Weather in Houston: the probability of storms will rise to 50% mainly after 2 p.m. Some areas may receive locally heavy rain and frequent lightning.
Houston will have a 50% chance of rain and thunderstorms during the afternoon of Thursday, August 27, after several days with temperatures near or above 100 °F in parts of the region.
The activity could begin in isolated fashion during the early hours of the day, but the greatest coverage is expected after 2 p.m. Thunderstorms could continue through the afternoon and into the early part of the night, with possible locally heavy rain, frequent lightning, and gusty winds.
The city will reach a high near 97 °F, equivalent to 36 °C. Humidity could still raise the heat index to 107 °F (about 42 °C) before clouds and rain increase.
The greatest chance of storms will begin after 2 p.m.
The Houston–Galveston office of the National Weather Service (NWS) estimates regional rain coverage of 30% to 50% for Thursday. The pinpoint forecast for downtown Houston places the probability at 50%, mainly during the afternoon.
Some isolated showers could move in from the north during the overnight hours or the early morning. That activity would have lower coverage, so not all parts of Houston and Harris County will receive rain during the morning commute.
The broader development will depend on daytime heating and the passage of weak disturbances over Southeast Texas. Rain can form rapidly in scattered areas, with varying conditions between the northern part of Harris County, downtown Houston, and communities near the coast.
Heavy rain and lightning will be the main hazards
The NWS does not anticipate a widespread severe thunderstorm outbreak, but warns that any storm can intensify and produce localized heavy rainfall, frequent lightning, and gusty winds.
The heaviest rain could temporarily reduce visibility and cause delays during the afternoon rush. The activity could continue until around 10 p.m., followed by a lower chance of rain before midnight.
As of the 11:50 p.m. update on Wednesday, a general flood watch was not in effect for Houston. Conditions could change if storms produce rapid accumulations on low-lying streets or areas with slow drainage.
The NWS states that, when thunder is heard, people outdoors should move to a sturdy building or a vehicle with a hard roof. Lightning can strike areas well away from the core of the rain.
Houston will reach 97 °F before the arrival of the rain
The increase in clouds and storms will slightly lower the temperature from the heat of the last few days, when parts of the metro area reached between 100 and 103 °F.
The change will not eliminate the heat risk. Houston could still record a heat index of up to 107 °F during the hours before the rain, while northern and interior parts of the region may approach 100 °F again.
The new chance of storms comes after one of the hottest weeks of the summer. Houston had maintained temperatures around 100 °F and heat indices above 105 °F for several days.
Friday will maintain a 40% chance of rain
The scattered thunderstorms will continue Friday, with a 40% probability mainly between 1 p.m. and 4 p.m. Downtown Houston will reach a high near 93 °F and a heat index of up to 104 °F.
Saturday and Sunday will return to mostly sunny conditions, with highs near 93 °F. There appear to be no significant chances of rain for the weekend in the current forecast.
The National Weather Service’s updated forecast for Houston will show any changes in timing, temperatures, or thunderstorm chances.
