Alert archive / Pennsylvania / Lancaster County

Weather alerts in Lancaster County, Pennsylvania, 2010

236 weather alerts in 2010, from the National Weather Service and the Storm Prediction Center. An alert counts here when it covered this county.

Lancaster County and its neighbors

Each county as a circle sized by its count in 2010. Tap one for its archive.

Alerts
236
Warnings
78
Watches
34
Advisories
40
Busiest month
June43 alerts
Busiest day
September 30, 201014 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 3 tornado warnings covering Lancaster County in 2010 had a tornado report inside them; 0 of 1 tornado reports fell inside a warning.

Lancaster County, 2010

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings30100%10%
Severe thunderstorm warnings473428%4980%26 min
Flash flood warnings7529%4100%67 min

Each office's whole area, 2010

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS State College, PA: tornado warnings17288%650%25 min
NWS State College, PA: severe thunderstorm warnings21313138%31985%27 min
NWS State College, PA: flash flood warnings22959%2471%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.

IssuedProductOfficeLasted
Jan 2, 3:16 PM ESTWind AdvisoryCTP28 hr
Jan 4, 2:24 PM ESTSpecial Weather StatementCTP21 min
Jan 16, 2:48 PM ESTFreezing Rain AdvisoryCTP14 hr
Jan 23, 2:56 PM ESTFlood WatchCTP48 hr
Jan 24, 9:23 PM ESTWind AdvisoryCTP15 hr
Jan 25, 6:20 AM ESTAreal Flood WarningCTP6 hr
Jan 25, 8:48 AM ESTSpecial Weather StatementCTP87 min
Jan 25, 12:17 PM ESTAreal Flood WarningCTP14 hr
Jan 25, 9:26 PM ESTRiver Flood WarningCTP36 hr
Jan 25, 9:26 PM ESTRiver Flood WarningCTP48 hr
Jan 30, 4:30 PM ESTSpecial Weather StatementCTP75 min
Feb 2, 2:20 PM ESTWinter Weather AdvisoryCTP13 hr
Feb 4, 3:20 AM ESTWinter Storm WatchCTP12 hr
Feb 4, 3:09 PM ESTWinter Storm WarningCTP46 hr
Feb 5, 6:58 PM ESTMesoscale DiscussionSPC4 hr
Feb 7, 9:31 PM ESTWinter Storm WatchCTP30 hr
Feb 8, 3:56 PM ESTWinter Storm WarningCTP54 hr
Feb 10, 7:27 AM ESTMesoscale DiscussionSPC5 hr
Feb 10, 9:41 AM ESTBlizzard WarningCTP15 hr
Feb 10, 12:20 PM ESTMesoscale DiscussionSPC4 hr
Feb 15, 4:05 AM ESTWinter Weather AdvisoryCTP31 hr
Feb 23, 8:21 PM ESTWinter Storm WatchCTP29 hr
Feb 24, 3:15 PM ESTWinter Weather AdvisoryCTP48 hr
Feb 25, 10:33 AM ESTHigh Wind WatchCTP4 hr
Feb 25, 2:47 PM ESTWind AdvisoryCTP24 hr
Mar 10, 4:24 AM ESTFlood WatchCTP4 days
Mar 13, 10:09 AM ESTWind AdvisoryCTP12 hr
Mar 13, 4:07 PM ESTAreal Flood WarningCTP8 hr
Mar 28, 2:19 PM EDTFlood WatchCTP12 hr
Apr 7, 3:43 AM EDTRed Flag WarningCTP15 hr
Apr 8, 4:48 PM EDTSevere Thunderstorm WatchSPC5 hr
