Widespread rains likely on Wednesday and Thursday

I hope everyone is enjoying the sunny start to 2019. I’m just jumping in here on New Year’s Day to note that the messy pattern on Wednesday and Thursday—before a front sweeps through, and clears out our weather for a beautiful weekend—is trending wetter.

In short, the front responsible for our clear skies today has essentially stalled offshore, and this will allow moisture to flow back toward the Texas coast at higher levels of the atmosphere. Meanwhile, a slow-moving upper-level low pressure system will approach the region from the west, arriving in time to set up a wet pattern on Wednesday and Thursday. Whereas this looked like a moderate, 1-inch rain storm yesterday, it now appears capable of producing widespread areas of 1 to 3 inches of rainfall, with higher isolated totals.

During summertime, such rainfall amounts would be of little concern. But now, in the middle of winter, with vegetation mostly dead or dormant and saturated soils, rainfall will not be readily absorbed, and will instead pond in yards as well as run into streets and bayous. We don’t anticipate too many problems, but there are some concerns about brief street flooding and area rivers. These waterways are falling from peaks on Sunday, but could rise again fairly quickly. According to Jeff Lindner of the Harris County Flood Control District, there is also concern for watersheds that respond like a river system: Cypress Creek, Little Cypress Creek, Willow Creek, Spring Creek, Cedar Bayou, and the creeks that drain into Addicks and Barker Reservoirs.

The rain potential begins to increase by Wednesday morning, and this mess should finally clear out by Thursday late morning, or afternoon. After that we can expect mostly sunny skies through the weekend—which still looks pretty spectacular for early January.