The image of the buildings faded as the pressure decreased, losing itself in the dark.
If the pressure in the front arm decreases then you are sailing too close to the wind.
Also, a line might start wide and taper off as the pressure decreases.
As the air inside the balloon expands, its pressure decreases.
In general as the pressure decreases, so does the temperature required to boil a liquid.
In a gas expansion the pressure decreases, so the sign of is negative by definition.
This may be what is leading you to think the pressure in the balloon has decreased.
Since energy has been extracted from the fluid, the pressure must have decreased.
In the atmosphere, the pressure of the air decreases with increasing altitude.
As the velocity of a fluid increases, its pressure will decrease.