The National Weather Service says there is a 40-90% chance for numerous rounds of widespread rain and thunderstorms Saturday through Monday.
With uncertainty in the exact location of each round, rainfall amount spreads are high.
In this graphic you can find a low-end scenario, high-end scenario and a reasonable average scenario of rainfall amounts for the Houston area.
Generally, highest amounts will be north of I-44 where there is a 50-70% chance for most places to receive more than one inch of rain by the end of Monday.