Smoke

More good reporting/writing by Teflon Don on why Friday in Iraq is the day for car and truck bombs:

"There’s all kinds of smoke in Iraq. There’s the plumes that signify a fire- white for wood or reeds, black for vehicles, and grey for buildings. Mushroom clouds mean a bomb of some sort- white or grey, especially with a lot of dust, for an IED, and black for car bombs."

UPDATE  Omar at Iraq the Model on why the chlorine bombs, which TD also refers to, could be a good turning of the screw for us.