Clues:
 A. Discrete "Mom" enabled smuggling back weather monitoring gear (10)
 B. Crosby broken by heavy weather looking for ideas (13)
 C. Top hill conqueror? (6)
 D. Novel is a dry read, lacking structure (10)
 E. I pouted sexily, furtively, swiftly (13)
 F. Start of fancy arcade right out the front (6)
 G. Lot's lad working the rag (6)
 H. Gal's lad working the rag (6)
 I. One subsequently retained for each less able (8)
 J. Fellow embraces some trigonometry just for a laugh (6)
 K. He had laws for stars: keep active, engaging left and right (6)
 L. The ghoul is terrible in a building with lots of stairs (10)
 M. Company is too moral - revolutionary! (8)
 N. Perhaps Scottish throne is in a mess, run without heart (8)
 O. Played set of Fab Four and "Two" typically (8)
 P. Stirring sleepers with unique gifts... (8)
 Q. ...abandoned duvet (left down) (4)
 R. I'd leave with King, stirred so rudely from slumber! (4)
 S. Compacts with last of Paris French who troubled Hess (8)
 T. Showing unity... got there somehow! (8)
 U. Turin always offered convenience (6)
 V. Grave mistake to embrace total change of direction, showing less certainty (6)
 W. Rushed in where many get fleeced, took heroin and spent large (8)
 X. Strange hope in a box and fear of something else (10)
 Y. No time for culture, although sometimes they have it in parliament (4)
 Z. Zionist leader one backed as source of contradictions (4)