The zone from Texas north through the Dakotas and Minnesota is expected be hit hardest by the powerhouse storm. It is likely to meet the criteria of a “bomb cyclone,” its pressure dropping 24 millibars in 24 hours between Tuesday and Wednesday afternoon. The lower the pressure and the faster it falls, the more intense the storm.<doc-sep>“Bomb cyclone” went from goofy meteorological term to serious business Wednesday as a turbocharged blizzard walloped Colorado’s mountains, Front Range and Eastern Plains with hurricane-force wind gusts, heavy snow and general misery. Gov. Jared Polis declared an emergency after the storm stranded motorists and forced massive highway and road closures across the state. The blizzard also halted air travel at Denver International Airport, cut power to more than 200,000 homes and businesses, disrupted public transportation services and sent trees falling across the metro area. Life should begin returning to normal Thursday morning, though the storm’s effects will persist as Xcel Energy works to restore power to thousands. And several large metro school districts — including Denver, Cherry Creek, Jeffco, Douglas County, Littleton and Westminster — called off classes and activities for another day. Polis’ statewide declaration resulted in the activation of the Colorado National Guard, making its units available to rescue stranded motorists and for search, rescue and life-safety operations. Hours earlier, the storm had turned deadly after a Colorado State Patrol trooper who was responding to a slide-off on Interstate 76 in rural Weld County was struck by another driver who apparently had lost control of his vehicle. In Denver, where police reported 125 crashes on city streets throughout the day, a separate emergency declaration by Mayor Michael Hancock will last for up to seven days. RELATED: Colorado weather: Bomb cyclone lived up to the hype, keeping even the most hardy people indoors “We are seeing improving conditions, (and) the brunt of the storm is moving east of Interstate 25 and east of Denver,” National Weather Service meteorologist Jim Kalina said about 5:30 p.m., but he warned: “Winds will still be strong.” Northeastern Colorado still faced a blizzard warning through noon Thursday, and the weather service warned against travel on the roads Wednesday night. East of Denver, Interstate 70 was to remain closed to the Kansas border overnight, while, south of the city, state officials planned to keep Interstate 25 closed overnight between Lone Tree and Colorado Springs. In the mountains, the heavy snow brought the return of avalanche warnings across a swath of central mountains from north to south that had experienced record snow slides in the previous week. Snowfall totals vary widely Along the Front Range, the storm largely delivered on meteorologists’ dire forecasts of wind gusts of up to 80 mph or more, though snowfall totals varied starkly. The weather service office in Boulder cited snow reports ranging from 20 inches in Nederland, and nearly as much in several foothills communities, to just 6 inches in Denver by 4 p.m., as the storm drifted out of the metro area. Some places got even less. The day began innocently enough in the city, with driving rain and light wind gusts. “I’m waiting for the hype,” said Rob Roberts, 38, from his front porch in northwest Denver as he considered driving to work at Buckley Air Force Base in Aurora, skeptical of taking a snow day. “It’s a big to-do for what looks like slushy rain so far.” A short time later, big flakes began falling — and then flying, as the wind whipped. It was just the beginning. Colorado experienced a bombogenesis event — colloquially called a bomb cyclone — of the sort that’s more common on the East Coast. If the barometric pressure drops rapidly enough in a 24-hour period, it turns a winter storm into a cyclone with intense winds, according to Weather Nation meteorologist Chris Bianchi, who was among those sounding the alarm ahead of Wednesday’s storm. “It’s obviously a very rare circumstance for this to happen in Colorado,” said Bianchi, also a Denver Post contributor. The early conditions were equivalent to a Category 1 hurricane, the National Weather Service said. In some places — especially to the northeast and east of Denver and near the Palmer Divide — it quickly got even worse as snow fell at the rate of nearly 2 inches per hour in some places. Sweeping tractor-trailers sideways But the wind was the main event, as fast-forming ice and whiteout conditions rendered roadways hazardous. Before noon, the trouble became apparent as drivers ignored warnings and attempted to navigate a slushy and ice-covered I-70 east of Aurora. High winds made the highway invisible at times and, near the highway’s closure point at Airpark Road, swept at least a dozen tractor-trailers sideways, blocking the interstate. The winds were so strong that they snapped the metal posts of a sign marking the exit. Nearby, speed limit signs were bent in half, while traffic lights — some no longer functional — bobbed in the wind on their thick metal beams. At