The McNab 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.
Sunny
Chance of showers
Chance of showers; warmer
Partly cloudy
Mostly sunny
Partly cloudy
Mostly sunny
4.82 inches of rain fell in two days, the most for this week of the year since records began in 1893. The next wettest, 3.95 inches, fell in 1985.
McNab’s center stands about 330 ft above sea level. Within three miles the land runs from 250 ft to 440 ft, a difference of 190 ft: gently rolling country.
Under the town center the state geologic map shows Arkadelphia Marl (marlstone, mudstone), from the Late Cretaceous, 66 to 100 million years old.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 64×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 9 mi of the line.
Sandstone. Age: Late Cretaceous, 66 to 100 million years old. About 8 mi of the line.
Marlstone, mudstone. Age: Late Cretaceous, 66 to 100 million years old. About 3 mi of the line.
Limestone. Age: Late Cretaceous, 66 to 100 million years old. About 2 mi of the line.
Marlstone. Age: Late Cretaceous, 66 to 100 million years old. About 1 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 0.6 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
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 McNab reaches the Gulf of America by way of Bridge Creek, Bois D'Arc Creek, the Red River, the Atchafalaya and the Lower Atchafalaya: about 530 river miles.
380 miles of the trip are on the Red River.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of McNab; river miles along the main stem, rounded.
McNab has a humid subtropical climate. Summer afternoons average 93° in July; winter nights fall to about 32° in January. About 53 inches of rain fall in a normal year, with about 2 inches of snow.
On November 14 McNab normally reaches 64° and falls to 41°. The record high is 86°, in 1955; the record low 18°, in 2019. The most rain on this date, 3.25 in, fell in 1958.
Normals 1991–2020 and records since 1893 at Ashdown 4 SSE, 16 miles west. NOAA, through RCC-ACIS.
