The Roanoke 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.
6.45 inches of rain fell in two days, the most for this week of the year since records began in 1897. The next wettest, 5.68 inches, fell in 1961.
Roanoke’s center stands about 30 ft above sea level. Within three miles the land runs from 10 ft to 30 ft, a difference of 20 ft: nearly flat ground.
Under the town center the state geologic map shows Prairie Terraces (clay, silt, sand), from the Pleistocene, less than 2.6 million years old.
The section below crosses 2 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.
Clay, silt, sand. Age: Pleistocene, less than 2.6 million years old. About 23 mi of the line.
Clay. Age: Holocene, less than 12,000 years old. About 0.4 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 Roanoke reaches the Gulf of America by way of the West Bayou Grand Marais, the Bayou Chene, the Bayou Lacassine and the Mermentau: about 75 river miles.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Roanoke; river miles along the main stem, rounded.
Roanoke has a humid subtropical climate. Summer afternoons average 91° in August; winter nights fall to about 42° in January. About 64 inches of rain fall in a normal year.
On November 14 Roanoke normally reaches 71° and falls to 49°. The record high is 86°, in 1951; the record low 24°, in 2019. The most rain on this date, 2.02 in, fell in 1970.
Normals 1991–2020 and records since 1897 at Jennings, 6 miles east-southeast. NOAA, through RCC-ACIS.