A fast-evolving cluster of thunderstorms raced hundreds of miles from central Texas to the New Orleans area in a matter of hours on Thursday night. Wind gusts topping 80 mph downed trees and power lines and shattered windows. Especially hard-hit was the Houston area, where shards of glass littered parts of downtown and swarms of downed tree limbs blocked streets and sidewalks.
At least four deaths were attributable to the storms, including several from downed trees and limbs and one from a crane , said Houston Mayor Frank Whitmire in a Friday press conference as reported by the Associated Press.
Some parts of the Houston area may be without power for weeks, warned Harris County Judge Lina Hidalgo (the top official for the county, which includes Houston), at the press conference. The power outages will cause heat illness concerns this weekend, since heat indices will be in the 90s and many people will not have air conditioning.
Peak wind gusts from the storm complex include 78 mph at a mesonet station on Interstate 10 about 20 miles east of downtown Houston, 84 mph at the New Orleans International Airport, and 82 mph (twice) at New Orleans Lakefront Airport. Storm surveys will aim to determine whether there were any brief embedded tornadoes in the storm system. One tornado was reported near Convent, Louisiana, west of New Orleans, in the preliminary storm reports compiled by the NWS/NOAA Storm Prediction Center for Thursday and early Friday. The list included more than 100 reports of severe wind gusts (at least 50 knots or 58 mph).
Derecho or not, a hugely destructive system
The storm system had some of the earmarks of a derecho, a fast-moving corridor of intense thunderstorm winds. However, it’s not yet clear whether this system will meet the most recent derecho definition, updated in 2002. Along with widely dispersed gusts above 65 knots (74 mph), severe wind gusts must have occurred along most of the corridor for it to qualify as a derecho.
Regardless of definitions, Thursday’s powerhouse brought back memories of the storm system on August 10-11, 2020, that spawned a highly destructive derecho centered in Iowa and wreaked some $13.3 billion in damage (USD 2024).
“This absolutely has all the makings of damage costs surpassing $1 billion,” said Steve Bowen, chief science officer at Gallagher Re, in a direct message. “The expanse of damage, heavily driven by wind, to both residential and commercial structures in Texas will drive the losses.”
As is often the case with derecho-like events, severe weather was well predicted ahead of time – the potential for a late-day swath of damaging wind gusts from central toward southeast Texas was noted by the NWS/NOAA Storm Prediction Center in its 1 a.m. CDT Thursday morning outlook – but whether a truly high-end event would emerge wasn’t obvious till the storm complex itself took shape.
The complex raced east-southeast along a preexisting stalled frontal boundary near the northwest Gulf Coast, reinforced by outflow from earlier thunderstorms. A surge of moisture at near-record levels for mid-May gave the storms added juice, and a cold upper low stretched from west to east across Texas, boosting instability further and providing jet-stream energy.
High rises and high window risks
When it comes to shattered high-rise windows, this wasn’t Houston’s first rodeo. Hurricane Alicia damaged as many as half of lower-level windows in Houston skyscrapers in August 1983, and window blow-outs were again common during Hurricane Ike in September 2008. Other major window-busting U.S. hurricanes include Hurricane Laura (August 2020, Lake Charles, Louisiana) and Hurricane Wilma (October 2005, South Florida). Last October, Hurricane Otis ravaged many high-rise exteriors in Acapulco.
Houston’s high-rise damage for Thursday night was dramatic in spots, but it appears to be more patchy than that from Alicia and Ike. “The broken glass on high rises seems to be concentrated in a few blocks of Louisiana Street. I wouldn’t be surprised if it turns out a tornado went up the street here,” said local author Christof Spieler in a Twitter/X post. He added: “Across most of the area the only visible damage is tree limbs down everywhere.”
An EF3 tornado that smacked downtown Fort Worth on March 28, 2000, left one of the city’s tallest buildings in tatters. Mold damage and other woes soon beset the structure, and it was nearly condemned and demolished before being rehabilitated and enlarged into an upscale condo complex.
Window damage has been a major issue even in San Francisco, where broken windows pelted streets with glass and unnerved pedestrians after winter storms brought wind gusts to 70 mph in March 2023. A subsequent report commissioned by the city found that heat, hardware issues, and/or glass contamination had left many of the broken windows vulnerable before the winds struck.
Matt Lanza, managing editor of Space City Weather in Houston, captured the city’s surprise in his Friday analysis, “Houston, what the heck happened on Thursday?” Lanza noted that the serious threat of flooding rains (an unusual high risk for excessive rain was in place just north of Houston) took initial precedence among local weather-watchers until a tornado watch came out and the storm complex took shape. He stressed that the brief but frightening windstorm should serve as a reminder to locals that hurricane season is nearly upon them:
We know a lot about flooding. Most of us know about surge. Very few knew about wind and what it’s really like. Many do now. Use this experience to inform your preparation for hurricane season just in case. Houston has been through an absolute meat grinder of weather disasters in the last 10 years. Candidly, it sucks, but we should know enough now to prepare for the next one.
Bowen also sees the Thursday storm as a wake-up call:
This is a reminder that Texas has a lot of work to do regarding building codes. It remains far behind several other states, notably Florida, when it comes to preparedness in mandating higher quality construction. This does not suggest that better codes would have fully reduced the damage from yesterday’s storms, but it likely would have helped mitigate against some of it.
In the latest “Ratings the States” report on building code strength, issued on April 23 by the International Institute for Business and Home Safety, Texas ranked second-last, ahead of only Alabama, among the 17 states on the U.S. Gulf and Atlantic coasts. The report is updated every three years. Virginia and Florida have traded places at the top of the list in each of the last three reports.
“Eight of 18 states have lower scores than they did in 2021,” said the institute’s Ian Giammanco in a news release. “By not advancing efforts to increase resilience, these states risk falling behind and leaving their citizens and communities vulnerable to storms.”
The national crisis in home insurance is also hitting Texas increasingly hard. In 2023, the state’s home insurance rates jumped 23.3%, more than double the national average and the most of any state, according to a report from S&P Global.
Jeff Masters contributed to this post.