Try this, if you have the Image Processing Toolbox.
x = [0 0 0 0 0 2 4 5 14 10 16 0 0 0 0 0 24 33 22 0 0 2 3 5 0 0 0 0]
props = regionprops(x > 0, x, 'Area', 'MeanIntensity')
numberOfRainPeriods = length(props)
stormLengths = [props.Area] % In hours
meanRainPerHour = [props.MeanIntensity] % In mm or whatever.
integratedRainTotalsPerStorm = stormLengths .* meanRainPerHour % In mm or whatever.
You get
numberOfRainPeriods =
3
stormLengths =
6 3 3
meanRainPerHour =
8.5 26.333 3.3333
integratedRainTotalsPerStorm =
51 79 10
