The story
From Colorado + low. From being a low pressure system originating in the uploads of Colorado.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A fast moving high precipitation winter storm system originating out of Colorado, and traveling east across the United States, dumping much snow on the Great Plains and the Midwest. Full definition →
From Colorado + low. From being a low pressure system originating in the uploads of Colorado.
Etymology from Wiktionary, CC BY-SA 4.0.