TIG’s Lair

all text stolen from UNISYS pages

The 1000 mb chart also shows near surface weather conditions. The parameters plotted are 1000 mb temperature in Celsius (in color contours), convergence (black lines, interval=2, shaded > 0), 1000 mb dewpoints in Celsius (colored lines, interval=5, bold orange=20, bold white=15, bold red=0, bold magenta=-15, bold gray=-30) and winds plotted as vectors.

The 700 mb chart shows the forecasted vertical velocities (colors), heights (bold white lines), temperature in Celsius (thin red lines) and wind vectors.

The 850 mb chart shows weather conditions at the 850 mb level or around 5000 feet above sea level. The parameters plotted are
temperatures in Celsius (in color contours), heights in white lines and winds plotted as vectors.