Back to Maps

300-200 hPa layer-mean potential vorticity (solid gray contours every 1 PVU) and irrotational wind (arrows in m s^-1), 250 hPa wind speed (shaded in m s^-1; green=30, yellow=40, orange=50, pink=60, white=70) and relative humidity (shaded according to the grayscale in %), and 600-400 hPa layer-mean ascent (red contours every 0.3 Pa s^-1 starting at -0.3 Pa s^-1). The PV is smoothed with a 9-point local smoother run 5 times.
These plots are derived from the NCEP GFS analyses and forecasts on a 0.25x0.25^o latitude-longitude grid.