Apr 13, 2:52 PM EDTFrost AdvisoryCTP17 hr
Apr 14, 2:00 AM EDTDense Fog AdvisoryCTP8 hr
Apr 16, 1:28 PM EDTSevere Thunderstorm WatchSPC7 hr
Apr 16, 6:06 PM EDTSevere Thunderstorm WarningCTP69 min
Apr 16, 6:14 PM EDTMesoscale DiscussionSPC61 min
Apr 16, 6:49 PM EDTSevere Thunderstorm WarningCTP56 min
Apr 19, 2:33 PM EDTFrost AdvisoryCTP17 hr
Apr 22, 4:33 AM EDTDense Fog AdvisoryCTP4 hr
Apr 27, 2:23 PM EDTFrost AdvisoryCTP15 hr
Apr 28, 2:36 PM EDTFire Weather WatchCTP15 hr
Apr 29, 5:22 AM EDTRed Flag WarningCTP15 hr
Apr 30, 8:09 PM EDTAreal Flood WarningCTP31 days
May 2, 5:58 PM EDTSevere Thunderstorm WatchSPC5 hr
May 2, 8:27 PM EDTMesoscale DiscussionSPC63 min
May 2, 10:47 PM EDTSpecial Weather StatementCTP88 min
May 2, 11:05 PM EDTSevere Thunderstorm WarningCTP25 min
May 2, 11:32 PM EDTSpecial Weather StatementCTP28 min
May 3, 12:42 AM EDTFlash Flood WatchCTP4 hr
May 3, 6:14 AM EDTAreal Flood AdvisoryCTP3 hr
May 7, 3:41 PM EDTWind AdvisoryCTP31 hr
May 9, 12:48 PM EDTFrost AdvisoryCTP19 hr
May 14, 2:29 PM EDTSevere Thunderstorm WatchSPC7 hr
May 14, 5:41 PM EDTSevere Thunderstorm WarningCTP64 min
May 14, 6:00 PM EDTSevere Thunderstorm WarningCTP75 min
May 14, 6:35 PM EDTMesoscale DiscussionSPC55 min
May 14, 7:26 PM EDTAreal Flood AdvisoryCTP2 hr
May 27, 11:28 AM EDTMesoscale DiscussionSPC92 min
May 27, 1:23 PM EDTSevere Thunderstorm WatchSPC8 hr
May 27, 4:13 PM EDTMesoscale DiscussionSPC62 min
May 27, 8:08 PM EDTMesoscale DiscussionSPC97 min
May 27, 9:24 PM EDTSevere Thunderstorm WarningCTP36 min
May 27, 10:03 PM EDTSevere Thunderstorm WarningCTP27 min
May 27, 10:34 PM EDTSevere Thunderstorm WarningCTP26 min
May 27, 11:54 PM EDTSpecial Weather StatementCTP66 min
May 31, 2:59 PM EDTSpecial Weather StatementCTP46 min
May 31, 4:07 PM EDTSevere Thunderstorm WarningCTP53 min
May 31, 4:35 PM EDTAreal Flood AdvisoryCTP3 hr
May 31, 4:39 PM EDTSevere Thunderstorm WarningCTP66 min
May 31, 4:47 PM EDTAreal Flood AdvisoryCTP3 hr
May 31, 4:58 PM EDTSevere Thunderstorm WarningCTP62 min
May 31, 5:02 PM EDTSevere Thunderstorm WarningCTP58 min
May 31, 5:11 PM EDTFlash Flood WarningCTP3 hr
May 31, 5:44 PM EDTSevere Thunderstorm WarningCTP61 min
May 31, 5:48 PM EDTFlash Flood WarningCTP3 hr
May 31, 5:59 PM EDTSevere Thunderstorm WarningCTP76 min
May 31, 6:46 PM EDTSevere Thunderstorm WarningCTP59 min
Jun 3, 11:27 AM EDTMesoscale DiscussionSPC93 min
Jun 3, 1:32 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 3, 3:36 PM EDTMesoscale DiscussionSPC54 min
Jun 3, 6:28 PM EDTMesoscale DiscussionSPC62 min
Jun 3, 7:42 PM EDTAreal Flood AdvisoryCTP3 hr
Jun 3, 7:49 PM EDTSevere Thunderstorm WarningCTP56 min
