Alert archive / Pennsylvania / Lehigh County

Weather alerts in Lehigh County, Pennsylvania, 2009

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

Lehigh County and its neighbors

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

Alerts
121
Warnings
31
Watches
25
Advisories
34
Busiest month
July29 alerts
Busiest day
July 29, 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.

Lehigh County, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
Tornado warnings00
Severe thunderstorm warnings161319%875%39 min
Flash flood warnings5180%20%

Each office's whole area, 2009

WarningsWith a reportFalse alarm ratioReportsInside a warningMean lead time
NWS Philadelphia/Mount Holly: tornado warnings13192%250%38 min
NWS Philadelphia/Mount Holly: severe thunderstorm warnings23511352%26082%26 min
NWS Philadelphia/Mount Holly: flash flood warnings672070%6962%85 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, 3:46 AM ESTWinter Storm WatchPHI25 hr
Jan 6, 4:39 AM ESTWinter Storm WarningPHI16 hr
Jan 6, 8:55 PM ESTIce Storm WarningPHI19 hr
Jan 7, 12:10 AM ESTMesoscale DiscussionSPC4 hr
Jan 9, 4:19 AM ESTWinter Storm WatchPHI11 hr
Jan 9, 3:27 PM ESTWinter Storm WarningPHI37 hr
Jan 9, 3:27 PM ESTWinter Weather AdvisoryPHI37 hr
Jan 10, 7:58 PM ESTMesoscale DiscussionSPC4 hr
Jan 26, 2:42 AM ESTWinter Storm WatchPHI25 hr
Jan 27, 3:18 AM ESTWinter Storm WarningPHI40 hr
Jan 28, 12:31 AM ESTMesoscale DiscussionSPC5 hr
Jan 28, 7:53 AM ESTMesoscale DiscussionSPC5 hr
Feb 2, 2:53 PM ESTWinter Weather AdvisoryPHI37 hr
Feb 11, 2:50 PM ESTWind AdvisoryPHI13 hr
Feb 12, 3:30 AM ESTHigh Wind WarningPHI16 hr
Feb 12, 6:51 PM ESTWind AdvisoryPHI5 hr
Mar 1, 3:30 AM ESTWinter Storm WarningPHI37 hr
Mar 2, 3:45 AM ESTWinter Weather AdvisoryPHI12 hr
Mar 2, 5:38 AM ESTMesoscale DiscussionSPC3 hr
Mar 23, 4:23 AM EDTRed Flag WarningPHI19 hr
Mar 29, 5:11 PM EDTSevere Thunderstorm WarningPHI64 min
Mar 29, 5:27 PM EDTSevere Thunderstorm WarningPHI63 min
Mar 29, 5:55 PM EDTSevere Thunderstorm WarningPHI50 min
Apr 2, 5:13 AM EDTDense Fog AdvisoryPHI4 hr
Apr 3, 3:08 PM EDTWind AdvisoryPHI29 hr
Apr 28, 10:34 AM EDTRed Flag WarningPHI9 hr
May 16, 6:29 PM EDTMesoscale DiscussionSPC2 hr
May 16, 9:53 PM EDTAreal Flood AdvisoryPHI95 min
May 18, 4:27 AM EDTFrost AdvisoryPHI28 hr
May 23, 4:34 PM EDTAreal Flood AdvisoryPHI85 min
May 24, 11:49 AM EDTMesoscale DiscussionSPC116 min
May 24, 7:11 PM EDTMesoscale DiscussionSPC64 min
Jun 9, 6:01 AM EDTMesoscale DiscussionSPC59 min
Jun 9, 1:31 PM EDTSevere Thunderstorm WatchSPC6 hr
Jun 11, 3:15 PM EDTFlash Flood WatchPHI13 hr
Jun 13, 2:33 PM EDTFlash Flood WarningPHI112 min
Jun 15, 3:16 PM EDTSevere Thunderstorm WarningPHI59 min
Jun 15, 4:15 PM EDTSevere Thunderstorm WarningPHI60 min
Jun 16, 12:42 AM EDTAreal Flood AdvisoryPHI3 hr
Jun 26, 2:19 PM EDTMesoscale DiscussionSPC56 min
Jun 26, 2:42 PM EDTSevere Thunderstorm WatchSPC7 hr
Jun 26, 6:16 PM EDTSevere Thunderstorm WarningPHI59 min
Jun 26, 7:33 PM EDTMesoscale DiscussionSPC57 min
Jun 30, 11:37 AM EDTSevere Thunderstorm WatchSPC7 hr
Jun 30, 2:18 PM EDTMesoscale DiscussionSPC57 min
Jul 1, 12:03 PM EDTMesoscale DiscussionSPC87 min
Jul 1, 11:55 PM EDTAreal Flood AdvisoryPHI3 hr
Jul 7, 11:05 AM EDTSevere Thunderstorm WatchSPC8 hr
Jul 7, 2:00 PM EDTMesoscale DiscussionSPC90 min
Jul 7, 2:29 PM EDTSevere Thunderstorm WarningPHI61 min
Jul 11, 9:05 PM EDTAreal Flood AdvisoryPHI4 hr
