An atmospheric river swept into Colorado on Monday night, which is forecast to blanket Southwest Colorado mountain passes with snow in advance of the Thanksgiving holiday.
“The fire hose is getting turned on,” said Dennis Phillips, a meteorologist with the National Weather Service in Grand Junction.
The storm system is expected to move out by Thursday morning.
A hazardous weather outlook warning is in effect for most of Colorado and a winter storm warning is in effect in the San Juan Mountains, including the communities of Telluride, Ouray, Silverton and Hesperus.
The NWS is predicting up to 36 inches of snow on Red Mountain, Coal Bank and Molas passes; up to 40 inches is possible locally on Wolf Creek Pass. With warmer, moisture-heavy storms, forecasters were less certain exactly at what elevation rain will turn to snow throughout various locations of the state, Phillips said.
“It takes a degree or a half a degree to switch stuff over to snow,” Phillips said. “Right now it looks like … above maybe nine, and for sure above 10,000 feet, they're just going to get hammered.”
Little snow is expected to accumulate in Durango.
The Colorado Avalanche Information Center is predicting the avalanche danger will spike later in the week in the southern mountains thanks to the rapid accumulation of new snow in some places atop a weak, unsupportable layer. An avalanche watch is in place through Wednesday evening.
“This storm's fast and furious nature means that new snowfall will quickly develop into a cohesive slab on top of the variety of weak snow surfaces that developed on shady and sheltered slopes during the last two weeks of dry weather,” the forecast discussion issued Tuesday morning read. “By the end of the day Tuesday, you are likely to trigger avalanches on many slope.”
For anyone traveling Thanksgiving Day, Phillips said the storm is expect to move out by Thursday morning, but the status of highways should be monitored at cotrip.org.
rschafir@durangoherald.com
