A TWR CTLR CLAIMS THAT THE ASOS WAS GIVING ERRONEOUS WIND DIRECTION AND VELOCITY WHILE A C172 WAS LNDG. THE RPTR ISSUED NEW WX TO THE C172 BASED UPON HIS OBSERVATIONS.

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CESSNA HAD JUST TURNED BASE TO FINAL TO RWY 16 HAVING BEEN CLRED TO LAND ON DOWNWIND ISSUED WIND 100 DEGS; 8 KTS. ASOS WX WAS 100 DEGS 8 KTS 10 SM FEW 17 19/16; ALTIMETER 29.74. IN ACTUALITY NO PORTION OF SKY VISIBLE THROUGH CLOUDS; ALL ESTIMATED AT LESS THAN 12000 FT. TSTM ABOUT 3 MI W OF FIELD. FELT TWR BUFFETED BY WIND. ISSUED TO PLT BASED ON OBSERVATION OF ASOS AND PARKING LOT 'ASOS WIND VARIABLE AT 4 KTS; IN REALITY IT'S BENDING TREES.' ACFT REQUIRED 3200 FT OF RWY TO LAND. ON TOUCHDOWN ASOS STILL READ VARIABLE AT 4 KTS. AS ACFT EXITED RWY ASOS UPDATED TO 250 DEGS 9 KTS GUSTING TO 16 KTS; 200V280; AND THEN TO 270 DEGS 15 KTS GUSTING TO 21 KTS. NOTE THAT THE ORIGINALLY ISSUED WIND WAS 170 DEGS DIFFERENT FROM THE ACTUAL WIND AT TIME OF LNDG AND AT 2.5 TIMES THE VELOCITY AND APCHING THE ACFT'S DEMONSTRATED XWIND LNDG CAPABILITY; NOT TO MENTION WITH A TAILWIND COMPONENT RATHER THAN THE EXPECTED HEADWIND COMPONENT. I BELIEVE THAT THE INABILITY TO ISSUE REAL TIME INFO CREATED A HAZARDOUS SIT. THE ONLY VALID INFO THE PLT HAD IN THIS CASE WAS MY NOTABLY UNAUTH REMARK.