PVT INST RATED PLT LOST CTL OF THE ACFT DURING TKOF IN A XWIND RESULTING IN RUNNING OFF THE SIDE OF THE RWY INTO THE MUDDY GRASS MIDFIELD AREA BTWN PARALLEL RWYS.

Narrative

PREFLT AND TAXI WERE NORMAL. ENG RUNUP NORMAL. A B737 DEPARTED THE PARALLEL RWY (RWY 32L). WE WERE CLRED TO DEPART ON RWY 32R. THE WIND WAS FROM 240 DEGS. I NOTED THAT THE MIDFIELD WINDSOCK WAS FULLY EXTENDED; HOWEVER; THE WINDSOCK NEAREST ME WAS LIMP. THE INITIAL TKOF ROLL WAS NORMAL. AT ROTATION SPD; THE NOSEWHEEL CAME OFF THE GND; THEN THERE WAS AN IMMEDIATE VEER TO THE L. MY INITIAL THOUGHT WAS THAT THE L MAIN TIRE HAD BLOWN. THE SENSATION WAS ONE OF LOSS OF LIFT; ACCOMPANIED BY WHAT FELT LIKE A STRONG PUSH ON THE L SIDE OF THE TAIL. I IMMEDIATELY GAVE FORCEFUL R RUDDER. SINCE THE NOSEWHEEL WAS NOT IN CONTACT WITH THE GND; THERE WAS NO STEERING EFFECT. ALSO; I DON'T BELIEVE I HAD RUDDER EFFECTIVENESS; AS THE NOSE DID NOT COME AROUND TO THE R. BY THIS TIME; IT WAS OBVIOUS THAT WE WERE DEPARTING THE RWY INTO THE GRASS. THEREFORE; I LEVELED THE WINGS; BROUGHT THE PWR TO IDLE; AND SETTLED INTO THE INFIELD GRASS (BTWN RWY 32L AND RWY 32R). BECAUSE OF HVY RAIN THE NIGHT BEFORE; THE ACFT BECAME MIRED IN THE MUD; BENDING THE INNER GEAR DOORS. THE GND OPS CREW PULLED THE AIRPLANE FROM THE MUD; AND THE PLANE WAS TAXIED BACK TO ITS HANGAR UNDER ITS OWN PWR. THE ACFT SUSTAINED MINOR BENDING OF THE 2 INNER MAIN GEAR DOORS; AND ADDITIONAL DAMAGE TO THE R OUTER GEAR DOOR. ALSO; THERE WAS MINOR SCRAPING OF SHEET METAL BENEATH THE R ELEVATOR; PRESUMABLY FROM GRASS/BRUSH CONTACT. THERE WAS NO AIRFOIL; ENG; PROP DAMAGE; THERE WERE NO INJURIES. THERE WERE NO OTHER ACFT INVOLVED. I BELIEVE THAT AT ROTATION THERE WAS A SUDDEN WIND CHANGE FROM WNW; TO THE SSW. THIS RESULTED IN LOSS OF LIFT AND AIRSPD; AS WELL AS DIRECTIONAL CTL. ALSO; THERE MAY HAVE BEEN WAKE TURB FROM THE PRIOR JET DEP THAT WAS BLOWN ACROSS MY RWY. I BELIEVE THE ACFT WOULD NOT HAVE SUSTAINED ANY DAMAGE IF THE GND WERE NOT SATURATED FROM THE PREVIOUS RAIN. I DID NOTE THAT THE NEXT ARRIVING ACFT LANDED TO THE S; INDICATING A CHANGE IN WIND DIRECTION. I BELIEVE MY ACTION TO LEVEL THE WINGS; REDUCE PWR AND 'FLY THE AIRPLANE' PREVENTED A MORE SERIOUS INCIDENT FROM OCCURRING. PERHAPS WAITING AT THE END OF THE RWY LONGER OR WAITING UNTIL THE WINDS DECREASED COULD HAVE PREVENTED THE INCIDENT.