On Thursday night and Friday, flakes may finally fly in Denver, ending a record-setting snowless streak. The predicted snowfall is part of a significant storm system that will sweep from the Rockies to the Great Lakes between Thursday and Saturday.
Not a stitch of measurable snowfall, defined as more than a tenth of an inch, has come down yet this season in the Mile-High City, beating out the previous record for the latest first snowfall in a calendar year by 17 days. The previous latest first snow occurred on November 21, 1934.
This snowless streak extends back to last spring. Not since April 21, when 2.6 inches fell, has Denver seen measurable snow — a period of 230 days. That streak is nearing the record for the longest snow-free period at any time of year — 235 days — which spanned from March through October in 1887.
Salt Lake City is also expected to see their first snow of the fall Thursday and Friday.
Both Denver and Salt Lake City have seen limited precipitation and above normal temperatures since September amid a warm and dry pattern in the western U.S. Wildfires have even flared up in Colorado and Montana this month, which is practically unheard of.
But a cooler and more unsettled weather pattern is about to commence in the western states, while it turns abnormally warm in the eastern two-thirds of the nation.
Ending the snowless streak
Winter weather is likely in the Rockies by Thursday night and it’s expected that the snowless streak in Denver could come to an end just shy of nabbing an official record. Snowfall will be light in nature east of the Rockies though, with accumulations in Denver proper expected to range from a dusting to an inch. Any snow bands that do set up should wind down by lunchtime Friday.
“Not as bullish for snow chances and amounts on the plains as previous, although we’re still forecasting accumulating snow for the I-25 corridor including that all important snowboard out at [Denver International Airport],” wrote the National Weather Service in Boulder in an online technical forecast discussion.
Officially the Weather Service is forecasting an inch at the airport.
“For getting an accumulating snow in Denver, we’re pretty confident we’ll get a few tenths,” said Zach Hiris, a meteorologist at the Weather Service in Denver. “The forecast is pretty good at the airport.”
Salt Lake City has been behind on snowfall too; currently they’re seeing their fourth longest streak without snow. They’re at 257 days snow-free right now. Several inches are predicted in the city on Thursday and Friday so it’s unlikely they’ll make it to the 285 day record that ended with a Christmas Eve snowfall in 1939. That’s the year The Wizard of Oz came out.
Even Goodland, Kansas is on the leader board for both latest first snowfall and longest snowless streak. The community stands at 232 days without snow, a far cry from the record 288 days that stretched from April 1949 to January 1950. That January 24, 1950 date also marked their latest first snowfall on record.
As this next storm system approaches, winter storm watches are in effect for the higher elevations of the Rockies, where one to two feet of snow could fall, as well as along a strip through northern Nebraska, southern South Dakota, parts of northern Iowa and the Corn Belt and western Wisconsin.
Half a foot or more is possible as the storm system rolls over the Plains late Thursday into early Friday, though confidence in exactly where the sharp-edged system will track isn’t yet high enough to pull the trigger for a winter storm warning. The same system could drop double-digit snow totals in the Upper Peninsula of Michigan.
This storm system will drag a cold front through the eastern half of the nation, potentially setting off severe thunderstorms from Louisiana through the Tennessee Valley Friday.
Paltry precipitation in the eastern Rockies and Plains
It hasn’t just been snow that’s eluded Denver; precipitation in general has been hard to come by. Part of the issue the Metro, and the Plains as a whole, have been facing over the past several months has been downsloping. That occurs when air moves down the mountains, in this case the Rockies.
Twenty-two out of 30 days during the month of November featured a westerly component to the winds, which drags air down the mountains. When that occurs, air pockets become compressed, warming and drying.
West and southwesterly winds bring the driest air into Denver, which has been one ingredient that’s eroded precipitation chances this season. According to the U.S. Drought Monitor, 14.34 percent of Colorado is under a level 3 out of 4 severe drought, the lack of water taking a toll.
Since the start of September, Denver has only seen 0.43 inches of precipitation; their average during that time frame is 3.06 inches, placing the city 86 percent behind average for that window.
Still, even the scant precipitation reflects a marked year-over-year improvement from inveterate drought gripping the region. Last December, severe drought was three times as expansive in Colorado, and a quarter of the state was in top-tier “exceptional drought.”
Jason Samenow contributed to this article.