Alert archive / Pennsylvania / Union County

Weather alerts in Union County, Pennsylvania, 2009

119 weather alerts in 2009, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Union County and its neighbors

Each county as a circle sized by its count in 2009. Tap one for its archive.

Alerts
119
Warnings
20
Watches
17
Advisories
37
Busiest month
July24 alerts
Busiest day
August 9, 20096 alerts

Over time

By month

Warning verification

How often warnings here had a storm report inside them, and how much warning the reports had.

1 of 1 tornado warnings covering Union County in 2009 had a tornado report inside them.

Union County, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings110%0
Severe thunderstorm warnings10820%0
Flash flood warnings330%0

Each office's whole area, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS State College, PA: tornado warnings13377%580%22 min
NWS State College, PA: severe thunderstorm warnings1668648%18280%26 min
NWS State College, PA: flash flood warnings382339%4393%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.

IssuedProductOfficeLasted
Jan 5, 3:10 AM ESTWinter Storm WatchCTP19 hr
Jan 5, 10:11 PM ESTIce Storm WarningCTP39 hr
Jan 6, 5:17 PM ESTMesoscale DiscussionSPC4 hr
Jan 7, 12:10 AM ESTMesoscale DiscussionSPC4 hr
Jan 8, 3:30 PM ESTWinter Storm WatchCTP23 hr
Jan 9, 2:32 PM ESTWinter Storm WarningCTP30 hr
Jan 9, 2:32 PM ESTWinter Weather AdvisoryCTP37 hr
Jan 14, 4:25 AM ESTWinter Weather AdvisoryCTP38 hr
Jan 26, 3:30 AM ESTWinter Storm WatchCTP32 hr
Jan 27, 11:40 AM ESTWinter Storm WarningCTP31 hr
Jan 28, 12:31 AM ESTMesoscale DiscussionSPC5 hr
Jan 28, 7:53 AM ESTMesoscale DiscussionSPC5 hr
Feb 11, 3:09 PM ESTWind AdvisoryCTP32 hr
Feb 11, 8:00 PM ESTMesoscale DiscussionSPC60 min
Feb 11, 8:19 PM ESTSevere Thunderstorm WatchSPC3 hr
Feb 11, 8:41 PM ESTSevere Thunderstorm WarningCTP64 min
Feb 17, 2:45 PM ESTWinter Weather AdvisoryCTP34 hr
Feb 18, 12:38 PM ESTMesoscale DiscussionSPC3 hr
Mar 8, 3:29 PM EDTWind AdvisoryCTP24 hr
Mar 10, 3:48 PM EDTWind AdvisoryCTP28 hr
Mar 23, 4:48 AM EDTRed Flag WarningCTP15 hr
Mar 27, 3:55 AM EDTDense Fog AdvisoryCTP6 hr
Apr 3, 3:04 AM EDTHigh Wind WatchCTP9 hr
Apr 3, 11:47 AM EDTWind AdvisoryCTP28 hr
Apr 28, 10:43 AM EDTRed Flag WarningCTP9 hr
May 15, 2:39 AM EDTDense Fog AdvisoryCTP5 hr
May 16, 12:05 PM EDTMesoscale DiscussionSPC55 min
May 16, 1:00 PM EDTSevere Thunderstorm WatchSPC7 hr
May 16, 3:55 PM EDTMesoscale DiscussionSPC65 min
May 16, 6:29 PM EDTMesoscale DiscussionSPC2 hr
May 17, 3:20 AM EDTFrost AdvisoryCTP30 hr
May 18, 3:28 PM EDTFrost AdvisoryCTP17 hr
May 23, 12:49 PM EDTMesoscale DiscussionSPC56 min
May 24, 3:43 PM EDTSpecial Weather StatementCTP62 min
May 28, 8:02 PM EDTAreal Flood AdvisoryCTP3 hr
May 29, 1:58 AM EDTAreal Flood AdvisoryCTP3 hr
Jun 2, 2:54 AM EDTSpecial Weather StatementCTP66 min
Jun 2, 3:38 AM EDTSpecial Weather StatementCTP67 min
Jun 9, 11:48 AM EDTMesoscale DiscussionSPC87 min
Jun 9, 1:31 PM EDTSevere Thunderstorm WatchSPC6 hr
Jun 9, 3:40 PM EDTMesoscale DiscussionSPC65 min
Jun 11, 4:04 AM EDTFlash Flood WatchCTP23 hr
Jun 20, 7:15 AM EDTAreal Flood AdvisoryCTP3 hr
Jun 26, 2:19 PM EDTMesoscale DiscussionSPC56 min
Jun 26, 2:42 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 26, 5:34 PM EDTSpecial Weather StatementCTP26 min
Jun 26, 6:01 PM EDTSpecial Weather StatementCTP44 min
Jun 30, 10:06 AM EDTSpecial Weather StatementCTP54 min
Jul 3, 2:02 PM EDTSpecial Weather StatementCTP88 min
Jul 11, 10:31 AM EDTMesoscale DiscussionSPC59 min
