Frost/Freeze in Grand Flat and Arches, Utah

Minimum temperatures across the zone ranged from 32F to 23F. The minimum temperature of the event was 23F, recorded at the UTHAD site Harley Dome, at MP 226 on I-70. In addition, the KCNY ASOS at Canyonlands Airport recorded a minimum temperature of 25F. 8 of the available 16 sites recorded temperatures at or below 32F for at least 3 hours, with these temperatures lasting for on average 5.5 hours. Only 4 of the available 16 sites recorded temperatures at or below 28 degrees for at least 3 hours, with these sites seeing an average duration of 3.5 hours. Based on these data, this event in Utah Zone 027 qualifies only as a Freeze.

An unusually cold air mass had moved in over eastern Utah and western Colorado by the night of April 6th to the 7th. This already cold air was compounded by clear and calm conditions that promoted radiational cooling across much of the region. At this point in the year, only the lowest elevations of eastern Utah and western Colorado had acquired enough Growing Degree Days to warrant freeze highlights, as important agricultural assets, with particular emphasis on fruit trees, were beginning to bloom and a hard freeze event could be disastrous. Luckily, many of these crops were not damaged by this freeze event, even though many locations did hit hard freeze criteria.