The Allegheny 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.
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74° on Nov. 11, 2020, the hottest reading for this week of the year since 1964. Next is 70° in 1964.
Allegheny’s center stands about 1,780 ft above sea level. Within three miles the land runs from 1,710 ft to 2,080 ft, a difference of 370 ft: rolling country. The highest named summit within 15 miles is Ritchey Knob, about 2,880 ft, 14 miles south-southeast.
Under the town center the state geologic map shows Casselman Formation (shale, clastic), from the Carboniferous, 299 to 324 million years old.
The section below crosses 10 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 14×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Shale. Age: Carboniferous, 299 to 324 million years old. About 9 mi of the line.
Shale, clastic. Age: Carboniferous, 299 to 324 million years old. About 7 mi of the line.
Sandstone. Age: Carboniferous, 299 to 324 million years old. About 4 mi of the line.
Sandstone, siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 0.8 mi of the line.
Siltstone, shale. Age: Late Devonian, 359 to 384 million years old. About 0.7 mi of the line.
Sandstone. Age: Late Devonian, 359 to 384 million years old. About 0.7 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale. 4 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 Allegheny reaches Chesapeake Bay and the Atlantic Ocean by way of Beaverdam Run, Clearfield Creek, the West Branch Susquehanna and the Susquehanna: about 370 river miles.
Lake on the way: Lake Aldred.
170 miles of the trip are on the West Branch Susquehanna.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Allegheny; river miles along the main stem, rounded.
Allegheny has a warm-summer humid continental climate. Summer afternoons average 79° in July; winter nights fall to about 16° in January. A normal year brings about 80 inches of snow; with the rain, that comes to about 49 inches of water.
On November 14 Allegheny normally reaches 48° and falls to 29°. The record high is 69°, in 1994; the record low 5°, in 1986. The most rain on this date, 0.74 in, fell in 1993.
Normals 1991–2020 and records since 1964 at Ebensburg Sewage Plant, 8 miles southwest, 160 ft higher. NOAA, through RCC-ACIS.
