BYU students and Provo residents have ridden a weather roller coaster over the past month, experiencing temperature highs in the upper 70s, lows below freezing, coupled with snow and rain.
While students can’t change the weather, understanding the sporadic nature of Provo’s weather patterns can be made easier by learning a few scientific principles.
Clark Christensen, a professor in the Department of Physics and Astronomy, teaches several meteorology classes and spoke to Provo’s sporadic weather conditions.
“What’s really rare for the weather is for the temperature to be the average,” Christensen said. “Ten degrees above or 10 degrees below is not at all abnormal.”
He explained one key to the weather is how the weather changes in relation to a polar jet stream. Polar jet streams are fast-moving air current found at high altitudes that moves east to west, while meandering north and south.
Polar jet streams have a large impact on the weather. According to Christensen, it tends to be relatively cold north of the polar jet stream and relatively warm south of the polar jet stream.
What makes this fall especially interesting, Christensen said, is the entire polar jet stream has been moving quickly relative to Provo, leading to rapid fluctuations between colder-than-average weather and warmer-than-average weather, which helps to explain why Provo has seen both freezing and warm weather in the same week.
While jet streams cover the entire earth, the Utah Valley area is particularly susceptible to weather changes due to various geographic features.
“People from east of the Rockies will notice we have much bigger temperature swings from day to night,” Christensen said. “That’s because of our dry air and also fairly high altitude. … We’ll have a warm day and absolutely freezing night, differing 30-35 degrees.”
Another reason for the weather’s volatility is that Provo is a long distance from the ocean, which helps moderate the weather in areas like western Washington and California.
The mountains tend to have an interesting effect on the weather as well. For example, living on the west side of the mountains leads to more precipitation, Christensen said.
Students on campus have noticed the unpredictable weather over the past few weeks.
“It’s really sporadic,” said Jason Dean, a senior studying Spanish. “We’ll see so many changes within the first few hours of the morning.”
Dean works on campus supervising an early morning custodial crew.
“When I come in at 4 a.m. it’s raining, and by 4:30 a.m. it’s not,” Dean said. “And some of the time it has been warmer at 4 a.m. than when I leave in the afternoon.”
One of the most difficult consequences of the dynamic weather, according to Chelsea Lind, a senior majoring in public health, is it makes it difficult to prepare for the day, because it will be freezing in the morning and sweltering by the afternoon.
“This past week the weather has been great though,” Lind said. “It’s has been cool enough to exercise, but the sun has been out and feels great.”