The National Weather Service has extended a Flood Watch through Thursday morning for all of Galveston County as forecasters warn that multiple rounds of heavy rainfall could produce life-threatening flash flooding across the region.
The watch covers all of Galveston County, including Galveston Island, Bolivar Peninsula, Texas City, League City, Dickinson, Friendswood and La Marque. Forecasters are predicting widespread rainfall totals of 4 to 7 inches through early Thursday, with isolated areas potentially receiving 10 to 15 inches.
"There is an increased danger to lives and property due to flash flooding," the National Weather Service said Monday. "Flash flooding is likely and considerable flash flooding is possible."
The flood threat is being driven by a combination of a stalled frontal boundary and a tropical disturbance expected to move into the northwestern Gulf later this week. While tropical development remains uncertain, the National Hurricane Center said the system has a 40 percent chance of becoming a tropical depression or short-lived tropical storm within the next 48 hours and a 50 percent chance within the next seven days.
Regardless of whether the system becomes a named storm, forecasters say the primary threat to Galveston County will be prolonged periods of heavy rainfall capable of producing widespread flash, urban and river flooding. Gusty winds and minor coastal flooding also are possible along the upper Texas coast.
Local emergency officials are urging residents to prepare now for the possibility of significant flooding.
Joe Tumbleson, emergency manager for the City of Texas City, said the region is facing two distinct weather threats this week. The first is a weak frontal boundary expected to bring showers, thunderstorms and localized flooding through Tuesday. The second, and potentially more dangerous threat, is a slow-moving tropical disturbance forecast to affect the area beginning Wednesday and possibly lingering through Friday.
"This system will surge deep tropical moisture into the area, creating conditions capable of extremely high rainfall rates and serious, potentially life-threatening flooding," Tumbleson said.
Forecasters cannot yet determine where the heaviest rainfall bands will set up, meaning communities throughout Galveston County remain at risk. Tumbleson noted that rainfall rates of 2 to 5 inches per hour are possible during the most intense storms.
In Galveston, city officials said they are closely monitoring the evolving forecast and remain in communication with the National Weather Service and regional emergency management partners.
The city's Office of Emergency Management has been tracking the system since forecasts began indicating the potential for significant rainfall along the upper Texas coast, according to Public Information Officer Marissa Barnett.
Residents should prepare for street flooding and minor coastal flooding, particularly during periods when heavy rainfall coincides with high tides, Barnett said. She encouraged residents to secure outdoor items and clear debris that could obstruct storm drains and worsen localized flooding.
The heaviest rainfall is currently expected Wednesday afternoon through Thursday morning, Barnett said. City crews will continue monitoring conditions throughout the week and provide updates as forecasts are refined and additional weather alerts are issued.
Dickinson officials are closely monitoring weather conditions this week as heavy rainfall and possible tropical development threaten the region. City manager Chaise Cary said staff have reviewed preparedness measures and are actively monitoring drainage infrastructure and response resources while coordinating with the National Weather Service and regional emergency management partners.
Officials are encouraging residents to monitor forecasts closely, sign up for emergency alerts, review flood safety plans and avoid driving through flooded roadways. Additional flood warnings, as well as tropical storm watches or warnings, could be issued later this week as conditions develop.
Corey Greineisen: corey.greineisen@galvnews.com; 409-683-5226
