The Gretna 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
Mostly sunny
Mostly cloudy
Mostly sunny
Mostly sunny
Partly cloudy
Partly cloudy
86° on Nov. 12, 2020, the hottest reading for this week of the year since 1968. Next is 85° in 1986.
Gretna’s center stands about 250 ft above sea level. Within three miles the land runs from 230 ft to 330 ft, a difference of 100 ft: gently rolling country.
Under the town center the state geologic map shows Citronelle Formation (sand), from the Late Pliocene, 2.6 to 3.6 million years old.
The section below crosses 3 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.
Sand. Age: Late Pliocene, 2.6 to 3.6 million years old. About 20 mi of the line.
Clay, sand, gravel. Age: Tertiary Neogene, 2.6 to 23 million years old. About 3 mi of the line.
Sandstone, limestone. Age: Middle Miocene, 12 to 16 million years old. About 2 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 Gretna reaches the Gulf of America by way of Telogia Creek and the Ochlockonee: about 100 river miles.
55 miles of the trip are on Telogia Creek.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Gretna; river miles along the main stem, rounded.
Gretna has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 40° in January. About 60 inches of rain fall in a normal year.
On November 14 Gretna normally reaches 73° and falls to 47°. The record high is 81°, in 2005; the record low 27°, in 2011. The most rain on this date, 2.95 in, fell in 2008.
Normals 1991–2020 and records since 1968 at Quincy 3 SSW, 7 miles east-southeast. NOAA, through RCC-ACIS.
