Today, Jeff Lindner, Harris County’s meteorologist issued a report on last weekend’s (1/8/22 – 1/9/22) storm. One of the more interesting findings: According to the National Weather Service, the Kingwood tornado was the widest, strongest and longest of five that touched down in Harris County. See below.
Wealth of Detail Beyond ReduceFlooding Reports
Lindner’s report confirms my “after-action” reports, but adds a wealth of details.
- Rainfall rates of 2-3 inches/hour were common in the slow-moving training thunderstorms.
- That led to rapid and significant street flooding, and rises on area creeks and bayous.
- The highest measured discharge (streamflow) rate was in Greens Bayou at Mount Houston Parkway – 7,067 cubic feet per second.
Lindner found that certain areas experienced 2- to 10-year rains based on Atlas-14 exceedance probabilities. Based on 1- to 3-hour rainfall rates, those included middle Buffalo Bayou, Luce Bayou, middle and upper Halls Bayou, middle Greens Bayou, middle and lower White Oak Bayou, and the lower portion of the East Fork of the San Jacinto River. However, based on 12- to 24-hour rates, all impacted watersheds experience 2- to 5-year rains.
Because the storms trained perpendicular to the direction of most bayous, the rainfall within their watersheds varied greatly. For instance:
- Greens Bayou received on 0.9 inches at Mount Houston Parkway, but 6.2 inches at US59.
- Buffalo Bayou received 5.2 inches in places and 0.2 in others – a 26X difference.
Like all of the work that comes out of Lindner’s department, the documentation is meticulous.
House Flooding Estimates
Contrary to previous reports, some house flooding did occur. It happened along Brickhouse Gully on the west side of Bingle Rd. Approximately 6-8 structures experienced flooding to depths of 4.0-6.0 inches.
Says Lindner, “Other isolated structures may have flooded in portions of Spring Branch due to the intense rainfall rates overwhelming street and local drainage systems. A few houses also flooded along Valley Stream downstream (east) of I-45 along Halls Bayou.”
Unfortunately, Lindner doesn’t offer much more information about the Kingwood tornado at this time. Nor does he cover flooding in surrounding areas, such as Liberty County. However, the storm did set off a number of alarms.
The storm triggered 26 rainfall alarms when gages received more than an inch of rain in 15-minutes.
Rising water triggered 14 flood warnings when streams reached 3 feet below bankfull.
For detailed maps, rainfall rates, and exceedance statistics at dozens of locations, see Lindner’s full report. Note: on major storms, Lindner often issues an immediate report and a final report several weeks later. This report falls into the “immediate” category. For future reference, you can also find this report under the Major Storms tab on the reports page.
Posted by Bob Rehak on 1/13/22
1598 Days since Hurricane Harvey