Saw this effect once in my LNC2 after having to park it outside for a week - during which a real frog-strangler of a rain storm ocurred. During the storm, the wind was blowing the rain horizontally and right at the side of the fuselage - and aparently right into the static port on that side. After an aborted take-off and some head-scratching, I disconnected the static lines (not too hard to do on a LNC2, not sure about the IV) and found about two ounces of water in the lines, fortunately in the rear of the aircraft where the two sides come together and where I had purposely put the tee about 18 inches below the ports. After getting it all out (and changing my shorts), problem solved.

Dan Schaefer
LNC2    N235SP