Winter storm warnings, advisories issued; Cold front breaking Utah's record heat

SALT LAKE CITY — Utah's record warm and late summer-like temperatures are coming to an end as an approaching storm is expected to bring below-average temperatures and snow in the mountains.

The National Weather Service issued its first winter storm warning of the season Wednesday ahead of a storm that could potentially dump over a foot of snow in several Utah mountain ranges. The agency also issued a winter weather advisory for other areas.

Plenty of rain is also expected in the valley communities on Thursday and Friday.

“It’s going to feel a lot more fally here,” KSL meteorologist Matt Johnson said.

Timing and accumulation of storms

The first major storm of the season hits Utah from the Pacific Northwest. A few small showers are also possible on Wednesday, but the much larger rain is expected to arrive on Thursday.

Updated models now indicate showers will occur across northern Utah and the Wasatch Front beginning early this morning and possibly during the morning commute, Johnson said.

“It will be a double whammy, with the first whammy being a little weaker,” he said. “Above 9,000 feet there will be light valley rain and mountain snow.”

Showers will continue to occur across the state throughout the day before a stronger cold front is expected to arrive as early as Thursday night. The second front will cause temperatures to drop further and at the same time bring heavier rainfall. Snow levels can drop to as low as 5,000 feet.

Storms will continue into Friday morning before beginning to clear across most of the state throughout the day. Mountain roads and passes will likely be slick and motorists should drive with caution, the weather service's warnings and observations say.

Johnson said some models suggest valley communities could receive snowflakes, but he doesn't think there will be much accumulation in this case.

KSL weather models are now less optimistic about the storm's precipitation potential, especially because the storm will now move through the state faster than originally expected. Still, Johnson said many communities along the Wasatch Front could receive over a half-inch of rain by Friday evening.

Models also suggest that the core of the system could affect parts of eastern, central and southern Utah, so those areas could receive higher totals.

The highest rainfall amounts are still forecast in the mountains, which is important as soil moisture – a key factor in the efficiency of spring snowmelt – begins to dry out again. The Natural Resources Conservation Service reported that soil saturation in the Uinta Basin, Western Utah and St. George regions had fallen to the low 10th percentile by the end of September.

“Flipping the switch is really good news,” Johnson said.

cooling

The forecast is in stark contrast to recent weeks in Utah. Salt Lake City is expected to top 80 degrees again on Wednesday, bringing the number of 80-degree days this month to 15 – five more than the previous record set in 1996.

Utah's capital also experienced its first recorded 90-degree October day on October 4th. Given the record warmth, it's no surprise that the average temperature in Salt Lake City this month is expected to be 70.6 degrees – over 10 degrees above the record set in 2015.

The approaching storm will at least help bring these numbers closer to normal. Freezing conditions are forecast for most locations outside the Wasatch Front and lower Washington County, according to the National Weather Service.

High temperatures along the Wasatch Front and northern Utah are expected to drop from the upper 70s and low 80s on Wednesday to the low to mid 60s on Thursday; They may only peak in the low 50s on Friday and stay in the 50s and 60s over the weekend. Nighttime low temperatures during this time are forecast to drop into the 30s and 40s, possibly even into the 20s in northern Utah communities.

High temperatures in St. George – which has also been unseasonably warm this month – are expected to drop from the low 80s on Thursday to the upper 50s on Friday before rising back into the 60s over the weekend. Overnight lows will fall into the 40s during this time.

Is there more to come?

The approaching storm could be the first of several storms in the next few weeks. Several long-term models indicate that most of Utah has a higher chance of above-average precipitation by the end of the month as fall conditions return to the state.

It suggests there could be more intermittent storms in the next few weeks, Johnson explains.

“This is good news because we really need to replenish soil moisture now before we put down the heavier snowpack,” he said. “This is a promising sign.”

Complete seven-day forecasts for areas across Utah can be found online at the KSL Weather Center.