major and anomalous storm system is forecast to produce a multitude of weather hazards through early this weekend, as heavy snowfall, strong winds, and dangerously cold temperatures span from the northern Great Basin through the Plains, Upper Midwest, Great Lakes, and the northern/central Appalachians. At the forefront of the impressive weather pattern is a dangerous and record-breaking cold air mass in the wake of a strong arctic cold front diving southward across the southern Plains today and eastward into the Ohio/Tennessee Valleys by tonight. Behind the front, temperatures across the central High Plains have already plummeted 50 degrees F in just a few hours, with widespread subzero readings extending throughout much of the central/northern Plains and northern Rockies/Great Basin. These temperatures combined with sustained winds of 20 to 30 mph and higher wind gusts of up to 60 mph will continue to lead to wind chills as low as minus 40 degrees across a large swath of the Intermountain West and northern/central Plains, with more localized areas of minus 50 to minus 70 possible through the end of the week. Wind chills of this magnitude can cause frostbite in less than 5 minutes if precautions are not taken, with hypothermia and death also possible from prolonged exposure to the cold. Livestock interests will also be severely impacted and dangers could be exacerbated if power outages occur. Consequently, widespread Wind Chill Warnings, Watches and Advisories span across over 30 states from Washington to Florida. Daytime temperatures across the central Plains will struggle to get above 0 degrees, while areas further south in Texas and the Gulf Coast will experience temperatures in the single digits and teens Thursday evening. Furthermore, snow squalls, or a brief burst of moderate to heavy snow (lasting 1 to 2 hours), are likely to occur immediately behind the arctic front as it treks from the mid-Mississippi Valley to the East Coast. Developing snow squalls could lead to extremely hazardous travel conditions at times, as they will be accompanied by gusts to 40 mph and the potential for sudden whiteout conditions. Lastly, areas with standing water ahead of the approaching cold front, particularly throughout the Ohio/Tennessee Valleys, could experience a flash freeze this afternoon and evening. Roadways that were wet beforehand could freeze within a short period of time and lead to slick travel spots. For areas across the Upper Midwest, Great Lakes, and Interior Northeast, a rapidly deepening low-pressure center that forms along the frontal boundary this evening and swings into the Great Lakes on Friday will have the potential to create potentially crippling conditions. Widespread light-to-moderate snowfall is expected for this region, along with localized totals over a foot to the south and east of the Great Lakes where lake effect snow is forecast to linger into Saturday. The snowfall totals may not seem all that impressive with this storm, but combined with very strong winds over an extended period of time will create blizzard conditions that can bring travel to a halt and strain infrastructure. These widespread wind gusts over 40 mph and potentially up over 60 mph are due to a very tight pressure gradient developing between the eventual low over the Great Lakes and the strong high pressure system over the northern Plains. The abrupt deepening of this low pressure system will also aid in the increasingly large and powerful wind field. Heavy snowfall rates of 1-2"/hour, along with wind gusts of over 50 mph will result in near-zero visibility and considerable blowing and drifting of snow. This will lead to dangerous, to at times impossible, land and air travel leading up to the holiday weekend. The combination of heavy snow and strong wind gusts could lead to significant infrastructure impacts, including scattered tree damage and power outages.🌬
