000 FTUS43 KGRB 171721 TAFGRB TAF KGRB 171721Z 1718/1818 23014G20KT 6SM -SHRA BR OVC020 FM180100 28018G25KT P6SM OVC015 FM180900 27008KT P6SM BKN080 FM181400 27010KT 6SM -SHRA BKN050=