Meteorological Synopsis
In Salt Lake Valley, the day began with calm but cloudy weather. As the day progressed, the clouds became steadily darker until nearly all light was obscured. Winds were still nearly calm, with the exception of a few microbursts. Hail preceded and followed this tornado, which was rated a strong F2 on the Fujita scale. At 12:41 p.m., 11⁄2 inches (3.8 cm) diameter hail was reported near the town of Herriman. Afterwards, the storm started rotating, and at around 1:00 pm, many people reported seeing the storm rotate (forming a mesocyclone) as it moved into downtown Salt Lake City. A non-descending funnel cloud developed and traveled from western downtown toward the northeast before terminating near Memory Grove Park upon reaching the base of the Wasatch Mountains.
Read more about this topic: 1999 Salt Lake City Tornado