Denver International Airport, moderate snowfall blown by wind gusts reaching 80 mph or more forced the closure of all six runways by the afternoon — for only the fourth time in DIA’s 24-year history — and littered Peña Boulevard with wrecks that brought traffic to a standstill, stranding some motorists for hours. While the concourses and terminal stayed open, they effectively served as massive warming huts. Earlier wind reports to the weather service included hurricane-strength gusts of 92 mph in Glen Haven in Larimer County and 77 mph in Bennet, but the wind was fierce across the Front Range and Eastern Plains. Major closures affected interstates 70 and 76 on the Eastern Plains, I-70 in the mountains, I-25 south of Denver and north of Fort Collins, and many mountain passes. In Weld County, both the Colorado Department of Transportation and county plows gave up on clearing roads by mid-afternoon, due to low visibility, according to Fort Lupton Fire. To the south of the metro area, several shelters filled in Douglas County in the afternoon as authorities rescued stranded motorists. Vehicles got stuck in snow drifts between Larkspur and Monument, prompting rescues by Colorado State Patrol. And about 100 vehicles were stranded mid-afternoon on Highway 86 between Kiowa and Elizabeth, authorities said, as local firefighters used four-wheel-drive vehicles to reach them one by one. The storm also affected the Colorado Springs area, where authorities said city police and El Paso County sheriff’s deputies were attempting to reach about 1,000 stranded drivers. More than 20 emergency operations centers opened Wednesday along the Front Range. More than two dozen shelters were opened up, too. As they aided in the rescues, state troopers were mourning the death of one of their own, Cpl. Daniel Groves, 52. While he was at the scene of the slide-off on I-76 just west of Roggen, he was hit by a 2001 Volvo driven by John Carpenter, 58, of Centennial, according to the state patrol. Groves was taken to Platte Valley Medical Center, where he was pronounced dead. Carpenter also was injured and taken to the medical center with moderate injuries. The state patrol said it was investigating high speed in poor driving conditions as a possible cause of the fatal crash. Downed trees and power lines In Aurora, Denver and other cities, wind and fallen trees brought down power and utility lines. Xcel Energy said 500 employees and contractors were working feverishly to respond. Still, utility officials expected a “multi-day recovery effort,” and at 10 p.m., Xcel reported 121,270 customers still without power in its large coverage area, due to 2,214 separate outages; the utility said it restored service to about 287,000 customers throughout the day. “We were managing things okay,” Xcel spokesman Mark Stutz said, “but then we ran into this almost historic jump up (in outages) in such a short period of time.” Spotty power also affected at least five hospitals in the metro area and Pueblo that said they were operating at some point Wednesday on backup generators. The storm brought many other disruptions, including to the Regional Transportation District, which suspended its free downtown MallRide for several hours as regular bus routes and rail lines experienced significant delays. The University of Colorado A Line to the airport also experienced significant service lags, and at one point, A Line trains were stalled near the airport because of a frozen switch.<doc-sep>A powerful storm will unleash a ferocious mix of snow, rain and wind across the central USA through Thursday. "While not a tropical system, winds will rival what's seen in a Category 1 hurricane," said weathermodels.com meteorologist Ryan Maue. The worst weather is forecast for the Plains, from Texas up to the Dakotas. "We expect a major blizzard to unfold with winds likely to approach hurricane force, heavy snow and massive drifts," according to AccuWeather meteorologist Alex Sosnowski. Wednesday, 1-2 feet of snow and howling winds will lash portions of Colorado, Wyoming, South Dakota and Nebraska, where blizzard warnings are in effect. The National Weather Service warned of "impossible travel conditions." "You risk becoming stranded if you attempt to travel through these conditions," it said. A blizzard warning was issued for Denver, where 4-7 inches of snow and wind gusts of up to 44 mph are forecast for Wednesday. At Denver International Airport, delays and cancellations will be likely, AccuWeather said. Wild, destructive winds, gusting more than 100 mph, are forecast in Texas, New Mexico, Kansas and Colorado, where widespread power outages are possible. Blowing dust will reduce visibility to less than a mile at times. The weather service office in Midland/Odessa, Texas, said Wednesday could be "the windiest day in years." More:Tornadoes cause damage in south; no injuries reported "High winds may end up stretching over 1 million square miles of the central states with this storm," AccuWeather's Sosnowski said. In the Upper Midwest and around the Great Lakes, as much as 3 inches of