Weather Impact Alert: Heavy rain and strong storms trigger flash flood warnings in the Houston area

HOUSTON — Thursday will bring another day with widespread showers and thunderstorms. Rain chances ramp up quickly through the early morning hours and continue through noon. We could see lingering showers through the afternoon. 

• A Flash Flood Warning was issued for central Matagorda County until 11 a.m. At 6:59 a.m., Doppler radar and automated rain gauges indicated thunderstorms produced heavy rain across the warned area. Between 2.5 and 5 inches of rain have fallen. Though this initial round of heavy rain has moved off, more rain is incoming and is expected to begin in the next hour or two. Flash flooding is ongoing or expected to begin shortly.
• A Flood Watch is in effect through Thursday evening for the Houston metro and surrounding coastal and inland areas, including Galveston, Fort Bend, Wharton, and Jackson counties. The next round of storms is expected early Thursday morning, with potential for several inches of rain in a short time, especially where storms train or regenerate. Forecast models have shifted the heaviest rain southward, prompting an expanded watch area due to the evolving flood threat.

Thunderstorms have triggered a ground stop for all departures headed to Houston’s William P. Hobby Airport (HOU). The stop is in effect from 7:11 a.m. to at least 9 a.m., and impacts flights departing from multiple regional air traffic centers across the southern U.S.

• No inbound departures to HOU are being allowed during the alert window
• Medium chance (30–60%) of the stop being extended, depending on weather conditions

If you’re flying today, expect significant delays at Bush Intercontinental (IAH) due to thunderstorms. A Ground Delay is in effect, with an average delay of 96 minutes for inbound flights.

• Affects all domestic departures to IAH across the contiguous U.S.
• Travelers should check their airline’s app for updated departure and arrival times.
• Flights from major departure control centers nationwide — including Atlanta, Chicago, New York, Denver, and Los Angeles — are impacted.

The KHOU 11 Weather Team has issued a Weather Impact Alert through 4 p.m. Thursday due to multiple severe threats moving across Southeast Texas.

• Tornadoes are possible, especially in embedded cells within the morning to midday line of storms.
• Damaging straight-line winds could gust up to 60 mph across much of the area.
• Hail is possible closer to the coast, where storm cells have more energy to work with.

Stay weather-aware and be prepared to take shelter if warnings are issued.

A Level 1 out of 5 (Marginal Risk) has been issued for much of Southeast Texas, including Houston, Sugar Land, Tomball, Conroe, Liberty, and El Campo. This means there’s an elevated risk for damaging wind gusts, heavy rain, and dangerous lightning. 

Threats include:

• Damaging wind gusts
• Heavy downpours leading to street flooding

A moderate flood risk (Level 3 of 4) is in place for much of Southeast Texas today, including Houston, Galveston, Sugar Land, Conroe, Bay City, and Victoria. This means multiple rounds of rain could lead to widespread street flooding, especially in low-lying or poorly draining areas.

• Areas like El Campo, Angleton, Liberty, and Columbus are also firmly in the red zone.
• Brenham, Huntsville, and Livingston are near the northern edge of the risk area, while Austin and parts of East Texas are in the lower “slight” or “marginal” categories.

If you’re in the red zone, plan your travel carefully and expect water over roads in flood-prone spots.

The storms will move in early Thursday morning and linger through midday:

• 4:30 a.m. – Storms enter western counties (near Brenham, Bryan, Columbus)
• 7 a.m. – Line reaches downtown Houston
• 9–10 a.m. – Heaviest rain moves through the area
• By 1 p.m. – Storms push toward the coast and into far eastern counties
• After 3 p.m. – Conditions begin to settle down

Storms may arrive in one main round, but lingering showers are possible throughout the day.

• Entire Houston metro is under a Level 2 risk for severe storms.
• Northwest of Houston (e.g., Wharton, Columbus, north of Katy): May see the first signs of morning activity.
• South and coastal areas (e.g., Galveston, Pearland): Could see evening storms as activity shifts southward.

• Delay your commute or morning errands if possible. Roads may be waterlogged and dangerous by sunrise.
• Drive slowly and avoid flooded streets.
• Charge your devices Wednesday night in case of power outages due to high winds.
• Monitor alerts: Watches or warnings may be issued overnight or early Thursday.

• Friday: 60% chance of more rain and street flooding
• Weekend: 50/50 shot at scattered thunderstorms for both Saturday and Father’s Day
• Next week: Daily chances for pop-up showers and storms continue

Counties we serve:

Harris County (including Houston, Pasadena, Baytown), Fort Bend County (Richmond, Sugar Land, Missouri City), Montgomery County (Conroe, The Woodlands), Brazoria County (Angleton, Pearland, Alvin, Lake Jackson), Galveston County (Galveston, League City, Texas City), Liberty County (Liberty, Cleveland, Dayton), Walker County (Huntsville, New Waverly), Waller County (Hempstead, Prairie View, Waller), Polk County (Livingston, Corrigan), Chambers County (Anahuac, Mont Belvieu, Winnie), Wharton County (Wharton, El Campo), Washington County (Brenham), Matagorda County (Bay City, Palacios), Grimes County (Anderson, Navasota), Austin County (Bellville, Sealy), Colorado County (Columbus, Eagle Lake, Weimar), Trinity County (Groveton, Trinity).