The Ivan 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
Mostly sunny
Mostly sunny
16° on Nov. 13, 2019, the coldest reading for this week of the year since 1911. Next is 20° in 1911.
Ivan’s center stands about 240 ft above sea level. Within three miles the land runs from 200 ft to 320 ft, a difference of 120 ft: gently rolling country.
Under the town center the state geologic map shows Claibourne Group (sand, clay), from the Middle Eocene, 38 to 48 million years old.
The section below crosses 4 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, clay. Age: Middle Eocene, 38 to 48 million years old. About 17 mi of the line.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 4 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 2 mi of the line.
Marl. Age: Late Eocene, 34 to 38 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.
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 Ivan reaches the Gulf of America by way of Dry Branch, Cooks Creek, Jug Creek, Fritz Creek, Hurricane Branch, Caney Creek, Wahl Branch, Wolf Branch, the Ouachita, the Black River, the Red River, the Atchafalaya and the Lower Atchafalaya: about 500 river miles.
230 miles of the trip are on the Ouachita.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Ivan; river miles along the main stem, rounded.
Ivan has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 31° in January. About 58 inches of rain fall in a normal year, with about 1 inch of snow.
On November 14 Ivan normally reaches 64° and falls to 40°. The record high is 86°, in 1955; the record low 16°, in 2019. The most rain on this date, 2.00 in, fell in 1915.
Normals 1991–2020 and records since 1911 at Fordyce, 6 miles south-southeast. NOAA, through RCC-ACIS.
