Unknown object spotted while reviewing photo of clouds/shower line taken earlier in day.

I was outside shooting a line of showers just to the south of me and moving west to see how much detail showed up. I'm always testing the limits of my camera. I took a few shots of this same area and saw nothing but clouds and showers during the shoot.
It wasn't until I transferred the photos to the computer and looked at them that I saw a thin dark line in one shot. I cropped the image to 100% and cleaned up the image noise almost entirely but couldn't identify the object. I posted the photo and crops of the photo to the astronomy forum I'm registered with online (Cloudynights.com)but no one there has identified it yet. I figured someone would recognize it as a plane or something but it still remains un-named.
 I am approx 12 miles NW of FLL airport and planes on final approach usually fly west right over my house or a few miles to the south prior to circling south and finally east towards the airport. I see what might be a hint of front landing gear to the lower right of the object but it could be remaining image noise. It's possible that this is a plane heading west prior to circling south for final. It's odd that theres no hint of a tail but it could be hidden by the clouds. The entire bottom of the object is dark but it could be a plane painted dark blue on the bottom and viewed directly from the side. I do take photos of passing jets sometimes and there are a few with dark painted bottoms.
 Either way...I can't identify it for certain or get any more detail from the image. In all probability it is a plane. I'm sure your organization has access to flight plans and approximate location of planes at certain times...and the exact time of the photo is embedded in my EXIF data. Image was taken with a SONY DSC-H1 at 5mp (also in EXIF DATA).
Please advise whatever you find out.
Thanks for you time.
((name deleted)
Witness provides no contact information.  PD