In order for there to be a class E surface area at an airport, there
must a published instrument aproach procedure in addition to weather
observations and ATC communications.

The entire purpose of a Class E surface area is to protect an aircraft
descending out of the clouds on an instrument approach. The higher VFR
weather minimums within a Class E surface area give the pilot on
approach a better chance to see and avoid traffic after going visual.
You will never be cleared for Special VFR while an aircraft is on an
instrument approach for the same reason. Class E surface areas are
designed to keep one from breaking out at 400 AGL and being nose to
nose with a crop duster.

Keeping the reason for Class E surface areas in mind aids in
understanding thier requirements and unsual shapes.