This is an example of the Digital Vertically Integrated Liquid (DVIL) derived product. DVIL is a vertical integration of reflectivity values within the full depth of a thunderstorm, with values converted to equivalent liquid water. DVIL is useful to identify storms containing hail and a large liquid water content (i.e., deep, tall storms). It helps differentiate the relative strength and depth of storms. Limitations exist, but it gives NWS forecasters a quick assessment of storms in an area.
Above, DVIL is shown for several thunderstorms in north-central Kentucky in April 2011. The storm with the light brown color in Nelson County was severe, and had the highest DVIL values compared to other storms nearby. The storm southeast of Elizabethtown in Hardin County also was strong. Other cells had lower DVIL values and were weaker at this time. DVIL trends over time are very important and indicate growing or decaying storms. In fact, a storm with lowering DVIL values could be a collapsing cell about to produce a microburst before weakening. Intensifying storms (strong updrafts) would show increasing DVIL values.