Alert archive / Pennsylvania / Union County

Weather alerts in Union County, Pennsylvania, 2023

124 weather alerts in 2023, 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 2023. Tap one for its archive.

Alerts
124
Warnings
28
Watches
19
Advisories
30
Busiest month
July34 alerts
Busiest day
August 7, 20238 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 2 tornado warnings covering Union County in 2023 had a tornado report inside them; 2 of 4 tornado reports fell inside a warning, on average 4 minutes after it went out.

Union County, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings2150%450%4 min
Severe thunderstorm warnings171229%757%3 min
Flash flood warnings20100%0

Each office's whole area, 2023

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS State College, PA: tornado warnings18572%1540%3 min
NWS State College, PA: severe thunderstorm warnings18613627%38183%19 min
NWS State College, PA: flash flood warnings8363%863%42 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 3, 2:21 AM ESTDense Fog AdvisoryCTP7 hr
Jan 3, 11:19 PM ESTDense Fog AdvisoryCTP12 hr
Jan 21, 2:13 PM ESTWinter Weather AdvisoryCTP43 hr
Jan 24, 4:16 AM ESTWinter Storm WatchCTP23 hr
Jan 24, 4:16 AM ESTWinter Weather AdvisoryCTP42 hr
Feb 3, 1:29 AM ESTSpecial Weather StatementCTP46 min
Feb 21, 3:45 PM ESTWinter Weather AdvisoryCTP28 hr
Feb 26, 3:45 PM ESTWinter Weather AdvisoryCTP43 hr
Mar 2, 1:39 PM ESTWinter Weather AdvisoryCTP43 hr
Mar 6, 3:44 AM ESTWinter Weather AdvisoryCTP25 hr
Mar 6, 6:51 PM ESTMesoscale DiscussionSPC4 hr
Mar 9, 10:33 AM ESTWinter Weather AdvisoryCTP40 hr
Mar 29, 8:36 PM EDTSpecial Weather StatementCTP54 min
Mar 31, 3:22 PM EDTWind AdvisoryCTP35 hr
Apr 1, 2:02 PM EDTMesoscale DiscussionSPC118 min
Apr 1, 2:27 PM EDTSevere Thunderstorm WatchSPC5 hr
Apr 5, 11:17 PM EDTSpecial Weather StatementCTP43 min
Apr 11, 3:49 PM EDTFire Weather WatchCTP17 hr
Apr 12, 8:54 AM EDTRed Flag WarningCTP11 hr
Apr 16, 7:41 AM EDTDense Fog AdvisoryCTP2 hr
Apr 22, 2:47 PM EDTMesoscale DiscussionSPC118 min
Apr 23, 12:52 PM EDTFrost AdvisoryCTP19 hr
Apr 24, 2:09 PM EDTFreeze WarningCTP19 hr
Apr 30, 8:31 AM EDTFlood WatchCTP11 hr
May 16, 3:09 PM EDTFreeze WatchCTP20 hr
May 17, 11:05 AM EDTFreeze WarningCTP21 hr
Jun 3, 1:27 PM EDTMesoscale DiscussionSPC2 hr
Jun 3, 3:22 PM EDTSpecial Weather StatementCTP23 min
Jun 3, 3:29 PM EDTSevere Thunderstorm WarningCTP46 min
Jun 3, 3:58 PM EDTSevere Thunderstorm WarningCTP47 min
Jun 3, 4:45 PM EDTSevere Thunderstorm WarningCTP45 min
Jun 3, 5:23 PM EDTSevere Thunderstorm WarningCTP37 min
Jun 5, 3:30 PM EDTFire Weather WatchCTP17 hr
Jun 6, 8:26 AM EDTRed Flag WarningCTP12 hr
Jun 6, 1:10 PM EDTMesoscale DiscussionSPC2 hr
Jun 26, 12:36 PM EDTMesoscale DiscussionSPC2 hr
Jun 26, 1:11 PM EDTSevere Thunderstorm WatchSPC11 hr
Jun 26, 6:25 PM EDTSpecial Weather StatementCTP35 min
Jun 26, 6:34 PM EDTSevere Thunderstorm WarningCTP41 min
Jun 26, 7:10 PM EDTSpecial Weather StatementCTP35 min
Jun 26, 8:03 PM EDTMesoscale DiscussionSPC87 min
Jun 26, 8:47 PM EDTSpecial Weather StatementCTP28 min
Jul 1, 1:54 PM EDTMesoscale DiscussionSPC2 hr
Jul 2, 3:24 PM EDTMesoscale DiscussionSPC96 min
Jul 2, 4:21 PM EDTTornado Warning Tornado observedCTP24 min
Jul 2, 4:46 PM EDTTornado WarningCTP29 min
Jul 6, 8:04 PM EDTSevere Thunderstorm WarningCTP41 min
Jul 6, 8:50 PM EDTSpecial Weather StatementCTP40 min
Jul 7, 3:05 PM EDTAreal Flood AdvisoryCTP2 hr
Jul 7, 3:40 PM EDTFlash Flood WarningCTP2 hr
Jul 8, 3:12 PM EDTFlood WatchCTP26 hr
Jul 9, 4:19 AM EDTSpecial Weather StatementCTP41 min
Jul 9, 12:47 PM EDTSpecial Weather StatementCTP28 min
