Alert archive / Pennsylvania / Mercer County
Weather alerts in Mercer County, Pennsylvania, 2009
78 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.
Mercer County and its neighbors
Each county as a circle sized by its count in 2009. Tap one for its archive.
- Alerts
- 78
- Warnings
- 19
- Watches
- 9
- Advisories
- 32
- Busiest month
- January17 alerts
- Busiest day
- February 12, 20094 alerts
Over time
By month
Warning verification
How often warnings here had a storm report inside them, and how much warning the reports had.
Mercer County, 2009
| Warnings | With a report | False alarm ratio | Reports | Inside a warning | Mean lead time | |
|---|---|---|---|---|---|---|
| Tornado warnings | 0 | 0 | ||||
| Severe thunderstorm warnings | 9 | 7 | 22% | 5 | 80% | 35 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 Pittsburgh, PA: tornado warnings | 14 | 0 | 100% | 0 | ||
| NWS Pittsburgh, PA: severe thunderstorm warnings | 115 | 66 | 43% | 119 | 78% | 25 min |
| NWS Pittsburgh, PA: flash flood warnings | 9 | 6 | 33% | 11 | 91% | 72 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, 3:50 PM EST | Winter Weather Advisory | PBZ | 36 hr |
| Jan 5, 9:46 PM EST | Winter Storm Warning | PBZ | 36 hr |
| Jan 6, 5:17 PM EST | Mesoscale Discussion | SPC | 4 hr |
| Jan 7, 3:31 PM EST | Winter Weather Advisory | PBZ | 37 hr |
| Jan 8, 2:40 PM EST | Winter Storm Watch | PBZ | 22 hr |
| Jan 9, 12:32 PM EST | Winter Storm Warning | PBZ | 31 hr |
| Jan 9, 12:32 PM EST | Winter Weather Advisory | PBZ | 34 hr |
| Jan 10, 6:33 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 14, 3:46 AM EST | Winter Weather Advisory | PBZ | 38 hr |
| Jan 14, 2:36 PM EST | Wind Chill Advisory | PBZ | 69 hr |
| Jan 15, 3:31 AM EST | Lake Effect Snow Advisory | PBZ | 17 hr |
| Jan 17, 2:36 PM EST | Winter Weather Advisory | PBZ | 45 hr |
| Jan 18, 9:13 AM EST | Winter Storm Warning | PBZ | 13 hr |
| Jan 26, 12:35 PM EST | Winter Storm Watch | PBZ | 23 hr |
| Jan 27, 11:48 AM EST | Winter Storm Warning | PBZ | 31 hr |
| Jan 28, 12:31 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Jan 28, 7:40 AM EST | Mesoscale Discussion | SPC | 5 hr |
| Feb 4, 2:18 PM EST | Wind Chill Advisory | PBZ | 20 hr |
| Feb 10, 11:18 AM EST | Flood Watch | PBZ | 27 hr |
| Feb 10, 3:10 PM EST | High Wind Watch | PBZ | 20 hr |
| Feb 11, 3:46 AM EST | High Wind Warning | PBZ | 39 hr |
| Feb 11, 12:24 PM EST | Areal Flood Warning | PBZ | 24 hr |
| Feb 11, 5:53 PM EST | Severe Thunderstorm Watch | SPC | 4 hr |
| Feb 11, 7:26 PM EST | Severe Thunderstorm Warning | PBZ | 64 min |
| Feb 11, 8:00 PM EST | Mesoscale Discussion | SPC | 60 min |
| Feb 11, 8:11 PM EST | Severe Thunderstorm Warning | PBZ | 46 min |
| Feb 12, 4:15 AM EST | Wind Advisory | PBZ | 15 hr |
| Feb 18, 4:07 PM EST | Lake Effect Snow Advisory | PBZ | 42 hr |
| Feb 22, 3:06 AM EST | Lake Effect Snow Advisory | PBZ | 36 hr |
| Mar 2, 2:27 PM EST | Wind Chill Advisory | PBZ | 13 hr |
| Mar 10, 3:16 AM EDT | Flood Watch | PBZ | 23 hr |
| Mar 17, 6:59 AM EDT | Dense Fog Advisory | PBZ | 5 hr |
| Mar 27, 5:26 AM EDT | Dense Fog Advisory | PBZ | 6 hr |
| Apr 3, 11:45 AM EDT | Wind Advisory | PBZ | 16 hr |
| Apr 6, 2:55 PM EDT | Lake Effect Snow Advisory | PBZ | 41 hr |
