2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/2049We combine AAVSO and VSS/RASNZ optical and Extreme Ultraviolet Explorer EUV light curves of dwarf novae in outburst to place constraints on the nature of dwarf nova outbursts. From the observed optical-EUV time delays of 0.75-1.5 days, we show that the propagation velocity of the dwarf nova instability heating wave is ~ 3 km/s.5 pages including 2 tables and 11 encapsulated postscript figures; LaTeX format, uses newpasp.sty; submitted for inclusion in the proceedings of "Evolution of Binary and Multiple Star Systems."Astrophysicstext