Sluggish Imelda threatens floods
First named storm to hit region since Harvey brings heavy rains, school closures
The first named storm to hit Houston since Hurricane Harvey is expected to soak the area until Thursday with waves of heavy rainfall, threatening to swell bayous, flood low-lying streets and tie up the morning commute as tropical depression Imelda crawls north through southeast Texas.
The slow-moving system formed Tuesday afternoon over the Gulf of Mexico and at 1 p.m. made landfall in Freeport with maximum winds of 40 mph.
The Houston area experienced the first of two periods of concentrated rain Tuesday night into Wednesday morning, and a second is predicted Wednesday night into Thursday morning, forecasters say. Widespread rainfall estimates of 4 to 7 inches are expected through Thursday, with totals possibly reaching up to 12 inches in some isolated areas, according to Harris County Flood Control District Meteorologist Jeff Lindner.
He said there is still uncertainty about the exact rainfall levels and areas that will be most impacted. However, he noted that conditions are not comparable to Harvey. The storm initially was upgraded to a tropical system but later Tuesday night downgraded to a tropical depression.
“Yeah, it’s the first named storm since Harvey, but the upgrade (Tuesday) didn’t necessarily change the forecast a whole lot,” Lindner told the Houston Chronicle. “The good news is, we’re going into this event dry, so all of our bayous and creeks are flowing below normal. We have a lot of capacity in our channel and detention basins, and even the soil itself. That is going to help us.”
Lindner added that people need to pay close attention to the forecast, even with dry conditions. The forecast estimates about 1 to 2 inches of rain per hour during the storm. If rainfall levels exceed those
numbers, chances of excessive flooding increase, he said.
A number of school districts and colleges canceled Wednesday classes. As of Tuesday night, Houston ISD canceled only afterschool activities.
County officials are keeping a close watch over bayous and creeks, and the Harris County Sheriff’s Office on Tuesday prepared a number boats and highwater vehicles throughout their five patrol districts.
The National Weather Service had tracked the storm since Saturday, when it was a disorganized area of low pressure in the eastern Gulf. On Tuesday, as the system approached Freeport, the National Hurricane Center declared the storm a tropical depression. It was upgraded to a tropical storm about 12:45 p.m. and downgraded back to a depression by 7 p.m.
A flash flood watch remained in effect Tuesday night for Harris, Brazoria, Galveston, Chambers, Matagorda, Fort Bend and Liberty counties.
“If you start to see that bayou and creek near your house getting up to some higher levels, that’s when you need to start preparing to take action,” Lindner said. “Get your valuables up off the floor. … If we do start to see some street flooding, and water goes into your home, then stay where you’re at.”
As of 9 p.m. Tuesday, portions of southeastern Harris County had already seen close to 6 inches of rain over 24 hours, according to the Harris County Flood Warning System.
Most channels remained within their banks, according to the Harris County Flood Control District. Armand Bayou and Clear Creek were elevated and on Wednesday will be monitored. Turkey Creek at FM 1959 Tuesday night was nearing the top of its banks, the flood control district stated.
The eastern and central portions of Harris County will likely get the worst of the wet weather before it moves north, Lindner said. On Wednesday morning, rainfall mainly will impact the U.S. 59 corridor from Victoria to Houston to Livingston, according to the National Weather Service.
The storm is moving about 7 mph and could affect the Houston area through Thursday evening. The forecast shows the storm moving north through Huntsville toward Tyler over the next few days. The National Hurricane Center forecast also shows the system affecting portions of southwestern Louisiana.
The tropical depression is forecast to dissipate within three days, according to the hurricane center.
“This event is more like a halfmarathon, not a sprint,” according to the National Weather Service.
The Harris County Emergency Operations Center activated Tuesday afternoon at Level III, which indicates an increased risk of a threat. According to the Harris County Regional Joint Information Center, that classification prompts surrounding agencies in Harris County to monitor the storm from the operations center, located on the third floor of the Houston TranStar building on Katy Road.
The most intense rain is expected during the overnight hours — a pattern among large tropical systems, Lindner said. He said previous storms that hit Houston, including Tropical Storm Frances, Tropical Storm Allison and Hurricane Harvey, had similar characteristics.
“The daytime heating breaks up (the storm’s) circulation,” he said, adding that drivers should avoid parking their cars in the street overnight.
As Imelda continues farther inland, another major storm threatens to make landfall, possibly in Bermuda. Hurricane Humberto, a Category 3 with winds of 115 mph, is expected to bring hurricane conditions to Bermuda Wednesday night and Thursday morning.
That storm also could cause life-threatening surf and rip-current conditions in the southeastern coast of the United States from east-central Florida to North Carolina, the hurricane center reported.