FLT CREW OF CARJ EXPERIENCE STATIC DISCHARGE FOLLOWING ENCOUNTER WITH ST ELMO'S FIRE. INCIDENT CAUSES MOMENTARY DISENGAGEMENT OF AUTOPLT AND OTHER SPURIOUS ANOMALIES. FLT CREW DECLARE EMER; CLB OUT OF CLOUDS AND DIVERT TO ANOTHER ARPT FOR INSPECTION BY CFR.

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WHILE DSNDING INTO XXX; APCH CTL ADVISED BELOW LNDG MINIMUMS FOR ILS RWY 5. RWY 23 WAS NOT USABLE DUE TO TAILWIND COMPONENT. WE WERE BEING RADAR VECTORED TO A HOLDING PATTERN. CONDITIONS WERE IN CLOUDS; LIGHT RAIN; LIGHT TURB. WX RADAR SHOWED SCATTERED LIGHT RETURNS. WHILE DSNDING FROM APPROX 13000 FT TO 10000 FT; WE BEGAN TO NOTICE ST ELMO'S FIRE ON THE NOSE OF THE ACFT. IT INTENSIFIED FOR A FEW SECONDS FOLLOWED BY A LOUD BANG AND FLASH. WE WERE BOTH BLINDED FOR A FEW SECONDS. THE AUTOPLT DISENGAGED; ELT ACTIVATED AND NOSE DOOR WARNING ILLUMINATED. WE DECLARED AN EMER AND REQUESTED A TURN BACK TOWARDS ZZZ AND YYY. ALSO; REQUESTED A CLB BACK TO 13000 FT TO GET ABOVE CLOUDS AND ICING CONDITIONS. WE THEN CHKED AND DETERMINED THAT ALL SYS WERE OPERATING NORMALLY (ENG; ELECTRICAL; HYDS; PRESSURIZATION). THE CAPT FLEW THE ACFT WHILE I PERFORMED ALL QRH PROCS. THE CAPT ALSO NOTICED THAT THERE WAS VISIBLE DAMAGE TO THE NOSE SECTION OF THE ACFT. AFTER A BRIEF DISCUSSION; WE DECIDED TO RETURN TO YYY BECAUSE OF THE AVAILABILITY OF LONG RWYS; VFR WX; AND CFR. WX IN ZZZ WAS DETERIORATING; WITH VISIBILITY 2 MI AND FOG. I NOTIFIED THE FLT ATTENDANT; MADE AN ANNOUNCEMENT TO THE PAX; AND TALKED TO DISPATCH. WE PERFORMED A NORMAL LNDG ON RWY 18R AT YYY WITH CFR STANDING BY. AFTER LNDG; WE STOPPED THE ACFT ON THE TXWY WHILE CFR PERFORMED A VISUAL INSPECTION. CFR NOTIFIED US THAT THERE WAS DAMAGE TO THE NOSE SECTION AND R STABILIZER; BUT IT WAS SAFE TO CONTINUE TO THE GATE. AS THE PAX DEPLANED; I STOOD IN THE DOORWAY AND BRIEFLY TALKED TO THEM. THERE WERE NO PAX COMPLAINTS OR SIGNS OF INJURIES.