Measurable snow hasn’t fallen in Denver since April 21, a 215-day stretch, which is also nearing a record.
Wednesday features the only chance of snow in the next week and is a long shot. Most days this week are forecast to be quite mild. Highs some 10 to 15 degrees above average are expected Monday and Tuesday and again Friday into the weekend.
Fires may be more probable than snowflakes.
Fire weather watches are up for the mountains west of Denver and most of southern and eastern Colorado, where relative humidity values could drop as low as 7 percent Tuesday, with winds gusting over 30 mph.
“Conditions will be conducive to the rapid spread of new fires,” wrote the National Weather Service. “Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions.”
The bulletin comes less than a week after the Kruger Rock Fire, which broke out last Tuesday near Estes Park in the Rockies west of Boulder, claimed the life of a firefighting pilot working to combat the blaze.
A snowless fall
Once the clock strikes midnight Tuesday, Denver will have broken the record for the deepest stretch into fall without any measurable snowfall, defined as at least a tenth of an inch.
“And that is since 1882,” said David Barjenbruch, a meteorologist at the National Weather Service in Boulder, on a phone call. “The previous record was Nov. 21, 1934, so officially today we’re still tied, but we’re going to break that thing at midnight.”
Barjenbruch explained that Denver’s official observation site has jumped around over the years and included downtown and Stapleton Airport, but is now at Denver International Airport about 10 miles northeast of Aurora.
“Regardless, we’ve had no measurable snow in pretty much of all Denver,” Barjenbruch said. “We’ve had a few tenths of an inch of snow as we had up toward Boulder and Fort Collins. Denver has been in a really dry pocket. It’s been that way pretty much since June; we’ve had very little precipitation.”
Between June and mid-November, Denver averages 7.5 inches of precipitation (from rain and melted snow). This year since June 1, only 1.88 inches have fallen. That’s the lowest amount on record since at least 1994.
Denver could also flirt with another record — their all-time longest stretch without any measurable snowfall.
“The record for that is 235 days in 1887, from apparently early in March to October 25,” Barjenbruch said. “Those are some older records, but those are the official records. As of yesterday [Sunday], we were counting 215 days.”
That means Denver would have to go another three weeks before breaking the record, but if there was a season to do it, this would probably be it.
“We’ve just been in a progressive weather pattern,” said Barjenbruch, referring to upper-air weather patterns that support quickly-moving systems and westerly flow. Those westerly winds pour over the mountains and accelerate into the lower terrain, where the air warms up and dries out.
“It’s been continually dry for many months now,” Barjenbruch continued. “Western Colorado eased their drought during the fall season, but Denver and the Front Range did not get in on those episodes of precipitation.” Only the mountains, he says, proved lucky.
With a La Niña winter, moreover, he thinks that trend will continue — wetter in the mountains, and drier in and around the Denver metro. He said that current snowpacks in the higher alpine regions of the Centennial State are running about 60 to 70 percent on average, with some places only around 30 to 40 percent normal.
“We’re seeing some trends here of a late winter start [in recent years],” explained Barjenbruch. “This isn’t atypical for a La Niña winter to be dry along the Front Range, and it’s quite common as we get into the second or third years of La Niña.”
The dry pattern looks to continue into the future, but there has been some improvement — according to the U.S. Drought Monitor, no place in the state is in Level 4 out of 4 “exceptional drought,” compared to more than a quarter of Colorado at this time last year.
“We had a really wet spring that started with that March blizzard and continued quite wet with frequent snows through March into April with some gently soaking rains through May and a relatively wet June,” Barjenbruch said. “Without that, we’d have had a really rough fire season.”