Dennis’ Tidbits


January 14, 2020

Crazy Chicago and the weather according to “C”

Dennis 5Are you ready for this one? Here on Sunday, Lake Michigan had way better waves than Lake Laguna where it was barely knee high for two-year-olds and Chicago’s beaches were resembling Thalia Street on a good day with clean three to five-foot peaks at seven second intervals. Hey, I can’t make this stuff up! 

Let’s break it down…on Saturday a strong low pressure was strained near Toronto, Canada, a few hundred miles to the northeast of Chicago, while a strong high pressure was anchored just a few hundred miles to the north of the low. That strong pressure gradient between the high and the low sent northeast winds over Lake Michigan all day, causing solid wind waves as high as 10-12 ft. by Saturday afternoon. 

The winds began to abate by that afternoon and completely slackened throughout the overnight hours. As Sunday dawned, the surface of the lake had considerably cleaned up, as consistent three to five-foot clean peelers greeted some hardcore surfers who were totally ready for these most rare conditions. The air temp was 24 with a water temp a brisk 41. No problem! They had quarter-inch wetsuits with booties and gloves, taking full advantage of these most rare conditions, and knowing well that it would only last a few precious moments before the surf went flat, but they scored big time. The planets almost have to line up for this most rare event to happen. “Hey, where’d you surf yesterday?” “Um, Chicago.”

Here’s some more weather terminology…. 

Cirriform: All species and varieties of cirrus, cirrocumulus, and cirrostratus clouds composed of small ice crystals, usually transparent and white; often producing 22.5-degree halo phenomena not observed with other cloud forms. Average height upward from 20,000 ft. in middle latitudes.

Cirrocumulus: A cirriform cloud appearing as a thin sheet of small white puffs resembling flakes or patches of cotton without shadows; sometimes confused with tiny altocumulus. These clouds make for great sunsets around here.

Cirrostratus: A cirriform cloud appearing as a whitish veil, usually fibrous, sometimes smooth; often produces halo phenomena and sun dogs; may totally cover the sky. The sun is still slightly visible most of the time but appears fuzzy and can be viewed straight on without damage to the viewer’s retina.

Cirrus: A cirroform cloud in the form of thin, white featherlike clouds in patches or narrow bands; has fibrous and/or silky sheen; large ice crystals often trail downward a considerable vertical distance in fibrous, slanted, or irregularly curved wisps called mare’s tails.

Clineometer: An instrument used in weather observing for measuring angles of inclination. It is used in conjunction with a ceiling light to determine cloud height at night. I have one of these in my arsenal as well.

Convection: I mention this term often when I write about thunderstorms and turbulent weather. In general, mass motions within a fluid resulting in transport and mixing of the properties of that fluid. In meteorology, atmospheric motions that are predominantly vertical, resulting in vertical transport and mixing of atmospheric properties. These procedures often develop thunderstorm clouds  (cumulonimbus clouds).

More terms next time, ALOHA!