I know this is late, but I just found your website. I think this may have been what I saw. I had another friend who saw it from a parallel bridge at the same time. We described the same things. I searched through my Facebook posts so I could find the exact date and time.
Location
Address
Van Buren, AR
Latitude
35° 25' 8.12'' N (35.418922°)
Longitude
94° 21' 8.26'' W (-94.352294°)
Elevation
123.135m
Time and Duration
Local Date & Time
2012-12-10 19:00 CDT
UT Date & Time
2012-12-11 01:00 UT
Duration
≈3.5s
Direction
Moving direction
From up right to down left
Descent Angle
194°
Moving
Facing azimuth
47.64°
First azimuth
47.52°
First elevation
32°
Last azimuth
47.19°
Last elevation
17°
Brightness and color
Stellar Magnitude
-21
Color
Green, Light Green, Yellow, Light Yellow
Concurrent Sound
Observation
Unknown
Remarks
-
Delayed Sound
Observation
Yes
Remarks
a boom
Persistent train
Observation
Unknown
Duration
-
Length
-
Remarks
-
Terminal flash
Observation
Yes
Remarks
It almost looked like the Northern Lights which is rare for this area, and nothing had been reported. I just found this site and here is the Facebook post I did that evening as soon as I got home. "I think we just saw northern lights?!?! Crossing the Arkansas river coming into Van Buren and saw first a big flash of green and yellow up and down line and then a few seconds later a big explosion of green light. Anyone else? I know we can see them here every once in awhile."
