Record Low & High Set In Same Day
Alamosa, Colorado conquered an impressive feat on Friday; to reach a record low temperature and a record high temperature in the same day!
How about this?
Alamosa, Colorado tied the daily record low this morning, then broke the daily record high this afternoon! All in a day's work, I guess…#COwx pic.twitter.com/IZ8MhDTHc0
— WeatherNation (@WeatherNation) July 11, 2020
The Alamosa weather station (code KALS) dropped to 37 degrees on Friday morning, close to the temperature at which frost starts to form. Then Friday afternoon, the temperature soared +55 degrees to hit 92 degrees! Based on the climate data, 37F tied the record low and 92F broke the record high!
These record temperatures were daily, just for July the 10th, and not all-time extremes. However, the record books date back quite a length of time, beginning in 1906 for Alamosa, CO.
So how is this possible?
Answer: Dry air.
Dry air can heat and cool far easier than moist air. Locations in the western United States notoriously have much drier and lower relative humidity levels. On Friday, there was a massive area of high pressure over the Southwest U.S. Alamosa sits in the San Luis Valley of Colorado. Nearby are large mountain peaks. At night, cool air drains down from the mountains and settles in the valley. Alamosa is in a prime spot to get chilly at night. Then during the day, the San Luis Valley warmed quickly because of the extensive high pressure. That high pressure caused sinking air, which combined with the dry conditions, warmed the lowest elevations as it sank to the surface.
It’s not common to reach a record low and a record high in the same day, but this goes to show how much the temperature can swing under clear conditions with dry weather.