Residents in Houston’s southeastern suburbs collected the broken pieces Wednesday after a powerful tornado ripped through the neighborhood earlier in the afternoon. Meanwhile, severe weather danger shifted southeast, with an ongoing risk of strong to damaging winds and isolated tornadoes in southern Virginia, the Carolinas and Georgia.
Tuesday’s conditions favored dangerous thunderstorms, but only along the immediate Gulf Coast.
A tornado struck Pearland and Pasadena, Texas, before strengthening as it moved northeast, prompting the National Weather Service’s Houston-Galveston office to issue its first “tornado emergency.” Meteorologists warned that the tornado, which was already devastating structures, was “large and extremely dangerous.”
The Weather Service has confirmed at least EF2 damage — which corresponds to winds in the range of 111 to 135 mph or more — though survey teams were still combing the damage trail for clues to confirm the tornado’s intensity.
The storm system also brought heavy downpours. Houston picked up 4.04 inches of rain, with more than 3.5 inches falling in just two hours. It is the second wettest January day since weather records began at Houston’s George Bush Intercontinental Airport, where records date back to 1969.
Meanwhile, tornado watches were issued in the Florida Panhandle with the possibility of expanding further east. Severe weather was expected to hit the Interstate 95 corridor later in the evening, with storms pushing offshore before midnight.
It was an exceptional January for severe weather. A staggering 159 preliminary reports of tornadoes have been received with almost a week remaining this month – 16 were from Tuesday’s storm swarm. A typical January features an average of three dozen twisters across the Lower 48.
On Tuesday, an “elevated” Level 3 (out of 5) severe weather risk stretched from the south of Texas’ Matagorda Peninsula to the Mississippi Delta and Florida Panhandle. The weather service warned of a “conditional” risk of strong tornadoes. While there was little instability or “juice” for storms, this limited lift was offset by robust shear – a change in wind speed and/or direction with altitude.
Thunderstorms were not expected to bloom to particularly high altitudes, but any multi-layered clouds were encouraged to rotate. This was particularly true along the warm front itself, where storms could pick up more concentrated flow vortices, or horizontal vortices, which were then flipped onto a vertical approach.
That gave a little boost to a thunderstorm cell south of Houston in the afternoon. A rotational kink developed near Pearland at about 3:15 p.m., which quickly spawned a tornado. Then this circulation turned northeast as a second gyre area developed a few miles north of it. At least two rotation areas were present at the same time, and it is possible that two tornadoes were briefly on the ground at the same time.
It then appears that the vorticity or spin of both circulations merged east-northeast of Pearland, somewhere near the intersection of Interstate 45 and the Sam Houston Turnpike.
That then developed into a severe tornado, prompting the Weather Service to declare a severe tornado emergency for locations along Route 330 between Baytown and Interstate 10 near McNair.
It was the first time the Houston Weather Service had done so. Debris was hurled more than 10,000 feet into the air.
“Returned from a week’s vacation to call my first and first tornado emergency in the office,” tweeted Jimmy Fowler, the Houston Weather Service’s forecaster on duty during the storms. “Kind of blurry and maybe blinked a total of 8 times throughout the shift.”
A few more tornadoes whipped up in the Golden Triangle along the Texas-Louisiana border.