The Jemison 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.
4.60 inches of rain fell in two days, the most for this week of the year since records began in 1957. The next wettest, 3.35 inches, fell in 2018.
Jemison’s center stands about 720 ft above sea level. Within three miles the land runs from 600 ft to 780 ft, a difference of 180 ft: gently rolling country.
Under the town center the state geologic map shows Tuscaloosa Group; Coker Formation (sand, clay), from the Cretaceous, 66 to 145 million years old.
The section below crosses 8 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.
Sand, clay. Age: Cretaceous, 66 to 145 million years old. About 10 mi of the line.
Slate, metasiltstone. Age: Precambrian to Cambrian. About 3 mi of the line.
Sand. Age: Holocene, less than 12,000 years old. About 3 mi of the line.
Metasiltstone. Age: Precambrian to Cambrian. About 3 mi of the line.
Metasiltstone, slate, quartzite. Age: Precambrian to Cambrian. About 2 mi of the line.
Greenstone, phyllite. Age: Paleozoic, 252 to 542 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. 2 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 Jemison reaches Mobile Bay and the Gulf of America by way of Gale Creek, Mulberry Creek, the Alabama and the Mobile: about 330 river miles.
230 miles of the trip are on the Alabama.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Jemison; river miles along the main stem, rounded.
Jemison has a humid subtropical climate. Summer afternoons average 90° in July; winter nights fall to about 33° in January. About 56 inches of rain fall in a normal year.
On November 14 Jemison normally reaches 66° and falls to 41°. The record high is 78°, in 2005; the record low 25°, in 2014. The most rain on this date, 1.62 in, fell in 1957.
Normals 1991–2020 and records since 1957 at Thorsby Experiment Station, 5 miles east-southeast. NOAA, through RCC-ACIS.