Frontogenesis is the development
of a new front or the intensification of an already existing front. Generally,
if the contrast between two air masses becomes greater, frontogenesis has
Frontogenesis can be identified in many ways, most of
which involve the comparison of current surface charts to previous one.
Thickness isopleth gradients.
Frontogenesis is indicated by the tightening of thickness
isopleth gradient across charts. (Thickness isopleths are closer together
on the current 1000-500 mb thickness chart than on the previous charts).
Gradient tightening implies an increase in temperature advection and more
temperature contrast between the air masses.
Frontogenesis is also indicated by tightening on a surface
chartís isothermal analysis. (Isotherms on the urrent surface chart are
more closely spaced than previously).
Frontogenesis can also be seen through isobar gradient
tightening and/or an increase in cyclonic curvature across current and
Skew-Tís are another good tool to identify frontogenesis.
If the frontal (temperature) inversion indicated by a Skew-T increases
(becomes warmer with height) on the current Skew-T than it was on the previous
Skew-T, there is greater temperature contrast between the two air masses,
which indicates frontogenesis.