Totals Totals Index

This cart is used to quickly assess the potential for severe weather. Total Totals represents a sum of the Vertical Totals and Cross Totals indices. Vertical Totals is the temperature difference (in degrees C) between 850 MB and 500 MB. The Cross Totals index is identical, except the 850 MB dewpoint is used instead of the temperature. The greater the difference, the more unstable the mid-level atmosphere. In addition, areas with surface dewpoints of greater than 65 F are hashed. The combination of susbtantial surface moisture along with highly unstable conditions aloft may provide a good chance for severe weather. Totals Totals indices of over 50 indicate a highly unstable mid-level atmosphere.