The Bryn Mawr-Skyway 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.
Showers likely
Showers likely
Chance of showers
Mostly sunny
Mostly cloudy
Partly cloudy
Partly cloudy
3.80 inches of rain fell in two days, the most for this week of the year since records began in 1945. The next wettest, 3.18 inches, fell in 2015.
Bryn Mawr-Skyway’s center stands about 390 ft above sea level. Within three miles the land runs from 10 ft to 430 ft, a difference of 420 ft: hilly country. The highest named summit within 15 miles is Tiger Mountain, about 3,000 ft, 14 miles east.
The section below crosses 6 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 9×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Andesite, basaltic-andesite. Age: Late Eocene, 34 to 38 million years old. About 5 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 5 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 4 mi of the line.
Fine-detrital, coarse-detrital. Age: Pleistocene, less than 2.6 million years old. About 3 mi of the line.
Silt, sand. Age: Holocene, less than 12,000 years old. About 2 mi of the line.
Fine-detrital, coarse-detrital. Age: Late Pliocene to Pleistocene, less than 3.6 million years old. About 1.0 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 Bryn Mawr-Skyway reaches Puget Sound and the Pacific Ocean by way of Lake Washington: about 19 river miles.
Lake on the way: Lake Washington.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Bryn Mawr-Skyway; river miles along the main stem, rounded.
Bryn Mawr-Skyway has a warm-summer Mediterranean climate. Summer afternoons average 78° in August; winter nights fall to about 37° in December. A normal year brings about 6 inches of snow; with the rain, that comes to about 39 inches of water.
On November 14 Bryn Mawr-Skyway normally reaches 52° and falls to 41°. The record high is 65°, in 1995; the record low 9°, in 1955. The most rain on this date, 2.61 in, fell in 2001.
Normals 1991–2020 and records since 1945 from the Seattle Tacoma Area threaded record (Seattle Tacoma Airport, 5 miles southwest). NOAA, through RCC-ACIS.
