Cirrus clouds are atmospheric clouds characterized by thin, wispy strands, often bunched into tufts. They range in color from white to faint gray and form when water vapor undergoes deposition at altitudes above 5,000 m (16,500 ft) in temperate regions and above 6,000 m (20,000 ft) in tropical regions. They also form from the outflow of tropical cyclones or the anvils of cumulonimbus clouds. Since these cirrus clouds arrive in advance of the frontal system or tropical cyclone, they indicate that the weather conditions may soon deteriorate. While they can indicate the arrival of precipitation, cirrus clouds themselves produce only fall streaks (falling ice crystals that evaporate before landing on the ground). Jet streams can stretch cirrus clouds across continents, but the clouds will remain only a few kilometers deep. When visible light interacts with the ice crystals in cirrus clouds, it can produce glories, sun dogs, and fire rainbows.

Read more: https://en.wikipedia.org/wiki/Cirrus_cloud

_______________________________ Today's selected anniversaries:

1911:

Mexican president Porfirio Díaz and the revolutionary Francisco I. Madero signed the Treaty of Ciudad Juárez to end hostilities between each other's forces, concluding the initial phase of the Mexican Revolution. https://en.wikipedia.org/wiki/Treaty_of_Ciudad_Ju%C3%A1rez

1927:

Aboard the Spirit of St. Louis, American aviator Charles Lindbergh completed the first solo non-stop transatlantic flight, flying from Roosevelt Field near New York City to Paris–Le Bourget Airport. https://en.wikipedia.org/wiki/Charles_Lindbergh

1946:

While working with a mass of plutonium known as the demon core, Manhattan Project physicist Louis Slotin accidentally exposed himself to a lethal dose of hard radiation. https://en.wikipedia.org/wiki/Louis_Slotin

2014:

A Taiwanese man carried out a stabbing spree on a Taipei Metro train, killing four people and injuring 24 others. https://en.wikipedia.org/wiki/2014_Taipei_Metro_attack

_____________________________ Wiktionary's word of the day:

orature: The oral equivalent of literature: a collection of traditional folk songs, stories, etc., that is communicated orally rather than in writing. […] https://en.wiktionary.org/wiki/orature

___________________________ Wikiquote quote of the day:

In his own way each man must struggle, lest the moral law become a far-off abstraction utterly separated from his active life.   --Jane Addams https://en.wikiquote.org/wiki/Jane_Addams