Wind tiles for Aviation Weather. Based on NOAA GFS 0.25° data, public domain. NOAA does not endorse this service. Changed: u, v in knots, T in °C, coarsened to 0.5° and 1°, 8 bits per value, masked below ground. Derived: turbulence index (Ellrod TI1), icing potential from T and RH, freezing level in hundreds of feet, thunderstorm index from CAPE and convective precipitation rate, its zones, CAPE and rate widened by 0.5°; turbulence and icing at 0.5° and 1° take the maximum around each node.