Farts first thing in the morning that are high pressured, in high quantity and sometimes high pitched or squeeky. Often caused by your guts digesting overnight and disturbed by the sound of your alarm clock.
Getting ready for work in the morning and releasing the pressure from your bowel, "I've got a case of the pressure farts this morning"
The onset of farts due to eating a large quantity of vegetables
"Oh no, I've got veg air!"
After eating a roast dinner-"I'm going to have veg air later"