Jul 11, 4:58 PM EDTSevere Thunderstorm WarningCTP62 min
Jul 11, 5:28 PM EDTTornado WarningCTP32 min
Jul 11, 7:06 PM EDTMesoscale DiscussionSPC114 min
Jul 11, 7:19 PM EDTSevere Thunderstorm WarningCTP71 min
Jul 11, 8:28 PM EDTSevere Thunderstorm WarningCTP62 min
Jul 11, 9:54 PM EDTAreal Flood AdvisoryCTP3 hr
Jul 11, 10:33 PM EDTFlash Flood WarningCTP4 hr
Jul 21, 1:56 PM EDTMesoscale DiscussionSPC64 min
Jul 23, 1:57 AM EDTSpecial Weather StatementCTP63 min
Jul 23, 6:06 PM EDTSpecial Weather StatementCTP54 min
Jul 23, 6:36 PM EDTFlash Flood WarningCTP3 hr
Jul 24, 2:20 PM EDTMesoscale DiscussionSPC115 min
Jul 24, 6:44 PM EDTSevere Thunderstorm WarningCTP61 min
Jul 25, 6:36 AM EDTDense Fog AdvisoryCTP3 hr
Jul 25, 3:05 PM EDTMesoscale DiscussionSPC55 min
Jul 25, 3:50 PM EDTSevere Thunderstorm WatchSPC5 hr
Jul 25, 5:14 PM EDTSevere Thunderstorm WarningCTP40 min
Jul 25, 7:43 PM EDTMesoscale DiscussionSPC62 min
Jul 26, 3:14 PM EDTMesoscale DiscussionSPC2 hr
Jul 31, 7:59 AM EDTAreal Flood AdvisoryCTP3 hr
Jul 31, 10:03 AM EDTFlash Flood WarningCTP6 hr
Jul 31, 10:20 AM EDTMesoscale DiscussionSPC85 min
Aug 1, 4:05 AM EDTDense Fog AdvisoryCTP5 hr
Aug 2, 2:29 AM EDTAreal Flood AdvisoryCTP3 hr
Aug 2, 5:08 AM EDTFlash Flood WatchCTP10 hr
Aug 9, 2:45 PM EDTMesoscale DiscussionSPC60 min
Aug 9, 3:09 PM EDTHeat AdvisoryCTP28 hr
Aug 9, 3:18 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 9, 3:47 PM EDTSevere Thunderstorm WarningCTP43 min
Aug 9, 4:25 PM EDTSevere Thunderstorm WarningCTP65 min
Aug 9, 7:11 PM EDTMesoscale DiscussionSPC2 hr
Aug 9, 10:44 PM EDTSevere Thunderstorm WatchSPC4 hr
Aug 9, 10:47 PM EDTMesoscale DiscussionSPC118 min
Aug 10, 5:09 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 10, 8:15 PM EDTMesoscale DiscussionSPC2 hr
Aug 11, 6:37 PM EDTSpecial Weather StatementCTP53 min
Aug 12, 12:36 PM EDTMesoscale DiscussionSPC84 min
Aug 12, 5:46 PM EDTSpecial Weather StatementCTP29 min
Aug 14, 4:04 AM EDTDense Fog AdvisoryCTP6 hr
Aug 15, 6:30 AM EDTDense Fog AdvisoryCTP4 hr
Aug 18, 2:32 PM EDTMesoscale DiscussionSPC88 min
Aug 18, 4:50 PM EDTSevere Thunderstorm WarningCTP55 min
Aug 19, 1:21 PM EDTMesoscale DiscussionSPC84 min
Aug 19, 3:47 PM EDTAreal Flood AdvisoryCTP3 hr
Sep 28, 9:56 AM EDTSpecial Weather StatementCTP64 min
Sep 28, 11:05 AM EDTSpecial Weather StatementCTP40 min
Oct 6, 2:59 PM EDTWind AdvisoryCTP29 hr
Oct 7, 5:39 AM EDTSpecial Weather StatementCTP51 min
Oct 10, 2:45 PM EDTFreeze WatchCTP24 hr
Oct 11, 2:51 PM EDTFrost AdvisoryCTP17 hr
Oct 13, 3:28 AM EDTFrost AdvisoryCTP30 hr
Oct 14, 3:35 PM EDTWinter Storm WatchCTP13 hr
Oct 15, 4:26 AM EDTWinter Weather AdvisoryCTP65 hr
Oct 24, 10:13 AM EDTAreal Flood AdvisoryCTP2 hr
Nov 26, 3:07 AM ESTDense Fog AdvisoryCTP6 hr
Dec 3, 3:31 AM ESTSevere Thunderstorm WarningCTP29 min
Dec 3, 3:58 AM ESTSpecial Weather StatementCTP47 min
Dec 5, 4:27 AM ESTWinter Weather AdvisoryCTP14 hr
Dec 8, 6:12 AM ESTWinter Weather AdvisoryCTP26 hr
Dec 8, 11:32 PM ESTMesoscale DiscussionSPC6 hr
Dec 9, 3:38 AM ESTWind AdvisoryCTP26 hr
Dec 12, 3:17 PM ESTFreezing Rain AdvisoryCTP25 hr
Dec 13, 5:16 AM ESTMesoscale DiscussionSPC4 hr
Dec 17, 10:08 PM ESTWinter Storm WatchCTP17 hr
Dec 18, 2:38 PM ESTWinter Storm WarningCTP32 hr
Dec 18, 2:38 PM ESTWinter Weather AdvisoryCTP32 hr
Dec 24, 2:05 PM ESTWinter Weather AdvisoryCTP29 hr
Dec 28, 2:33 PM ESTWind AdvisoryCTP28 hr
Dec 31, 6:40 PM ESTWinter Weather AdvisoryCTP6 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 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.