Some of the moisture was initially brought into Texas by Hurricane Alex. Now strong southeast winds are adding to the soggy situation by bringing very moist air in from the Gulf of Mexico. Meanwhile, winds in the upper atmosphere are blowing from the northwest and this is causing moisture to converge in the Houston area, producing squalls of heavy rain.
Most neighborhoods around Houston have picked up 3-5" of rain over the last three days. Bayous are running high in Harris County. Over 10" of rain has fallen closer to the coast, with the most rain falling in Brazoria County. The San Bernard River will crest about 2' above flood stage near Sweeny this weekend.
The heaviest storms should shift north and west this weekend. Heavy rain is possible in Dallas, Austin and San Antonio. Here in the Houston area, we expect more rain on Saturday, but a little less on Sunday. A few peeks of the sun are even possible! However, the rain that does develop will heavy.
Folks planning on attending the Freedom over Texas celebration on Sunday should expect the ground to be wet and muddy. There's only a 40% chance of dry weather Sunday afternoon but there should be fewer showers on MegaDoppler 13 late Sunday evening when the fireworks explode in the sky over downtown Houston.
Meantime in the tropics...
We're watching an area of storms in the eastern Gulf of Mexico. If a tropical cyclone develops it will not move toward Texas but could affect the oil spill south of Louisiana. North winds could actually move some of the oil away from the coast.
The European Model is also forecasting a new tropical system in the Bay of Campeche next week, very close to where Hurricane Alex developed. I mention this because the European did particularly well forecasting the development of Alex and the eventual landfall in northern Mexico.