Jul 16, 4:04 PM EDTMesoscale DiscussionSPC86 min
Jul 17, 7:07 PM EDTSevere Thunderstorm WarningPHI53 min
Jul 17, 9:17 PM EDTAreal Flood AdvisoryPHI3 hr
Jul 24, 2:20 PM EDTMesoscale DiscussionSPC115 min
Jul 24, 3:34 PM EDTMesoscale DiscussionSPC86 min
Jul 26, 3:07 AM EDTFlash Flood WatchPHI20 hr
Jul 26, 3:14 PM EDTMesoscale DiscussionSPC2 hr
Jul 26, 3:51 PM EDTSevere Thunderstorm WatchSPC7 hr
Jul 26, 4:06 PM EDTSevere Thunderstorm WarningPHI54 min
Jul 26, 6:37 PM EDTMesoscale DiscussionSPC113 min
Jul 26, 8:26 PM EDTSevere Thunderstorm WarningPHI37 min
Jul 29, 10:15 AM EDTFlash Flood WatchPHI17 hr
Jul 29, 12:12 PM EDTSevere Thunderstorm WarningPHI78 min
Jul 29, 12:22 PM EDTMesoscale DiscussionSPC23 min
Jul 29, 12:49 PM EDTSevere Thunderstorm WatchSPC8 hr
Jul 29, 2:22 PM EDTMesoscale DiscussionSPC23 min
Jul 29, 5:05 PM EDTMesoscale DiscussionSPC55 min
Jul 29, 5:28 PM EDTSevere Thunderstorm WarningPHI40 min
Jul 29, 7:14 PM EDTMesoscale DiscussionSPC61 min
Jul 29, 9:42 PM EDTAreal Flood AdvisoryPHI3 hr
Jul 30, 3:30 PM EDTFlash Flood WatchPHI27 hr
Jul 31, 10:20 AM EDTMesoscale DiscussionSPC85 min
Jul 31, 1:18 PM EDTSevere Thunderstorm WatchSPC7 hr
Aug 2, 2:19 AM EDTFlash Flood WatchPHI13 hr
Aug 2, 9:06 AM EDTFlash Flood WarningPHI4 hr
Aug 2, 11:14 AM EDTSevere Thunderstorm WarningPHI61 min
Aug 2, 4:06 PM EDTAreal Flood AdvisoryPHI4 hr
Aug 9, 11:57 AM EDTFlash Flood WatchPHI11 hr
Aug 9, 1:56 PM EDTHeat AdvisoryPHI30 hr
Aug 9, 2:45 PM EDTMesoscale DiscussionSPC60 min
Aug 9, 3:18 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 9, 4:30 PM EDTSevere Thunderstorm WarningPHI90 min
Aug 9, 7:11 PM EDTMesoscale DiscussionSPC2 hr
Aug 10, 5:09 PM EDTSevere Thunderstorm WatchSPC5 hr
Aug 10, 8:15 PM EDTMesoscale DiscussionSPC2 hr
Aug 12, 10:33 PM EDTFlash Flood WarningPHI4 hr
Aug 12, 11:23 PM EDTFlash Flood WarningPHI7 hr
Aug 13, 3:36 AM EDTFlood WatchPHI36 min
Aug 13, 4:12 AM EDTFlash Flood WatchPHI15 hr
Aug 19, 1:21 PM EDTMesoscale DiscussionSPC84 min
Aug 19, 6:05 PM EDTMesoscale DiscussionSPC55 min
Aug 21, 10:01 AM EDTMesoscale DiscussionSPC119 min
Aug 21, 11:28 AM EDTSevere Thunderstorm WatchSPC7 hr
Aug 21, 1:29 PM EDTSevere Thunderstorm WarningPHI76 min
Aug 21, 2:47 PM EDTFlash Flood WatchPHI35 hr
Aug 28, 9:16 AM EDTFlash Flood WarningPHI4 hr
Aug 28, 9:42 AM EDTAreal Flood AdvisoryPHI2 hr
Aug 28, 2:52 PM EDTFlash Flood WatchPHI14 hr
Oct 6, 3:19 PM EDTWind AdvisoryPHI29 hr
Oct 11, 2:33 AM EDTFrost AdvisoryPHI29 hr
Oct 13, 4:30 AM EDTFrost AdvisoryPHI24 hr
Oct 18, 2:04 PM EDTFreeze WarningPHI19 hr
Oct 19, 1:12 PM EDTFrost AdvisoryPHI18 hr
Oct 24, 3:30 PM EDTAreal Flood AdvisoryPHI4 hr
Nov 27, 3:16 PM ESTWind AdvisoryPHI24 hr
Dec 3, 5:41 AM ESTSevere Thunderstorm WarningPHI49 min
Dec 5, 3:25 AM ESTWinter Weather AdvisoryPHI19 hr
Dec 8, 3:05 AM ESTWinter Weather AdvisoryPHI30 hr
Dec 8, 2:40 PM ESTFlash Flood WatchPHI21 hr
Dec 9, 9:58 AM ESTAreal Flood AdvisoryPHI3 hr
Dec 9, 12:00 PM ESTWind AdvisoryPHI33 hr
Dec 12, 2:29 PM ESTWinter Weather AdvisoryPHI23 hr
Dec 13, 1:50 PM ESTFreezing Rain AdvisoryPHI4 hr
Dec 17, 3:30 PM ESTWinter Storm WatchPHI22 hr
Dec 18, 4:40 AM ESTWinter Storm WarningPHI46 hr
Dec 19, 12:27 PM ESTMesoscale DiscussionSPC6 hr
Dec 24, 3:04 PM ESTFreezing Rain AdvisoryPHI42 hr
Dec 28, 1:42 PM ESTWind AdvisoryPHI27 hr
Dec 31, 3:22 AM ESTWinter Weather AdvisoryPHI8 hr
Dec 31, 6:46 PM ESTWinter Weather AdvisoryPHI6 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.