drenching rain on top of mounds of already-fallen snow and sodden soil could lead to flooding. "The greatest risk of flooding will tend to be in urban and poor drainage areas where piles of snow are blocking storm drains," according to AccuWeather meteorologist Kristina Pydynowski. After a chance of severe thunderstorms Tuesday in Texas, the tornado threat in the South in this storm is lower than in the past two big storms. The storm is unusually potent and "will have an 'eye-like' feature similar to a hurricane," according to Maue. More:Check your weather forecast The Weather Channel named the winter storm Ulmer. No other private weather firm, nor the National Weather Service, uses that name. While the central USA endures the storm, both coasts will see mostly tranquil weather this week.<doc-sep>
Thousands of Coloradans woke up in the dark Thursday after a winter storm system pounding the central U.S. knocked down power lines, grounded flights and buried highways in snow. As many as 74 million people were expected to face some type of severe weather ranging from blizzard conditions to heavy rain and flooding through Friday. Colorado Gov. Jared Polis declared a state of emergency Wednesday and tweeted that the National Guard had been activated to assist in search and rescue and other operations. Authorities said 1,100 motorists were "stuck and stranded" in "treacherous conditions" on roads in Colorado's El Paso County. Sheriff Bill Elder added that search and rescue operations would continue through the night. His advice was to "STAY HOME." Around 86,000 customers in Colorado were without electricity early Thursday, according to Xcel Energy. Another 47,000 had no power in New Mexico and northern Texas. The storm underwent bombogenesis — also known as a bomb cyclone — according to The Denver Post, a term used when a storm drops 24 millibars, or units of atmospheric pressure, in 24 hours or less, according to Weather.com. We still have to get through a severe weather threat today but appears what is going to make the #2019PlainsBlizzard "Historic" was its enormous high wind field https://t.co/RLtR9s5yYP — Bill Karins (@BillKarins) March 14, 2019 It has contributed to at least one death. A Colorado State Patrol officer, Cpl. Daniel Groves, 52, was killed Wednesday after he was struck by a vehicle on Interstate 76 while responding to another vehicle that slid off the road. The patrol said in a statement that "high speed in poor driving conditions is being investigated as a possible causal factor," but the incident was under investigation and no charges have been filed. Denver International Airport's runways were shut down Wednesday, and almost 1,400 flights were canceled amid the whiteout, the Denver Post reported. The newspaper noted that it was only the fourth time in the airport's history that runways had been closed. More than 5 inches of snow was recorded at the airport as of 5 p.m. Wednesday, while parts of Colorado Springs and Aurora reported 10 inches, according to the weather service. Current conditions at DEN 👇🥶 pic.twitter.com/YFR4q87tky — Denver Int'l Airport (@DENAirport) March 13, 2019 Denver remained under a blizzard warning through midnight with as much as a foot of snow in the forecast. The state Department of Transportation closed stretches of interstates 25 and 70 until at least Thursday morning due to blizzard conditions, and other highways were also closed, NBC affiliate KUSA of Denver reported. Blizzard warnings stretched on a large swath of the central U.S., from eastern Colorado and Wyoming, portions of Nebraska and large parts of the Dakotas and into western Minnesota as of Wednesday night, while eastern Nebraska, southeastern South Dakota and parts of Iowa were under flood warnings. Between 6 to 12 inches of snow is likely for the central and northern plains through Thursday, particularly in the central portions of the Dakotas, the weather service said in a forecast discussion. The Nebraska Department of Transportation warned that residents could face flooding and blizzard conditions into Thursday. It wasn't just the snow causing disruptions. In New Mexico, the storm's high winds derailed a train on Wednesday, according to state police. Severe thunderstorm warnings also stretched from southwestern Texas to parts of Kansas, according to the weather service. Parts of Wisconsin and Michigan were among the areas under a flash flood watch. Our teams are working to restore jet bridges and clean up from this morning’s severe weather. Flights are arriving and departing as we continue to work with our partners to minimize any customer impacts. pic.twitter.com/ZwMpBX9PTF — DFW Airport (@DFWAirport) March 13, 2019 In Texas, Dallas-Fort Worth recorded gusts of wind between 75 mph and 78 mph early Wednesday. Dallas/Fort Worth International Airport had several jet bridges damaged in Wednesday's storm, and there were cancellations and a number of flight delays, an airport spokesperson said. The terminals were not damaged. In Tennessee and parts of Mississippi, as much as 4 inches of rain could fall through Friday.