Jun 3, 8:18 PM EDTSpecial Weather StatementCTP57 min
Jun 3, 8:32 PM EDTSevere Thunderstorm WarningCTP58 min
Jun 4, 1:09 PM EDTMesoscale DiscussionSPC66 min
Jun 4, 2:39 PM EDTSevere Thunderstorm WatchSPC8 hr
Jun 4, 2:50 PM EDTSpecial Weather StatementCTP25 min
Jun 4, 3:17 PM EDTSevere Thunderstorm WarningCTP42 min
Jun 4, 4:24 PM EDTMesoscale DiscussionSPC66 min
Jun 4, 5:35 PM EDTSpecial Weather StatementCTP25 min
Jun 4, 6:02 PM EDTSpecial Weather StatementCTP13 min
Jun 4, 6:13 PM EDTSpecial Weather StatementCTP62 min
Jun 4, 7:03 PM EDTMesoscale DiscussionSPC57 min
Jun 4, 9:52 PM EDTSevere Thunderstorm WarningCTP53 min
Jun 4, 10:32 PM EDTSpecial Weather StatementCTP58 min
Jun 6, 10:25 AM EDTMesoscale DiscussionSPC65 min
Jun 6, 11:08 AM EDTTornado WatchSPC8 hr
Jun 6, 2:44 PM EDTSpecial Weather StatementCTP16 min
Jun 10, 12:26 AM EDTDense Fog AdvisoryCTP7 hr
Jun 13, 12:58 PM EDTMesoscale DiscussionSPC2 hr
Jun 16, 10:28 PM EDTSpecial Weather StatementCTP47 min
Jun 16, 11:11 PM EDTSpecial Weather StatementCTP49 min
Jun 22, 11:35 AM EDTMesoscale DiscussionSPC25 min
Jun 22, 3:48 PM EDTMesoscale DiscussionSPC27 min
Jun 22, 4:19 PM EDTSpecial Weather StatementCTP56 min
Jun 22, 4:32 PM EDTSevere Thunderstorm WarningCTP73 min
Jun 22, 4:49 PM EDTSevere Thunderstorm WarningCTP71 min
Jun 22, 5:18 PM EDTTornado WarningCTP42 min
Jun 22, 7:06 PM EDTSpecial Weather StatementCTP9 min
Jun 24, 12:16 PM EDTMesoscale DiscussionSPC89 min
Jun 24, 12:28 PM EDTSevere Thunderstorm WatchSPC8 hr
Jun 24, 1:29 PM EDTSevere Thunderstorm WarningCTP61 min
Jun 24, 2:02 PM EDTSevere Thunderstorm WarningCTP58 min
Jun 24, 2:43 PM EDTSevere Thunderstorm WarningCTP62 min
Jun 24, 3:07 PM EDTMesoscale DiscussionSPC53 min
Jun 27, 8:31 PM EDTSpecial Weather StatementCTP44 min
Jun 28, 12:26 PM EDTMesoscale DiscussionSPC2 hr
Jun 28, 1:12 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 28, 3:53 PM EDTMesoscale DiscussionSPC2 hr
Jul 5, 12:46 PM EDTHeat AdvisoryCTP55 hr
Jul 8, 3:58 PM EDTSpecial Weather StatementCTP32 min
Jul 12, 4:59 PM EDTSpecial Weather StatementCTP31 min
Jul 12, 5:18 PM EDTSevere Thunderstorm WarningCTP42 min
Jul 12, 7:40 PM EDTSpecial Weather StatementCTP35 min
Jul 12, 7:53 PM EDTSpecial Weather StatementCTP37 min
Jul 13, 3:36 AM EDTAreal Flood AdvisoryCTP6 hr
Jul 13, 9:55 PM EDTSpecial Weather StatementCTP110 min
Jul 14, 1:04 AM EDTAreal Flood AdvisoryCTP3 hr
Jul 14, 10:10 AM EDTAreal Flood AdvisoryCTP3 hr
Jul 14, 10:41 AM EDTFlash Flood WarningCTP4 hr
Jul 14, 1:58 PM EDTAreal Flood WarningCTP4 hr
Jul 19, 5:05 AM EDTSpecial Weather StatementCTP55 min
Jul 19, 1:17 PM EDTMesoscale DiscussionSPC58 min
