Millions of last-minute holiday travelers in the central US are facing dangerous blizzard conditions caused by a developing low-pressure system. This powerful storm, fueled by an El Ni?±o-charged southern jet stream, has already caused problems in Southern California and the Desert Southwest. It is now joining forces with another storm coming from the Pacific Northwest, creating a variety of impactful weather.

While the southern Plains and Gulf Coast will experience soaking rain and a potential flash flood threat, the backside of the storm will bring heavy snow as a cold air mass from Canada moves into the northern US. Blizzard Warnings have been issued for over a half-million people across southeastern and south-central South Dakota and central and northeastern Nebraska. Winter Storm Warnings, Winter Storm Watches, and Winter Weather Advisories are also in effect for other parts of the region, including Wyoming, Colorado, Kansas, and North Dakota.

As of Sunday morning, areas of snow were already extending northeastward from the central Rockies into the central and northern Plains. Up to half a foot of snow had already been measured west of Denver, with 8 inches recorded in Burlington, Colorado. Although minor accumulations were reported in the Denver-Boulder area, it was likely a welcome sight with Christmas approaching.

The forecast for Christmas Eve, Christmas Day, and the week ahead predicts the storm system moving east toward the Mississippi Valley. The low-pressure system is expected to intensify rapidly over the western Midwest on Christmas Day and even more so from Christmas night into Tuesday morning. This intensification will bring strong, gusty winds across the north-central US, increasing the chances of a blizzard in the northern and central Plains. The National Weather Service states that a snowstorm must meet specific criteria to be classified as a blizzard, including sustained winds or frequent gusts of at least 35 mph, considerable falling and/or blowing snow reducing visibility to one-quarter mile or less, and persisting for three hours or longer.

Over a foot of snow is expected along with wind gusts up to 50-55 mph in areas under Blizzard Warnings, with some warnings remaining in effect until Wednesday morning. The impacted areas include portions of Interstate 80, I-29, and I-90. In addition to snow, freezing rain and sleet are predicted to create icy roads from the Plains to Minnesota. Freezing rain is expected to start Christmas morning and spread farther west and north during Christmas night, potentially causing travel disruptions.

The timing of this massive storm will create travel impacts across the Plains and Midwest through Wednesday morning. Parts of the Rocky Mountains, from Montana to Colorado, will experience heavy snow, with up to 2 feet possible in the highest elevations. The northern Plains may also see snow in two batches through Christmas Day, with up to 8 inches possible along the Nebraska-South Dakota border. Minneapolis, Minnesota, may also experience some snowfall.

On the warm side of the storm, heavy rain poses a risk of flash flooding across the South. Rain is expected to begin Saturday night and increase on Christmas Eve, stretching from the Canadian border to the Gulf Coast. Flash flooding is a concern in nearly a dozen southern states throughout the Christmas weekend.

In conclusion, millions of travelers in the central US are facing dangerous blizzard conditions caused by a developing low-pressure system. Heavy snow, freezing rain, and heavy rain are all expected, creating hazardous travel conditions across multiple states. The storm is forecasted to intensify rapidly, bringing strong winds and potentially causing blizzard conditions in the northern and central Plains. Travelers are advised to exercise caution and stay updated on weather forecasts and advisories.