The 1000-mb prog is important for assessing warm/cold air advection, convergence, moisture and the low level wind among others. This prog shows four meteorological variables, which are temperature, dewpoint, wind and convergence. The 1000 mb forecast prog is available at: http://weather.unisys.com/nam/1000.php The temperature in Celsius is given using colors. The colors that are assigned to each temperature inclement are given below the panel. The aqua color represents temperatures from freezing to 4 degrees Celsius above freezing. Temperatures are given in 4-degree increments. Dewpoint is a little more difficult to interpret. Dewpoint is coded using different color lines and thicknesses of lines. You will see a thick solid white line and a thick red line and several other thinner lines of varying colors. The white thick line is the 15-degree Celsius isodrosotherm. The thick red line is the 0-degree isodrosotherm. The thick pink line is the -15 degree Celsius isodrosotherm. There are "thinner" colored lines between these thicker lines. Each line (thick or thin) represents a 5 degree Celsius dewpoint change. In general, temperatures and dewpoints will decrease when moving south to north across the forecast panel. Convergence on the prog is shown by a dark murky speckled color (this hides the temperature colors below it). Convergence is the coming together of air streams. Air that piles together in the low levels of the troposphere (which convergence does on the 1000 mb chart) results in UVV. Often convergence will be noticed in association with fronts, low-pressure systems and topographic convergence. The wind vectors on the panel can be used to assess (1) direction of windflow, (2) relative magnitude of thermal advection if a thermal gradient is present, (3) relative magnitude of moisture advection, (4) locating convergence and frontal boundaries, and (5) relative strength of the low level wind flow. |