Wind at 900 hPa This map shows the average wind vector at 900 hPa for every modeled gridpoint (ca. 80 km). Based on the average SLP of about 1010 hPa the equivalent pressure altitude for 900 hPa would be at about 900m a.s.l. (ca. 3000 ft). This map is very useful for gliders and hang-gliders, if their airfield or starting pad is at a low altitude. (wind-converter)