Second article in a series that discusses the technical aspects of rainfall.
Just as one can see on visual weather chart presentations, TV Weather for instance, lines of equal pressure, isobars, so lines of equal temperature, isotherms, are found in climatological atlases so will one find isohyets, lines showing equal rainfall.

What happened?
Two vortices were in consideration a week ago. One followed the expected pattern: that was during the weekend. The second picked up strength and brought very cold air deep into the country. Such cold should have brought cloud and resultant rain to the far south. The cold was more efficient and the rain optimism fell short.