FOKKER 100 FLC DURING FINAL APCH DIVERTED TO ALTERNATE DUE TO TSTM DOWNBURSTS AND RPTED WINDSHEAR.

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5-10 MI FINAL RWY 8 IAH APCH. AFTER WX RERTE; 25 MINS OF HOLDING W OF IAH; WE WERE CLRED INBOUND TO IAH. LINE OF SEVERE TSTMS N TO NW OF FIELD MOVING S. AS WE LINED UP ON RWY 8; CLRED FOR THE VISUAL; WE LOOKED DOWN TO THE L AND SAW A HUGE GUST FRONT/MICROBURST BASED ON BLOWING SAND AND DIRT; PLUS HVY RAIN/LIGHTENING APCHING THE N END OF THE FIELD. WINDS OF 010 DEGS AT 25 KTS GUSTING TO 33 KTS WITH RAIN. THIS IS 13 KTS MORE THAN THE XWIND LIMIT FOR THE F100. IMMEDIATELY TOLD TWR WE NEEDED A R TURNOUT. HE SAID UNABLE DUE TO AN ACFT OFF THE R FOR VISUAL RWY 9. ABOUT THE SAME TIME; A WIND GUT HIT THE ACFT FROM L TO R BLOWING US SLIGHTLY R OF COURSE. WE ADVISED THE CTLR/TWR WE WOULD HAVE TO DECLARE AN EMER FOR THE R TURNOUT. HE TOLD US TO KEEP A VISUAL ON THE ACFT GOING TO RWY 9. WE SAID WE COULD. DURING THE BREAKOUT; WE PASSED WELL BELOW AND BEHIND THE RWY 9 TFC WITHOUT EVEN RECEIVING ANY TCASII RA'S. WE WERE THEN GIVEN A HDG CLR OF THE ARPT AND WX THEN CLRED TO OUR ALT (SAT). LATER RPTS OF GOLF BALL SIZE HAIL IN THE AREA.