As expected, some moderate-to-strong thunderstorms have developed across the Houston area this morning as a weak cold front sags closer to the region. This unsettled pattern will persist throughout the day and likely Sunday as the atmosphere is very moist.
Due to some especially heavy thunderstorms over northeastern Harris County, where in excess of 4 inches of rain have fallen since midnight, the National Weather Service has had to issue a flash flood warning until 11 am.
Strong storms have also developed near Sugar Land and Katy this morning. Most areas are not going to see nearly so much rain as 4 inches, but the flood warning warning illustrates the potential for heavy rainfall due to the abundant tropical moisture in our atmosphere. Basically, the advice Matt gave yesterday holds for this weekend—bring an umbrella, and be prepared to have outdoor activities disrupted due to periods of inclement weather.