Jul 19, 4:42 PM EDTSpecial Weather StatementCTP33 min
Jul 19, 5:24 PM EDTSpecial Weather StatementCTP36 min
Jul 19, 5:37 PM EDTSevere Thunderstorm WarningCTP23 min
Jul 19, 8:39 PM EDTSpecial Weather StatementCTP21 min
Jul 21, 11:27 AM EDTSevere Thunderstorm WatchSPC9 hr
Jul 21, 12:38 PM EDTMesoscale DiscussionSPC67 min
Jul 21, 3:41 PM EDTMesoscale DiscussionSPC64 min
Jul 21, 7:00 PM EDTMesoscale DiscussionSPC90 min
Jul 21, 7:35 PM EDTSevere Thunderstorm WatchSPC5 hr
Jul 21, 10:41 PM EDTSpecial Weather StatementCTP34 min
Jul 23, 6:13 AM EDTExcessive Heat WatchCTP10 hr
Jul 23, 6:13 AM EDTHeat AdvisoryCTP15 hr
Jul 23, 4:18 PM EDTExcessive Heat WarningCTP29 hr
Jul 23, 6:23 PM EDTMesoscale DiscussionSPC67 min
Jul 25, 10:48 AM EDTMesoscale DiscussionSPC27 min
Jul 25, 11:29 AM EDTSevere Thunderstorm WatchSPC8 hr
Jul 25, 12:50 PM EDTMesoscale DiscussionSPC55 min
Jul 25, 1:03 PM EDTTornado WarningCTP27 min
Jul 25, 1:15 PM EDTSevere Thunderstorm WarningCTP60 min
Jul 25, 1:38 PM EDTSevere Thunderstorm WarningCTP52 min
Jul 25, 2:33 PM EDTSevere Thunderstorm WarningCTP42 min
Jul 25, 2:38 PM EDTAreal Flood AdvisoryCTP3 hr
Aug 4, 11:09 AM EDTHeat AdvisoryCTP9 hr
Aug 4, 3:10 PM EDTHeat AdvisoryCTP28 hr
Aug 4, 5:52 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 4, 7:48 PM EDTMesoscale DiscussionSPC87 min
Aug 4, 8:39 PM EDTSevere Thunderstorm WarningCTP66 min
Aug 4, 9:25 PM EDTSevere Thunderstorm WarningCTP65 min
Aug 4, 9:50 PM EDTSevere Thunderstorm WarningCTP55 min
Aug 12, 3:15 PM EDTAreal Flood AdvisoryCTP3 hr
Aug 12, 3:48 PM EDTFlash Flood WarningCTP4 hr
Aug 16, 12:05 PM EDTSevere Thunderstorm WatchSPC9 hr
Aug 16, 2:17 PM EDTMesoscale DiscussionSPC88 min
Aug 16, 4:12 PM EDTSevere Thunderstorm WarningCTP63 min
Aug 16, 4:20 PM EDTSevere Thunderstorm WarningCTP55 min
Aug 16, 5:05 PM EDTTornado WarningCTP25 min
Aug 16, 5:31 PM EDTSpecial Weather StatementCTP14 min
Aug 16, 5:37 PM EDTSevere Thunderstorm WarningCTP63 min
Aug 16, 7:16 PM EDTMesoscale DiscussionSPC59 min
Aug 16, 8:38 PM EDTAreal Flood AdvisoryCTP3 hr
Aug 16, 9:08 PM EDTSevere Thunderstorm WarningCTP67 min
Aug 16, 9:27 PM EDTFlash Flood WarningCTP3 hr
Aug 16, 10:12 PM EDTSevere Thunderstorm WarningCTP63 min
Sep 7, 9:59 PM EDTFire Weather WatchCTP12 hr
Sep 8, 10:03 AM EDTRed Flag WarningCTP9 hr
Sep 22, 2:34 PM EDTSevere Thunderstorm WatchSPC6 hr
Sep 22, 3:19 PM EDTSevere Thunderstorm WarningCTP56 min
Sep 22, 3:57 PM EDTSevere Thunderstorm WarningCTP78 min
Sep 22, 4:15 PM EDTSevere Thunderstorm WarningCTP60 min
Sep 22, 4:46 PM EDTMesoscale DiscussionSPC59 min
Sep 22, 5:02 PM EDTSevere Thunderstorm WarningCTP58 min
