Much More Rain, Snow on Way Until Friday Morning, 10 a.m.

Staff Writer

The last and likely largest of the series of storms that began last Thursday is underway now, Thursday, Dec. 15, at about 1 p.m., with about 1.42 inches of precipitation already in the bag for the 9,000 foot level (about eight inches of snow) on Mammoth Mountain and about half that for the town of Mammoth located roughly at the 8,000 foot elevation.

The rain started this morning, brought in by a strong “atmospheric river” event and there is more on the way before the storm exits tomorrow morning - a lot more.
In fact, a whole lot more.

“We are going to see another two more inches of rain between 4 p.m. and 10 p.m. for the Town of Mammoth and another 1.5 inches from 10 p.m. to 4 a.m. tomorrow morning, Dec. 16.

“That will bring us another 3.5 inches of precipitation,” he said.

That will translate to as much as one to three feet of snow in Mammoth, once the temperatures drop this evening, he said, with more than that on Mammoth Mountain and even more on the highest elevations of the Sierra crest, he said.

“It’s going to be a mess out there after 10 p.m.,” he said. “If you don’t have to travel, do not travel. Why would you?"

Temperatures will plummet to singel digits on the tail end of the storm tomorrow and stay there, making it a cold, cold weekend, including the big Night of Lights event on saturday at Canyon Lodge.

Dress warm, travel with chains and, slow down.

Here's a few more details:

The National Weather Service issued its strongest alert this afternoon; a Winter Storm Warning:
The storm is forecast to begin as rain today and into the night, then turn to snow toward the morning hours.

According the National Weather Service, a major atmospheric river (AR) storm will push into the region Wednesday night, through Friday, bringing high winds, heavy rainfall, and heavy high elevation snow. The main changes to the forecast (since yesterday and earlier this week) have been to increase expected precipitation (QPF) across the Sierra and western Nevada foothills, as well as increasing snow amounts for highest elevations above 8,000 feet.

"Heavy precipitation will move into the Northern Sierra tomorrow morning and then spread south into the Lake Tahoe area and Mono County by Thursday afternoon," according to the NWS. "Snow levels will begin fairly high at around 8,000 feet. Heavy rainfall will peak out after 4 p.m. Thursday and go to around midnight in the Lake Tahoe area, and continue after midnight for Mono County.

"Much colder air will push into the region Thursday night, bringing snow levels down to valley floors by Friday morning right as the precipitation begins to wind down. This will really limit the amount of snow coming down to the lower elevations, but for the highest elevations above 8,000 feet, multiple feet of heavy wet snow are likely.
On Friday, the last push of moisture will change over to snow for pretty much all locations as the cold air moves in, according to the NWS. The temperatures are expected to remain very cold into Christmas week.

No major storms are forecast for the week, but some smaller storms are possible.

The bottom line, travelers should be careful Thursday and Friday, especially if they are traveling to or from the north, where elevations are higher overall, although the Sherwin Grade area on U.S. Highway 395 could be impacted by snow and rain, depending on the elevation.