1: Flower - say, in Victoria's province - to raise (9)
6: Rapidity with which heat's dissipated (5)
9: Argue about something boring (5)
10: Indian chief fending off some respected Turk (7)
11: Clearances for the first couple of characters to find answers. (11)
13: Call initially communicates real yearning (3)
14: Prepare for onset of torrential downpour (5)
15: One in Canada, peut-tre? (7)
18: Simplest to find English in kinky siesta (7)
19: Drive carefully and live (5)
21: Bumped into yours truly at junction (3).
22: Girl mostly into turning inside out - it's never ending! (11)
23: Sibling rivalry's beginning - worry about it (7)
25: Emblem of sovereignty that was a quarter-pounder? (5)
26: Performer causes agent to lose head (5)
27: Vulgar and insipid (9)