FATO40 NFFN 281500 TONGA AREA FORECAST VALID AUG 281700 TO 290800 UTC 2008. SITUATION: A S/SE WINDFLOW PREVAILS OVER THE AREA.MEANWHILE, A FRONTAL SYSTEM LIES SLOW MOVING OVER THE IAREA WIND: [SPEED IN KNOTS] FL140 26035M06 FL100 24020 FL070 16005 N OF 18S 27010 S OF 18S FL050 11005 N OF 20S 24010 S OF 20S FL020 14010 SIGWX: SCT SHRA. VIS : 40KM,10-15KM IN -SHRA, 8-10KM IN SHRA. CLOUD: FEW-SCT ST 008-012. FEW-SCT CU 015-030,TOPS 150-180. RISK ISOL CB 018-025, TOPS 350. FEW-SCT SC 030-050,TOPS 060. FEW-SCT ACAS ABV FL100. TAF NFTV 281500Z 281708 VRB03KT 9999 SCT020 SCT050 BECMG 2123 15012KT BECMG 0406 VRB03KT TAF NFTL 281500Z 281708 VRB03KT 9999 SCT020 SCT050 BECMG 2123 15012KT BECMG 0406 VRB03KT TAF NFTF 280917Z 281212 17008KT 9999 SCT016 SCT050 BECMG 2123 16015KT BECMG 0406 VRB03KT