 PM EDT | Mesoscale Discussion | SPC | 57 min |
| Sep 23, 3:11 PM EDT | Special Weather Statement | BTV | 49 min |
| Sep 25, 3:24 PM EDT | Frost Advisory | BTV | 16 hr |
| Sep 25, 3:24 PM EDT | Freeze Warning | BTV | 16 hr |
| Sep 28, 7:16 PM EDT | Special Weather Statement | BTV | 59 min |
| Oct 11, 3:23 AM EDT | Frost Advisory | BTV | 28 hr |
| Oct 30, 3:27 PM EDT | Wind Advisory | BTV | 28 hr |
| Nov 27, 4:16 AM EST | Winter Weather Advisory | BTV | 27 hr |
| Nov 28, 3:44 AM EST | Wind Advisory | BTV | 10 hr |
| Dec 8, 2:12 AM EST | Winter Weather Advisory | BTV | 37 hr |
| Dec 8, 3:06 AM EST | High Wind Watch | BTV | 13 hr |
| Dec 8, 3:48 PM EST | High Wind Warning | BTV | 27 hr |
| Dec 9, 6:33 AM EST | Mesoscale Discussion | SPC | 3 hr |
| Dec 10, 9:49 AM EST | Winter Weather Advisory | BTV | 33 hr |
| Dec 10, 10:38 AM EST | Special Weather Statement | BTV | 112 min |
| Dec 11, 6:05 PM EST | Special Weather Statement | BTV | 55 min |
| Dec 13, 11:10 AM EST | Winter Weather Advisory | BTV | 11 hr |
| Dec 26, 3:24 PM EST | Winter Weather Advisory | BTV | 15 hr |
| Dec 27, 12:13 AM EST | Wind Advisory | BTV | 7 hr |
| Dec 27, 3:33 PM EST | Winter Weather Advisory | BTV | 29 hr |
| Dec 29, 2:09 AM EST | Wind Chill Advisory | BTV | 21 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 | 11 |
| Severe Thunderstorm Watch | 6 |
| Mesoscale Discussion | 18 |
| Special Weather Statement | 20 |
| Flooding | |
| Flash Flood Watch | 3 |
| Flood Watch | 3 |
| Areal Flood Advisory | 3 |
| Winter | |
| Winter Storm Warning | 5 |
| Winter Storm Watch | 4 |
| Winter Weather Advisory | 11 |
| Cold | |
| Freeze Warning | 4 |
| Frost Advisory | 8 |
| Wind Chill Advisory | 2 |
| Wind and dust | |
| High Wind Warning | 1 |
| High Wind Watch | 1 |
| Wind Advisory | 5 |
| Fog and smoke | |
| Dense Fog Advisory | 1 |
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.