This might be what a lahar / debris flow coming down from the glaciated ice sheet on top of 3,286 m (10,781 ft) Mount Baker Stratovolcano. It would likely look like:
13 July '11: Mer de Glace Debris Flow
https://youtu.be/SK0ZtaDPzZw [9:00 minutes]
Bruce Reeves
Published on Jul 31, 2011
The two summits are located on the west ridge of the Aiguille Verte (4,122 m) and are connected to each other by the Brèche du Dru(3,697 m). The north face of the Petit Dru is considered one of the six great north faces of the Alps.
:
Debris Flow above Mer de Glace Glacer, below Les Drus peak, near Chamonix, France, shot from about 500 yards away. Significantly condensed; debris flow continued for over 45 minutes. [Wikipedia: TThe mountain's highest summit is Aiguille du Dru (also the Dru or the Drus; French, Les Drus) is a mountain in the Mont Blanc massif in the French Alps. It is situated to the east of the village of Les Praz in the Chamonix valley. "Aiguille" means "needle" in French.- Grande Aiguille du Dru (or the Grand Dru) 3,754 m
Another, slightly lower sub-summit is:
- Petite Aiguille du Dru (or the Petit Dru) 3,733 m.
At 3,286 m (10,781 ft), Mount Baker Stratovolcano is the third-highest mountain in Washington and the fifth-highest in the Cascade Range, if Little Tahoma Peak, a sub-peak of Mount Rainier, and Shastina, a sub-peak of Mount Shasta, are not counted.