Jul 12, 4:35 PM EDTSpecial Weather StatementCTP25 min
Jul 13, 2:36 PM EDTMesoscale DiscussionSPC2 hr
Jul 13, 11:59 PM EDTSevere Thunderstorm WarningCTP46 min
Jul 14, 3:48 PM EDTSevere Thunderstorm WarningCTP42 min
Jul 14, 4:21 PM EDTSevere Thunderstorm WarningCTP39 min
Jul 14, 5:04 PM EDTSevere Thunderstorm WarningCTP41 min
Jul 15, 5:50 AM EDTDense Fog AdvisoryCTP3 hr
Jul 15, 6:44 PM EDTFlood WatchCTP23 hr
Jul 15, 10:21 PM EDTAreal Flood AdvisoryCTP3 hr
Jul 15, 10:53 PM EDTFlash Flood WarningCTP3 hr
Jul 16, 1:38 AM EDTAreal Flood WarningCTP6 hr
Jul 17, 6:34 PM EDTSpecial Weather StatementCTP56 min
Jul 19, 4:48 PM EDTMesoscale DiscussionSPC87 min
Jul 20, 6:19 PM EDTSevere Thunderstorm WatchSPC9 hr
Jul 20, 10:07 PM EDTMesoscale DiscussionSPC113 min
Jul 20, 10:37 PM EDTSpecial Weather StatementCTP53 min
Jul 20, 10:58 PM EDTSpecial Weather StatementCTP47 min
Jul 20, 11:12 PM EDTSevere Thunderstorm WarningCTP48 min
Jul 24, 3:14 PM EDTSevere Thunderstorm WarningCTP46 min
Jul 24, 8:46 PM EDTSpecial Weather StatementCTP44 min
Jul 26, 5:36 AM EDTHeat AdvisoryCTP62 hr
Jul 27, 11:40 AM EDTMesoscale DiscussionSPC2 hr
Jul 27, 4:46 PM EDTMesoscale DiscussionSPC89 min
Aug 4, 11:21 AM EDTMesoscale DiscussionSPC114 min
Aug 4, 12:10 PM EDTSevere Thunderstorm WatchSPC10 hr
Aug 4, 2:49 PM EDTMesoscale DiscussionSPC116 min
Aug 4, 3:11 PM EDTSevere Thunderstorm WarningCTP49 min
Aug 4, 3:16 PM EDTSevere Thunderstorm WarningCTP59 min
Aug 4, 5:23 PM EDTSpecial Weather StatementCTP52 min
Aug 4, 6:13 PM EDTMesoscale DiscussionSPC2 hr
Aug 5, 5:57 AM EDTDense Fog AdvisoryCTP3 hr
Aug 7, 1:20 PM EDTTornado WatchSPC11 hr
Aug 7, 3:02 PM EDTSevere Thunderstorm WarningCTP43 min
Aug 7, 3:17 PM EDTMesoscale DiscussionSPC88 min
Aug 7, 3:45 PM EDTSevere Thunderstorm WarningCTP45 min
Aug 7, 3:55 PM EDTAreal Flood AdvisoryCTP2 hr
Aug 7, 4:06 PM EDTSevere Thunderstorm WarningCTP39 min
Aug 7, 4:34 PM EDTAreal Flood AdvisoryCTP3 hr
Aug 7, 4:40 PM EDTMesoscale DiscussionSPC95 min
Aug 12, 12:50 PM EDTTornado WatchSPC8 hr
Aug 12, 4:04 PM EDTMesoscale DiscussionSPC116 min
Aug 17, 10:37 PM EDTAreal Flood AdvisoryCTP3 hr
Aug 17, 11:04 PM EDTMesoscale DiscussionSPC3 hr
Aug 18, 1:41 AM EDTAreal Flood AdvisoryCTP3 hr
Aug 18, 6:23 AM EDTAreal Flood AdvisoryCTP4 hr
Aug 29, 1:57 PM EDTFlood WatchCTP14 hr
Aug 30, 2:25 AM EDTAreal Flood AdvisoryCTP2 hr
Sep 7, 11:58 AM EDTMesoscale DiscussionSPC3 hr
Sep 7, 1:14 PM EDTSevere Thunderstorm WatchSPC8 hr
Sep 7, 3:06 PM EDTMesoscale DiscussionSPC84 min
Sep 8, 2:46 PM EDTMesoscale DiscussionSPC119 min
Sep 8, 3:11 PM EDTSevere Thunderstorm WatchSPC8 hr
Sep 9, 2:08 PM EDTMesoscale DiscussionSPC3 hr
Sep 9, 4:23 PM EDTSevere Thunderstorm WatchSPC5 hr
Sep 9, 6:06 PM EDTMesoscale DiscussionSPC114 min
Sep 9, 8:08 PM EDTMesoscale DiscussionSPC2 hr
Oct 1, 2:31 AM EDTDense Fog AdvisoryCTP7 hr
Oct 3, 3:46 AM EDTDense Fog AdvisoryCTP6 hr
Oct 4, 2:53 AM EDTDense Fog AdvisoryCTP7 hr
Oct 23, 1:30 PM EDTFrost AdvisoryCTP20 hr
Oct 30, 3:02 AM EDTFrost AdvisoryCTP30 hr
Oct 31, 3:36 AM EDTFreeze WatchCTP23 hr
Nov 1, 2:18 AM EDTFreeze WarningCTP32 hr
Dec 2, 8:05 AM ESTDense Fog AdvisoryCTP115 min
Dec 3, 6:16 PM ESTSpecial Weather StatementCTP29 min
Dec 3, 6:37 PM ESTSpecial Weather StatementCTP23 min
Dec 7, 6:22 AM ESTSpecial Weather StatementCTP53 min
Dec 7, 7:20 AM ESTSpecial Weather StatementCTP55 min
Dec 16, 1:39 PM ESTFlood WatchCTP46 hr
Dec 18, 12:37 AM ESTAreal Flood AdvisoryCTP6 hr
Dec 19, 4:36 AM ESTRiver Flood WarningCTP23 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 archive20222024

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.