It was undergoing what's called "bombogenesis", on Wednesday afternoon - which means its central pressure has dropped at least 24 millibars in 24 hours.
The weather service said the precipitation will be a wintry mix of rain and heavy snow, but the type depends on the location. "Severe weather will accompany these thunderstorms", NWS said, as the system moves quickly eastward.
"Snow and gusty winds from Ulmer continue from the Colorado Rockies to western South Dakota and much of Wyoming". The weather service office in Midland/Odessa, Texas, said Wednesday could be 'the windiest day in years, USA Today reported.
The National Weather Service reported that Denver International Airport saw wind gusts of up to 75 miles per hour and heavy snow, comparing the winds to a category 1 hurricane.
Amid the expected severe weather, more than 1,200 flights within, into or out of the U.S. were canceled as of Wednesday morning, according to the website FlightAware.
The Weather Channel has dubbed it "Winter Storm Ulmer", and says it's bringing unsafe conditions, high winds, and possible structural damage, such as power outages and downed trees.
Meanwhile, Cheyenne, Wyoming, and Denver, Colorado, are slated to get hit with blizzard conditions soon, said the news outlet. The National Weather Service has issued high wind and winter storm advisories for an area ranging from Colorado and New Mexico over to Nebraska and parts of Texas, and up to South Dakota.
"'We are anticipating some possible delays and cancellations, be sure to check your flight status with your airline". Heavy snow is expected in portions of the Rockies and northern Plains, including Denver into Thursday.
Snow showers will push through the Beehive State Wednesday, according to Dan Guthrie of KSL Weather. It will move through the Upper Mississippi Valley and Upper Great Lakes region on Thursday, NWS said.
The latest update from the Cheyenne Office of the National Weather Service is now calling for up to two feet of snow in some areas, along with unsafe winds and risky travel conditions.
The National Weather Service Denver/Boulder said, "Blizzard conditions are likely across the northern mountains, northern foothills, Palmer Divide and adjacent plains". "Widespread blowing snow will reduce visibility to near zero at times".