A plow apparatus for use with a vehicle, said plow apparatus comprising: a support frame configured to couple to the vehicle having a forward travel direction and vertical and lateral axes perpendicular to the forward travel direction; a debris-pushing plate assembly coupled to said support frame and comprising: a center plate having a center portion coupled to said support frame; an extendable plate having a first end pivotably coupled to an outboard end of said center plate and pivotable about a sweep axis that is parallel to the vertical axis of the vehicle, characterised in that a second end of said extendable plate is pivotable more than one-hundred eighty degrees about the sweep axis and said extendable plate is pivotable between a stowed configuration in which said extendable plate extends laterally inboard alongside and parallel to said center plate, and a plurality of extended debris-clearing positions in which said extendable plate is laterally outboard of said center plate; and a sweep actuation mechanism comprising a sweep actuator coupled between said extendable plate and said center plate and operable to pivot said extendable plate about the sweep axis ; wherein said apparatus is operable to clear snow or debris from a ground surface adjacent the vehicle with said center plate and said extendable plate in both the stowed and extended configurations. a support frame configured to couple to the vehicle having a forward travel direction and vertical and lateral axes perpendicular to the forward travel direction; a debris-pushing plate assembly coupled to said support frame and comprising: a center plate having a center portion coupled to said support frame; an extendable plate having a first end pivotably coupled to an outboard end of said center plate and pivotable about a sweep axis that is parallel to the vertical axis of the vehicle, characterised in that a second end of said extendable plate is pivotable more than one-hundred eighty degrees about the sweep axis and said extendable plate is pivotable between a stowed configuration in which said extendable plate extends laterally inboard alongside and parallel to said center plate, and a plurality of extended debris-clearing positions in which said extendable plate is laterally outboard of said center plate; and a sweep actuation mechanism comprising a sweep actuator coupled between said extendable plate and said center plate and operable to pivot said extendable plate about the sweep axis ; wherein said apparatus is operable to clear snow or debris from a ground surface adjacent the vehicle with said center plate and said extendable plate in both the stowed and extended configurations. a center plate having a center portion coupled to said support frame; an extendable plate having a first end pivotably coupled to an outboard end of said center plate and pivotable about a sweep axis that is parallel to the vertical axis of the vehicle, characterised in that a second end of said extendable plate is pivotable more than one-hundred eighty degrees about the sweep axis and said extendable plate is pivotable between a stowed configuration in which said extendable plate extends laterally inboard alongside and parallel to said center plate, and a plurality of extended debris-clearing positions in which said extendable plate is laterally outboard of said center plate; and a sweep actuation mechanism comprising a sweep actuator coupled between said extendable plate and said center plate and operable to pivot said extendable plate about the sweep axis ; wherein said apparatus is operable to clear snow or debris from a ground surface adjacent the vehicle with said center plate and said extendable plate in both the stowed and extended configurations. <EOS>