700 hPa height (solid contours every 3 dam), temperature (dashed contours every 3oC), and Laplacian of temperature advection term (B) on RHS of QG Omega equation (shaded in x10-12 Pa m-2 s-1) (traditional form).
NCEP GFS analyses and forecasts on 1x1 latitude-longitude grid are smoothed with a 9-point local smoother run 30 times.