700 hPa streamfunction (thin black contours every 2x106 m2 s-1, negative dashed, positive solid), potential temperature (solid contours every 2oC, positive red, negative purple), nondivergent wind (standard barbs in knots), resultant deformation (thick black contours every 4x10-5 s-1 starting at 8x10-5 s-1), and 2D frontogenesis [shaded in oC (100 km)-1 (3 h)-1). Deformation, frontogenesis, and potential temperature are smoothed using a 9-point local smoother run 5 times.
These plots are derived from the NCEP GFS analyses and forecasts on a 0.25x0.25o latitude-longitude grid.