The Portland 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
Partly cloudy
Mostly sunny
Partly cloudy
Mostly sunny
Mostly sunny
Mostly sunny
6.90 inches of rain fell in two days, the most for this week of the year since records began in 1909. The next wettest, 4.65 inches, fell in 1957.
Portland’s center stands about 140 ft above sea level. Within three miles the land runs from 110 ft to 150 ft, a difference of 40 ft: nearly flat ground.
Under the town center the state geologic map shows Alluvium - Alluvial deposits of local streams or of overbank flow of major streams (coarse-detrital, fine-detrital), from the Holocene, less than 12,000 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.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 15 mi of the line.
Coarse-detrital, fine-detrital. Age: Pleistocene, less than 2.6 million years old. About 6 mi of the line.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
Coarse-detrital, fine-detrital. Age: Holocene, less than 12,000 years old. About 0.3 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 Portland reaches the Gulf of America by way of Dry Bayou, Big Bayou, the Boeuf, the Ouachita, the Black River, the Red River, the Atchafalaya and the Lower Atchafalaya: about 390 river miles.
140 miles of the trip are on the Boeuf.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Portland; river miles along the main stem, rounded.
Portland has a humid subtropical climate. Summer afternoons average 91° in July; winter nights fall to about 32° in January. About 56 inches of rain fall in a normal year, with about 1 inch of snow.
On November 14 Portland normally reaches 65° and falls to 42°. The record high is 83°, in 1999; the record low 18°, in 2019. The most rain on this date, 2.75 in, fell in 1993.
Normals 1991–2020 and records since 1909 at Portland, here. NOAA, through RCC-ACIS.
