12Z May 1

  1. On the surface map, the surface low is now apparent. On the 500-mb height-vorticity map, the trough is also now apparent (there is a definite sag equatorward in the 500-mb heights over the Rockies). Do you think curvature has become more or less important in generating relative vorticity associated with the absolute vorticity maximum (of magnitude 16x10-5 sec-1 in eastern Idaho?

  2. Before we leave the 500-mb height-vorticity map, there's another vorticity center taking shape over the West, but it's not marked yet! Let's see if we can find it! What is the value of the isovort going through northwestern Arizona? Is the value of the absolute vorticity near the juncture of the Nevada, Utah and Arizona borders larger or smaller than the value of this isovort? Thus, conclude whether the region in northwestern Arizona that is bounded by the dashed line is a relative maximum or relative minimum in vorticity. Keep this in mind as we go to the next set of maps.

  3. Use the surface map to determine where the largest temperature gradient is in Nevada and Utah: in the northern or southern half of these states? Recall that cold fronts are typically placed at the leading edge of the cold air (that is, on the warm side of the zone of largest temperature gradient). Is the linear cloud formation on the infrared satellite image at this time consistent with where the cold front should be placed?