ARA independent gasoil stocks are the canonical European distillate balance indicator, but they are noisy week to week. The signal that matters is the four-week change versus seasonal norm.
When ARA stocks build counter-seasonally for three consecutive weeks, the prompt timespread tends to weaken into contango within a fortnight. When they draw counter-seasonally, expect backwardation to steepen and the front of the curve to rally relative to flat price.