Sep 22, 6:17 PM EDTSevere Thunderstorm WarningCTP58 min
Sep 22, 6:47 PM EDTSevere Thunderstorm WarningCTP73 min
Sep 22, 7:14 PM EDTMesoscale DiscussionSPC61 min
Sep 22, 7:45 PM EDTSevere Thunderstorm WarningCTP60 min
Sep 27, 1:03 PM EDTMesoscale DiscussionSPC87 min
Sep 27, 3:03 PM EDTAreal Flood AdvisoryCTP4 hr
Sep 27, 3:29 PM EDTSpecial Weather StatementCTP31 min
Sep 28, 8:00 AM EDTMesoscale DiscussionSPC2 hr
Sep 28, 9:15 AM EDTSpecial Weather StatementCTP30 min
Sep 28, 10:18 AM EDTSpecial Weather StatementCTP27 min
Sep 28, 10:20 AM EDTSpecial Weather StatementCTP25 min
Sep 29, 3:16 AM EDTFlood WatchCTP50 hr
Sep 30, 7:23 AM EDTSpecial Weather StatementCTP37 min
Sep 30, 7:50 AM EDTAreal Flood AdvisoryCTP3 hr
Sep 30, 8:28 AM EDTAreal Flood WarningCTP12 hr
Sep 30, 8:58 AM EDTSevere Thunderstorm WarningCTP62 min
Sep 30, 10:05 AM EDTSpecial Weather StatementCTP55 min
Sep 30, 10:38 AM EDTSevere Thunderstorm WarningCTP37 min
Sep 30, 10:49 AM EDTMesoscale DiscussionSPC116 min
Sep 30, 11:07 AM EDTRiver Flood WarningCTP34 hr
Sep 30, 12:39 PM EDTTornado WatchSPC6 hr
Sep 30, 12:45 PM EDTSpecial Weather StatementCTP30 min
Sep 30, 1:27 PM EDTSpecial Weather StatementCTP33 min
Sep 30, 1:42 PM EDTFlash Flood WarningCTP6 hr
Sep 30, 3:16 PM EDTMesoscale DiscussionSPC119 min
Sep 30, 7:24 PM EDTFlash Flood WarningCTP6 hr
Oct 1, 1:13 AM EDTAreal Flood WarningCTP8 hr
Oct 1, 9:10 AM EDTAreal Flood WarningCTP6 hr
Oct 1, 3:14 PM EDTAreal Flood WarningCTP6 hr
Oct 11, 3:38 PM EDTSevere Thunderstorm WatchSPC6 hr
Oct 12, 3:05 AM EDTSpecial Weather StatementCTP40 min
Oct 22, 1:36 PM EDTFrost AdvisoryCTP19 hr
Oct 29, 3:29 AM EDTFreeze WatchCTP11 hr
Oct 29, 2:28 PM EDTFreeze WarningCTP19 hr
Nov 16, 2:25 PM ESTWind AdvisoryCTP28 hr
Nov 17, 12:06 AM ESTSevere Thunderstorm WatchSPC4 hr
Nov 17, 12:50 AM ESTAreal Flood AdvisoryCTP3 hr
Nov 17, 1:22 AM ESTSpecial Weather StatementCTP38 min
Nov 17, 1:45 AM ESTSevere Thunderstorm WarningCTP46 min
Nov 29, 1:23 PM ESTFlood WatchCTP49 hr
Dec 1, 5:01 AM ESTAreal Flood AdvisoryCTP6 hr
Dec 1, 6:55 AM ESTMesoscale DiscussionSPC65 min
Dec 1, 9:59 AM ESTSpecial Weather StatementCTP31 min
Dec 1, 11:36 AM ESTAreal Flood AdvisoryCTP4 hr
Dec 10, 12:33 PM ESTSpecial Weather StatementCTP2 hr
Dec 11, 6:58 PM ESTSpecial Weather StatementCTP2 hr
Dec 11, 7:16 PM ESTFreezing Rain AdvisoryCTP3 hr
Dec 13, 8:21 AM ESTSpecial Weather StatementCTP54 min
Dec 25, 12:01 PM ESTWinter Storm WatchCTP17 hr
Dec 26, 4:31 AM ESTWinter Storm WarningCTP22 hr
Dec 27, 3:32 AM ESTWind AdvisoryCTP17 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 archive20092011

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.