When earth is parched it often repels the water it needs, which just glances off the surface.  If rain persists, sooner or later that drought-hardened crust is softened and then the soil goes into soak mode, sponging up showers.  I liked Nicolson’s description of the sad-eyed pools that form before the dried out surface is soothed open. 

Where in winter the rain doesn’t soak into a delicious, light, open soil structure but lies on its surface in sad-eyed pools.

Source: Adam Nicolson, Sissinghurst: An unfinished history (London: Harper Press, 2009), p. 147