Sierra cement, yellow snow, pineapple express.
Haboob, Texas norther, bomb cyclone.
They seem like ridiculous terms used to describe a messy bedroom or types of ice cream.
But they’re actually weather terms, and meteorologists use them.
Sierra cement refers to the heavy, wet snow that often falls on the West Coast.
Yellow snow is not urine, but snow turned golden by pine or cypress pollen.
And pineapple express is a band in the atmosphere that transports moisture from Hawaii and the tropics to the coasts of the U.S. and Canada.
Who develops these terms and how they enter the public lexicon are often murky.
“Sometimes, someone will put something out there and it just sticks, especially in this day and age with social media,” said Jeff Colton, a meteorologist with the National Weather Service in Grand Junction. “These (terms) just gain traction and keep going.”
Some terms originate with the meteorological community.
“Pineapple express” first arose in the 1970s with satellite images that clearly showed rivers of moisture stretching to California. A meteorologist in Seattle may have coined the term, but debate remains as to which weathercaster said it first, according to San Francisco Bay Area meteorologist Jan Null.
The media is often responsible for both creating and popularizing new weather terms. The North Kitsap Herald in Washington was one of the first publications to use “snowpocalypse” after a storm in 2008. The Washington Post and other national publications spread the term “snowmageddon” during major snowstorms that struck the East Coast in 2010.
Sometimes, it can just be meteorologists looking for a shorter way to say often complex weather phenomenon.
“As scientists, we also like shorthand,” said Ankur Desai, a professor and department chairman of the University of Wisconsin – Madison’s Atmospheric and Oceanic Sciences Department. “Forecasters, in particular, need to have ways to communicate complex ideas in simple words.
“A lot of them have come out colloquially. Some of them go back to the days of weather forecast discussions as they were transmitted by teletype,” said Desai, who is also the assistant chief editor of the American Meteorological Society’s Glossary of Meteorology.
The Glossary of Meteorology is the American Meteorological Society’s attempt to standardize and clarify weather terms for both scientists and the public.
“The glossary is focused first and foremost on being precise for the science so that we can all be on the same page,” Desai said.
The Glossary of Meteorology is a collaborative effort, so members of the meteorological community will reach out to Ward Seguin, chief editor of the glossary, when a new word appears that ought to be added and defined.
Committees within the American Meteorological Society then vet the word, looking at criteria like how often the term is used in academic papers or by journalists and whether the word has an agreed upon definition.
“Sometimes, the committees will reject the term just because it’s not that commonly used or there’s not enough agreement on the meaning of the term, or it’s really a very colloquial term that has importance but maybe not for something like the glossary of the American Meteorological Society,” Desai said.
Some words like snowmageddon never make it into the glossary because they have no meteorological standards, he said.
But others like pineapple express or Texas norther, an arctic cold front that drops temperatures quickly and dramatically, will be included because they describe specific weather phenomenon that meteorologists track.
The Glossary of Meteorology has evolved a lot since its first edition was published in 1959.
So have many of the terms that meteorologists use.
Desai recently found old paper copies of the Glossary of Meteorology and recognized few of the terms meteorologists were using at the time.
“There were all sorts of words in there that I had no idea what they were,” he said. “There were very specific and unique weather phenomenon that nobody calls that way anymore.”
In recent years, scientists have switched from pineapple express to “atmospheric rivers” to more accurately describe the precipitation transported in long, thin streams from the tropics to the Pacific Coast.
“We’re trying to knock down some of those slang terms and go more with the scientific terminology,” Colton said.
While haboob and bomb cyclone might seem like slang, they’re not.
A haboob is a large sandstorm that can create a “wall of dust” thousands of feet high. The word is derived from the Arabic word habb that means “to blow,” according to the Glossary of Meteorology.
A bomb cyclone refers to a spinning storm that loses pressure rapidly, often producing heavy precipitation and fast winds.
Desai said meteorologists aren’t moving entirely away from popular terms, but “there's definitely been a demand to make terms clearer.”
Like their genesis, it’s hard to trace the disappearance of weather terms.
Years from now meteorologists may look back and wonder what forecasters meant by Sierra cement or pineapple express.
“It’s a natural evolution,” Desai said.