Here is an image of the severe storm which impacted northern and central Shelby County around 8:30pm this evening.  This image shows the downward acceleration of the wind momentum and  the diverging signature of the winds once they reach the surface.  In the latter images you can see the stronger wind field expand toward Alabaster as it begins to move southeastward as a dominant outflow.

UPDATE:  Getting damage reports in from this same area.  Shingles off roofs, power lines down, and structure fires just NW of Alabaster near the Amberly Woods area.  This is all in association with the storm shown above.