| May 1, 6:36 PM EDT | Mesoscale Discussion | SPC | 54 min |
| May 9, 3:16 AM EDT | Wind Advisory | PBZ | 17 hr |
| May 16, 12:05 PM EDT | Mesoscale Discussion | SPC | 55 min |
| May 16, 1:00 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| May 17, 3:04 AM EDT | Freeze Warning | PBZ | 29 hr |
| May 18, 3:04 PM EDT | Frost Advisory | PBZ | 17 hr |
| Jun 1, 9:32 PM EDT | Mesoscale Discussion | SPC | 58 min |
| Jun 17, 5:24 PM EDT | Severe Thunderstorm Warning | PBZ | 66 min |
| Jun 20, 1:57 AM EDT | Severe Thunderstorm Warning | PBZ | 63 min |
| Jul 11, 10:31 AM EDT | Mesoscale Discussion | SPC | 59 min |
| Jul 11, 7:06 PM EDT | Mesoscale Discussion | SPC | 114 min |
| Jul 21, 1:56 PM EDT | Mesoscale Discussion | SPC | 64 min |
| Jul 21, 4:34 PM EDT | Severe Thunderstorm Warning | PBZ | 56 min |
| Jul 23, 12:09 AM EDT | Areal Flood Advisory | PBZ | 6 hr |
| Jul 26, 12:56 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 10, 2:26 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 10, 3:13 PM EDT | Severe Thunderstorm Watch | SPC | 8 hr |
| Aug 10, 4:27 PM EDT | Severe Thunderstorm Warning | PBZ | 63 min |
| Aug 10, 4:53 PM EDT | Severe Thunderstorm Warning | PBZ | 37 min |
| Aug 11, 12:39 PM EDT | Mesoscale Discussion | SPC | 2 hr |
| Aug 11, 1:39 PM EDT | Areal Flood Advisory | PBZ | 3 hr |
| Aug 13, 3:17 AM EDT | Dense Fog Advisory | PBZ | 7 hr |
| Aug 18, 2:32 PM EDT | Mesoscale Discussion | SPC | 88 min |
| Aug 20, 2:41 PM EDT | Severe Thunderstorm Watch | SPC | 7 hr |
| Aug 20, 6:20 PM EDT | Mesoscale Discussion | SPC | 55 min |
| Aug 20, 6:28 PM EDT | Severe Thunderstorm Warning | PBZ | 62 min |
| Aug 20, 7:50 PM EDT | Severe Thunderstorm Warning | PBZ | 55 min |
| Sep 13, 7:24 AM EDT | Dense Fog Advisory | PBZ | 3 hr |
| Sep 27, 3:06 PM EDT | Wind Advisory | PBZ | 28 hr |
| Sep 30, 3:27 PM EDT | Frost Advisory | PBZ | 18 hr |
| Oct 6, 8:33 PM EDT | Wind Advisory | PBZ | 19 hr |
| Oct 11, 2:18 PM EDT | Frost Advisory | PBZ | 16 hr |
| Oct 13, 3:24 AM EDT | Freeze Warning | PBZ | 30 hr |
| Dec 8, 2:35 PM EST | Winter Weather Advisory | PBZ | 18 hr |
| Dec 8, 2:42 PM EST | Wind Advisory | PBZ | 22 hr |
| Dec 9, 11:02 AM EST | Mesoscale Discussion | SPC | 88 min |
| Dec 9, 1:00 PM EST | High Wind Warning | PBZ | 8 hr |
| Dec 12, 2:48 PM EST | Winter Weather Advisory | PBZ | 22 hr |
| Dec 13, 5:16 AM EST | Mesoscale Discussion | SPC | 4 hr |
| Dec 13, 11:25 AM EST | Winter Weather Advisory | PBZ | 35 min |
| Dec 24, 2:20 PM EST | Winter Weather Advisory | PBZ | 22 hr |
| Dec 25, 7:14 AM EST | Winter Storm Warning | PBZ | 9 hr |
| Dec 27, 3:49 PM EST | Winter Weather Advisory | PBZ | 43 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 | 9 |
| Severe Thunderstorm Watch | 4 |
| Mesoscale Discussion | 18 |
| Flooding | |
| Areal Flood Warning | 1 |
| Flood Watch | 2 |
| Areal Flood Advisory | 2 |
| Winter | |
| Winter Storm Warning | 5 |
| Winter Storm Watch | 2 |
| Lake Effect Snow Advisory | 4 |
| Winter Weather Advisory | 10 |
| Cold | |
| Freeze Warning | 2 |
| Frost Advisory | 3 |
| Wind Chill Advisory | 3 |
| Wind and dust | |
| High Wind Warning | 2 |
| High Wind Watch | 1 |
| Wind Advisory | 6 |
| Fog and smoke | |
| Dense Fog Advisory | 4 |
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.