The Knollwood plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Chance of showers
Showers likely; cooler
Chance of showers; warmer
Partly cloudy
Mostly cloudy
Partly cloudy
Partly cloudy
8.22 inches of rain fell in two days, the most for this week of the year since records began in 1897. The next wettest, 6.03 inches, fell in 1978.
Knollwood’s center stands about 830 ft above sea level. Within three miles the land runs from 660 ft to 870 ft, a difference of 210 ft: rolling country.
Under the town center the state geologic map shows Austin Chalk (marlstone, chalk), from the Late Cretaceous, 66 to 100 million years old.
The section below crosses 9 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 48×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Marlstone, chalk. Age: Late Cretaceous, 66 to 100 million years old. About 9 mi of the line.
Black-shale, siltstone. Age: Late Cretaceous, 66 to 100 million years old. About 6 mi of the line.
Sandstone-mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Limestone. Age: Early Cretaceous, 100 to 145 million years old. About 2 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Claystone. Age: Early Cretaceous, 100 to 145 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 3 smaller units along the line are not listed.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Knollwood reaches the Gulf of America by way of Post Oak Creek, Choctaw Creek, the Red River, the Atchafalaya and the Lower Atchafalaya: about 830 river miles.
660 miles of the trip are on the Red River.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Knollwood; river miles along the main stem, rounded.
Knollwood has a humid subtropical climate. Summer afternoons average 93° in July; winter nights fall to about 34° in January. About 44 inches of rain fall in a normal year.
On November 14 Knollwood normally reaches 64° and falls to 44°. The record high is 86°, in 1955; the record low 21°, in 1940. The most rain on this date, 7.93 in, fell in 1994.
Normals 1991–2020 and records since 1897 at Sherman, here. NOAA, through RCC-ACIS.
