Big Boom: Lightning Strikes, Hail Near AccuWeather HQ

UPDATE: AccuWeather.com's Elliot Abrams also talked to someone at the Penn State Golf Course across the road who thought that the strike might have hit the new clubhouse under construction. I also considered the water tower which is in the area.

Tuesday was a fairly eventful day for severe weather in Pennsylvania, despite the SPC only having a tiny sliver of the Northeast part of the state in a Slight Risk very late in the day. The north/central parts of the state were in a General Risk. Storms started to break out in the north-central part of the state in the afternoon and two major storms moved through State College, Pennsylvania, home of AccuWeather HQ [Google Map]. At 1:26 PM, a large lightning strike hit about 2,000 feet behind our building. I was running a video camera pointed out my window at the front of the building, so you can only see a flash, but you can hear the boom overdrive the mic and drone on for a while.

People across much of the town reported hearing the strike. It was a "positive stroke" which are known for being louder, brighter, and causing more damage than their more-common cousins, the negative strokes. According to lightning data from Vaisala, the lightning strike had an amperage of 58000 amps, in my experience higher than average but not extraordinary. Based on Vaisala's accuracy discussed last year, their location of the strike was almost assuredly correct when including their "confidence ellipses."

To try to hone it in a little more, I ran the audio through Camtasia Studio Pro which said that the time from the lightning strike to the thunder was 52 frames at 30 fps which would be 1.79 seconds. Sounds travels at 1135.17 feet per second at 82 degrees which calculates out to 2032 feet.*

Where was the strike exactly? However as my colleague Mike Sager points out: Lightning is a 3-d object; it's possible that it came as close as 2000 feet in the air before it veered off to hit the ground where Vaisala says it did; we can't know without a photograph. The inherent inaccuracies of video/audio and the fact that sound travels slightly faster or slower depending on temperature and humidity also complicate the matter. I am reasonably sure based on reports from AccuWeather HQ and a building across the street that the strike was in this direction, behind the building. I have drawn a transparent square around the area where my best guess is.

And that wasn't our last storm for the day. Around 3:15 another one rolled through, this one with pea to marble-sized hail according to reports on the Pennsylvania Storm Chasers Facebook Group. A couple photos were shown there as well, including these taken by AccuWeather.com on-air personality Angelica Campos. I can tell you from living here for 13 years that hail in Centre County is very rare and I was impressed with these pictures. I would have been out chasing it but - wouldn't you know - I was sitting in a meeting at work when it happened!

There were only a couple of NWS Spotter reports, one of 65 mph winds east of Allentown and another of trees down in Susquehanna County. On the Pennsylvania Storm Chasers Facebook Group, Matrona reported "70 mph wind damage here in Wilkes Barre" (Luzerne County). You can see a state-wide radar loop for the day on the Pennsylvania Storm Chasers homepage. Lightning was fairly common with these storms in the NE quadrant of the state.

A closeup zoom with AccuWeather.com RadarPlus (loop | | zoomed-out loop | download zoomed-out loop of the 3:15 storm shows the strong reflectivity signature indicating hail over North Atherton Street, which was confirmed by the Facebook Photos.

Note in the radar loop below (download loop) how this storm cell took a sudden turn south just before it got to me. I'm not sure why that happened.

*Since one mile = 5280 feet, the old adage that 5 seconds equals one mile is pretty close - 5675.85 at 82 degrees, slightly less or more depending on the temperature and humidity.