I started to write something about Bernoulli, then remembered this is compressible flow which is hard. Much consternation over fluid mechanics can be avoided by following this guy's advice about assuming choked flow (exit velocity = Mach 1) at the window, because your P/P0 will be less than the critical value 0.528 (assuming P=3.98 psi at 32,000 ft from a standard atmosphere calculator and P0 = 8 psig in the cabin based on the differential pressure gauge from a 737 overhead panel).
https://www.physicsforums.com/threads/velocity-of-air-coming-out-of-a-nozzle.694656/
Solving for mass flow rate and then applying the General Thrust Equation for a constant mass flow rate...
https://www.grc.nasa.gov/www/k-12/airplane/thrsteq.html
...(which may or may not be a totally wrong assumption
) with V0=0 m/s, Ve=Mach 1 at 32,000 ft on a standard day and the intake and exit pressures above, I get a thrust force of 1885.65 lbf. To be honest I'm surprised I'm not several orders of magnitude off, especially since I converted back and forth between SI and imperial units in between a couple steps because some of the thermo constants confuse me in imperial. I also used a bigger window area of 113.9 in^2 based on some 737 window googling, which would get me to within ~700 lbs of
@nibake 's pressure = force/area assumption.
That being said, you are flying in a 133,000 lb airplane. Keeping things in perspective, the point load from that "window thrust" is only 1% of the total lift force on the wings. You almost certainly get more side-load flying through turbulence. And since it's acting near the center of gravity (and thus the yaw axis) the yawing moment contribution is virtually nil.