Total Totals Index - -72 hr
This is a contour plot of total totals index with a contour interval of 2. The TT field shows instability in the atmosphere based on the lapse rate from 850 to 500 mb plus dewpoint at 850 mb. Where TTs are greater than 45, thunderstorms are possible. The higher the number, the more unstable the atmosphere is and as a result, the bold the thunderstorms could become. Values of 52 or higher indicate areas where severe thunderstorms are possible. Values <40 indicate areas of stable weather where skies are generally clear.