The Merrimac 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.
Partly cloudy
Partly cloudy; warmer
Mostly sunny; warmer
Sunny
Sunny
Mostly sunny
Mostly sunny
3.93 inches of rain fell in two days, the most for this week of the year since records began in 1893. The next wettest, 3.66 inches, fell in 2009.
Merrimac’s center stands about 2,140 ft above sea level. Within three miles the land runs from 1,580 ft to 2,410 ft, a difference of 830 ft: hilly country. The highest named summit within 15 miles is Bald Knob, about 4,350 ft, 12 miles north-northwest.
The section below crosses 11 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 13×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Sandstone. Age: Carboniferous, 324 to 359 million years old. About 5 mi of the line.
Limestone. Age: Cambrian to Ordovician, 445 to 542 million years old. About 3 mi of the line.
Shale, sandstone. Age: Devonian, 359 to 422 million years old. About 3 mi of the line.
Dolostone, limestone. Age: Cambrian, 487 to 542 million years old. About 3 mi of the line.
Shale, black-shale. Age: Devonian, 359 to 422 million years old. About 2 mi of the line.
Sandstone, limestone, shale. Age: Silurian to Devonian, 359 to 445 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. 5 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 Merrimac reaches the Gulf of America by way of Slate Branch, Stroubles Creek, the New River, the Kanawha, the Ohio and the Mississippi: about 1,920 river miles.
970 miles of the trip are on the Mississippi.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Merrimac; river miles along the main stem, rounded.
Merrimac has a warm-summer humid continental climate. Summer afternoons average 82° in July; winter nights fall to about 22° in January. A normal year brings about 25 inches of snow; with the rain, that comes to about 43 inches of water.
On November 14 Merrimac normally reaches 55° and falls to 31°. The record high is 73°, in 1958; the record low 9°, in 1986. The most rain on this date, 1.40 in, fell in 1972.
Normals 1991–2020 and records since 1893 from the Blacksburg Area threaded record (Blacksburg Nwso, here). NOAA, through RCC-ACIS.
