The two boats became stranded after the first boat, filled with nine people, got stuck when some rope became tangled in its propeller. Five people in a second boat decided to help by towing the other boat with the same rope, but it tangled in that boat's prop, too.
Cannon said the boaters got the rope untangled during the storm, but then the boats began to take on water. Some got out of the boats and waited out the storm in the waist-deep water. Cannon said all of the boaters were either wearing or had access to life jackets.
The storm was less merciful to one boat, which was almost completely submerged by the time the 6 p.m. storm calmed.
National Weather Service meteorologist Mike Conger said the storm moved over the Wasatch Front late Thursday, delivering rain overnight. By early Friday morning it had settled over the upper part of the state, from the Idaho border to northern Utah County. Though it never became as strong as the storm that doused northern Utah a day earlier, it ultimately dropped .18 inches of water at Salt Lake City International Airport.
The weather service also issued a flood warning for Utah and Washington counties Friday evening, cautioning of heavy, consistent rain falling along Highway 59 from south of Hurricane to Hildale and Apple Valley. In Utah County, forecasters looked for heavy rain through most of Friday evening and said there had already been reports of flooded roadways in some parts of the area.
Most flood deaths occur in cars, forecasters said, and they warned that drivers who come across covered roads should turn around instead of attempting to drive through.
In addition to water, the storms which Conger said should continue through the weekend should help bring temperatures closer to the seasonal norm, which is about 90 degrees for Salt Lake City. Conger explained that the rain itself will have a cooling effect and the cloud cover will further absorb some of the heat.
Conger added that the thunderstorms are normal for this time of year, which is said is sometimes known colloquially as "monsoon season."
In Salt Lake City and the Ogden and Tooele areas Friday, highs were in the high 80s and lower 90s.
Temperatures were about the same in Utah County. Similar conditions will persist along the Wasatch Front through the weekend.
In southern Utah, hot temperatures will remain the rule. Forecasters reported a high of 106 Friday in St. George, along with wind and some thunderstorms. Temperatures will drop several degrees over the weekend but will stay in the triple digits.
The Utah Division of Air Quality predicted moderately breathable air Friday and Saturday in Salt Lake, Davis, Cache, Utah and Weber counties. Box Elder and Duchesne counties should have good air quality as the weekend begins.
Forecasters reported a high in Salt Lake City of 93 degrees Friday and expected a high of 92 degrees Saturday; Ogden hit 88 and expected 89, respectively; Provo 95 and 91; Logan 88 and 86; Wendover 88 and 90; Duchesne 93 and 88; Cedar City 94 and 90; St. George 106 and 104; and Moab 96 and 99.