Alert archive / Pennsylvania / Mesoscale Discussions / 2021

Mesoscale Discussions in Pennsylvania, September 2021

19 mesoscale discussions in September 2021. An alert counts here when it covered any part of the state, so the counties below add up to more than the state. The archive of mesoscale discussions reaches back to 2003.

Mesoscale Discussions by county

Each county as a circle sized by its count in September 2021. Tap one for its archive.

Mesoscale Discussions
19
Busiest day
September 1, 20214 mesoscale discussions

Over time

By day

Days in UTC, the clock the archive keeps.

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.

IssuedProductOfficeCountiesLasted
Sep 1, 4:01 AM EDTMesoscale DiscussionSPCChester, Delaware, Lancaster, York119 min
Sep 1, 3:09 PM EDTMesoscale DiscussionSPCBucks, Chester, Delaware, Montgomery, Philadelphia3 hr
Sep 1, 4:28 PM EDTMesoscale DiscussionSPCDelaware, Philadelphia2 hr
Sep 1, 6:34 PM EDTMesoscale DiscussionSPCPhiladelphia56 min
Sep 8, 4:15 PM EDTMesoscale DiscussionSPCBerks, Carbon, Chester, Columbia, Dauphin, Lackawanna and 12 more2 hr
Sep 8, 9:25 PM EDTMesoscale DiscussionSPCBerks, Bucks, Lehigh, Monroe, Montgomery, Northampton and 1 more95 min
Sep 8, 10:42 PM EDTMesoscale DiscussionSPCBerks, Bucks, Chester, Delaware, Lancaster, Lehigh and 2 more2 hr
Sep 13, 12:26 AM EDTMesoscale DiscussionSPCSusquehanna94 min
Sep 13, 4:11 PM EDTMesoscale DiscussionSPCCameron, Clinton, Elk, Erie, Forest, McKean and 2 more2 hr
Sep 13, 7:07 PM EDTMesoscale DiscussionSPCCarbon, Centre, Clearfield, Columbia, Jefferson, Luzerne and 5 more113 min
Sep 15, 10:33 AM EDTMesoscale DiscussionSPCBedford, Berks, Blair, Bradford, Cambria, Carbon and 32 more2 hr
Sep 15, 4:38 PM EDTMesoscale DiscussionSPCBlair, Carbon, Centre, Columbia, Cumberland, Dauphin and 18 more67 min
Sep 15, 8:11 PM EDTMesoscale DiscussionSPCAdams, Berks, Carbon, Lancaster, Lebanon, Lehigh and 3 more2 hr
Sep 22, 1:08 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 8 more3 hr
Sep 22, 4:08 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 10 more97 min
Sep 22, 6:13 PM EDTMesoscale DiscussionSPCArmstrong, Butler, Clarion, Crawford, Erie, Forest and 5 more92 min
Sep 23, 3:13 AM EDTMesoscale DiscussionSPCAdams, Berks, Chester, Cumberland, Dauphin, Lancaster and 3 more5 hr
Sep 23, 10:30 AM EDTMesoscale DiscussionSPCBerks, Bucks, Carbon, Chester, Delaware, Lehigh and 3 more2 hr
Sep 23, 1:29 PM EDTMesoscale DiscussionSPCBucks, Northampton, Philadelphia61 min

By county

Every county with at least one alert. A county page lists each alert that covered it.

27 more counties

Nearby

Alerts in force nowTornadoes on recordThe radar archive20202022

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.