Heavy Rains Could Bring Flash and Riverine Flooding This Week
5/17/26 – According to Jeff Lindner, Harris County’s meteorologist, a wet and stormy period mid to late week could bring heavy rainfall, severe thunderstorms, flash flooding, and riverine flooding. The wet and stormy pattern will likely last through the Memorial Day weekend.
Weather Pattern
A slow-moving, upper-level trough will blanket the southwest through much of this week into next weekend while both surface Gulf moisture and high-level Pacific moisture stream into the area.
Additionally, a slow-moving frontal boundary will sag into the area mid to late week. Lindner says, “This is a classic mid to late May stormy pattern for Texas.”
The overall pattern looks stormy as early as late Tuesday. Incoming upper-level disturbances will be hard to time. So, while rain chances will remain high into next weekend, there will be periods of stormy weather followed by breaks.
Complexes of thunderstorms from the west and northwest will move into the area from time to time with the potential for heavy rainfall and severe weather until late week. When the slow-moving/stalled frontal boundary is nearby or overhead, it will help promote more sustained thunderstorm formation and potential cell training.
Rainfall Predictions
Nearly all of the major global weather models show heavy to excessive rainfall potential. However, it will be difficult to predict precisely where storms will train and how long breaks will be between rounds.
These are all details that will be worked out in the next several days as forecast confidence increases.
Expect widespread rainfall amounts of 2-5 inches from Wednesday through Sunday with isolated totals much higher in areas of cell training of slow moving storms. These totals may increase some over the next few days.
Initially, rainfall will soak into the ground. But repeated rounds of rain and training storms could quickly result in higher runoff rates and flash flooding.
Additionally, the large footprint of the forecasted rainfall will yield rises on area rivers systems. And it is possible that some rivers could approach or exceed flood stage by next weekend.
At this time, Pivotal Weather predicts 4.3 inches for Harris County, 5.1 for Montgomery County, and 6.1 for Walker County. The headwaters for Lake Conroe lie in Walker County and heavy rains there in the past have led to the SJRA opening its flood gates.
For instance, in May 2024, rainfall north of Harris County exceeded 10.0-15.0 inches in many locations. And it exceeded 15.0-20.0 inches on the headwaters of the East Fork and north of Lake Conroe on the West Fork.
Severe Threat
A low daily threat of severe weather (wind and hail) from late Tuesday onward exists. But this threat is conditional on several factors that are hard to determine at this time. Keep your eye on the sky and weather forecasts in coming days. The wet pattern may even linger into next week.
Posted by Bob Rehak on 5/17/2026
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